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-- S 38th Ct N Project Location ,arr Rd Neighborhood Detail Map Scale: 1" = 200' Carr Road --- Panther Creek Emergency Culvert Repair Project WETLAND ASSESSMENT Carr Road Panther Creek Emergency Culvert Replacement Project Prepared for City of Renton Public Works Department Renton City Hall 105 South Grady Way Renton, WA 98057 Prepared by Herrera Environmental Consultants 2200 Sixth Avenue, Suite 1100 Seattle, Washington 98121 Telephone: 206/441-9080 June 25, 2008 Wetland Assessment — Carr Road Panther Creek Emergency Culvert Replacement Project Introduction The City of Renton Public Works Department proposes to repair and rehabilitate a culvert underneath Carr Road that conveys Panther Creek. The culvert is located at 9840 Carr Road SE, Renton, Washington. This wetland assessment was prepared in support of a land use permit from the City of Renton. This report provides an assessment of wetlands delineated adjacent to Panther Creek in the project area and in the vicinity of the project. On May 5, 2008, Panther Creek and two adjacent wetlands (Wetlands A and B) were identified and delineated by Jeryl Kolb and Jim Rothwell of Herrera Environmental Consultants (Herrera). The Carr Road culvert consists of a 78-inch diameter, 155-foot long, corrugated metal pipe (CMP). A joint on this culvert, located 32 feet from the downstream outlet, has partially separated and collapsed resulting in formation of a three-foot by two -foot hole within the culvert. As a result, a sink hole at the surface of the road embankment has started to form. In addition, the bottom of the culvert has rusted away beginning at the downstream outlet and extending approximately 15 feet in the upstream direction. This has caused the underlying soil to scour away and wood and debris to become trapped at the base of the culvert. The downstream 32-foot segment of culvert had been a prior culvert extension in the 1970s. The upper portion of culvert appears to be in good condition, with the exception of some minor corrosion and pitting at the downstream invert. This section of pipe downstream of the damaged joint could completely fail at anytime, resulting in a collapse of the northern portion of the embankment supporting Carr Road. This could result in the loss of the sidewalk and the outside lake of Carr Road. If the slope were to fail and block the culvert outlet, the high velocity flows from Panther Creek would continue to erode and weaken the stability of the embankment under Carr Road and ultimately result in the closure of Carr Road, which is a major transportation route within the City of Renton. As a result, the City of Renton Public Works Department has declared repair of this damaged culvert an Emergency Action and intends to repair the culvert in the summer and fall of 2008. Project Elements The proposed project includes two main elements: (1) complete removal of the damaged section of culvert and construction of a new headwal 1, and (2) installation of baffles within the undamaged section of culvert along with rehabilitating the outlet. Both elements will result in environmental benefits by reducing the length of the culvert by over 20 percent, replacing a section of culvert with open stream channel habitat, and by improving fish passage through the undamaged section of culvert. The Washington Department of Fish and Wildlife (WDFW) has documented the use of Panther Creek by coho salmon (Dncorhynchus kisutch), and the stream likely also contains cutthroat trout (Qncorhynchus clarkii). June 25, 2008 1 Herrera Environmental Consultants Wetland Assessment — Carr Road Panther Creek Emergency Culvert Replacement Project The height of the new headwall will be 20 feet and the overall length will be about 35 feet extending out from the culvert outlet. A handrail will be placed at the top of the headwall for safety. To transition from the new culvert outlet to the existing stream, a fish passable boulder cascade is proposed within the limits of the new headwall. This feature will consist of a defined mixture of large boulders placed within smaller rock, sand, and sediment to provide areas of slow stream velocity within the cascade_ The undamaged section of culvert will be rehabilitated with the installation of a concrete paved invert and installation of baffles throughout the culvert. The concrete paved invert will extend 4- inches above the existing invert and is necessary to improve the structural integrity of the culvert because of the existing corrosion and pitting. Baffles will be 7.5 inches high and spaced at 7.5 feet apart. During construction, the bypass of Panther Creek will be achieved by placing a cofferdam upstream of the culvert inlet that will collect stream flow into a 24-inch pipe located within the existing 78-inch diameter pipe. The City of Renton has 2 years of gauge data on Panther Creek at Talbot Road, which indicate that the peak daily flows between August and October are 10 cubic feet per second (cfs). The 24-inch diameter pipe bypass will have a capacity of 22 efs. During construction, the project area will be inaccessible to fish use or passage. There is potential for sedimentation release to the downstream channel; however, temporary erosion and sedimentation measures (TESC) will be implemented to minimize release. TESC measures will include construction limit flagging, silt fencing at down slope extents of construction activity, and measures to collect and haul any contaminated water resulting from sand blasting or other construction activities within the culvert. The edges of the boulder cascade will be planted with willows and all other disturbed areas will be seeded with a native grass seed mix. Methods Wetlands The wetland delineation was performed in accordance with the Washington State Wetlands 7dentifr'eation and Delineation Manual (Ecology 1997), which is consistent with the 1987 Carps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987). The three - parameter approach used to identify and delineate wetlands relies on the presence of field indicators for hydrophytic vegetation, hydric soils, and hydrology. This wetland delineation was performed according to procedures specified under the routine wetland determination method (Ecology 1997). To identify potential wetlands, wetland biologists evaluated field conditions by walking through the entire project area including areas within 200 feet beyond the project limits. For each area that appeared to have wetland characteristics, a test plot was established, and a second test plot established in an adjacent upland area. At each test plot, data on dominant plant species, soil cur xolmd assessmew &x June 25, 2008 ? Herrera Environmental Consultants Wetland Assessment — Carr Road Panther Creek Emergency Culvert Replacement Project conditions in test pits, and evidence of hydrologic conditions were recorded on routine wetland data formes. Adjacent upland areas were also analyzed. On the basis of the collected data, a determination of wetland or upland was made for each area examined. Potential wetland areas in the project area were identified as distinct vegetation units for which the three parameters (hydrophytic vegetation, hydric soils, and hydrology) were evaluated. A vegetation unit is an area that is determined to have relatively uniform plant communities or physical characteristics. Features such as species uniformity, species dominance, distinct topographic breaks, and obvious similarities in soil or hydrologic indicators are factors that define a vegetation unit. After the confirmation of all three wetland parameters, wetland boundaries were delineated by placing flagging along the wetland perimeters. Test plot locations were also marked with flagging. Wetland boundaries were surveyed by PACE Engineers, Inc. Streams The ordinary high water mark (OHWM) of Panther Creek was identified according to the definition of OHWM provided in Washington Administrative Code (WAC) 173-22-030[11 ] and the City of Renton Municipal Code Title IV, Chapter 3, Section 4-3-050(L)1(b)i. According to these definitions, the OHWM on streams is that mark that will be found by examining the bed and banks and ascertaining where the presence and action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation. The OHWM on each side of the stream was delineated by placing (lagging, which was surveyed by PACE Engineers, Inc. Results Wetlands Two wetlands (Wetlands A and B) were located along Panther Creek and their boundaries were delineated. Wetland A Wetland A is located on the right bank (facing upstream) of Panther Creek approximately 205 feet downstream of the Carr Road culvert (Figure 1). Based on the Hydrogeomorphic (HGM) classification system (Brinson 1993), Wetland A contained elements of both riverine and slope wetlands. Based on the U.S. Fish and Wildlife Service (USFWS) classification system (Cowardin et al. 1979), Wetland A is a palustrine emergent wetland. Dominant vegetation in this wetland includes reed canarygrass (Phalaris arundinacea), horsetail (Equisetum arvense), lady fern (Athyrium frlix femina), and black cottonwood (Populus balsamifera). Dominant vegetation cror Herla,rl ocsescme,rr.duc June 25, 2008 3 Herrera Environmental Consultants Wetland Assessment — Carr Road Panther Creek Emergency Culvert Replacement Project within adjacent uplands includes big -leaf maple (Acer macrophyllum), Western red cedar (Thuja plicata), and sword fern (Polystichum munitum). Two test plots were examined at Wetland A: a wetland plot (TP-Al) and an upland plot (TP-A2) (see attached data forms). The hydric soil indicators at the wetland test plot included organic muck overlying dark reddish gray (2.5YR 3/1) sandy loam at 10 inches depth. The hydrologic indicator consisted of saturated soil at the surface and free water in the soil test pit at S inches. The upland test plot exhibited hydrophytic vegetation; however, no wetland hydrology characteristics were present such as saturated soils within a 16-inch soil test pit. In addition, the test plot did not exhibit hydric soil indicators. According to Renton Municipal Code "I"itle IV, Chapter 3, Section 4-3-050(M) I (a), Wetland A is classified as a Category 2 wetland, because it does not meet the criteria for Category 1 or 3 wetlands. Category 2 wetlands require a buffer width of 50 feet. Wetland B Wetland B is located on the left bank (facing upstream) of Panther Creek approximately 23 feet upstream of the Carr Road culvert (Figure 1), Based on the HGM classification system (Brinson 1993), Wetland B contained elements of both riverine and slope wetlands. Based on the USFWS classification system (Cowardin et al. 1979). Wetland B is a palustrine emergent and palustrine scrub -shrub wetland. Dominant vegetation in this wetland includes stinging nettle (Urtica dioica), red -flowering currant (Ribes sanguineum), and salmonberry (Rubus spectabilis). Dominant vegetation within adjacent uplands includes big -leaf maple, Western red cedar, and sword fern. Two test plots were examined at Wetland B: a wetland plot (TP-BI) and an upland plot (TP-B2) (see attached data forms). The hydric soil indicators at the wetland test plot included dark gray (IOYR 4/1) sandy clay soil with dark yellowish brown (IOYR 3/6) mottles. The hydrologic indicator consisted of saturated soil at the surface and free water in the soil test pit at 10 inches. The upland test plot exhibited hydrophytic vegetation; however, no wetland hydrology characteristics were present such as saturated soils within a 16-inch soil test pit. In addition, the test plot did not exhibit hydric soil indicators. According to Renton Municipal Code Title IV, Chapter 3, Section 4-3-050(M)I(a), Wetland B is classified as a Category 2 wetland because it does not meet the criteria for Category I or 3 wetlands. Category 2 wetlands require a buffer width of 50 feet. eor Rellmrdusse+wenid— June 25, 2008 4 Herrera Environmental Consultants Wetland Assessment - Carr Road Panther Creek Emergency Culvert Replacement Project Panther Creek Herrera biologists observed conditions along Panther Creek approximately 70 feet upstream and 315 feet downstream of the Can Road culvert (Figure 1). For each of these reaches the ordinary high water mark (OHWM) of the stream was delineated and flagged on both banks. Upstream of Carr Road, Panther Creek consists of high -gradient riffle habitat approximately 10 feet wide and 0.5 feet deep. Downstream of the road, the stream consists of cascade and high gradient rifle habitats approximately 10 feet wide and 0.5 feet deep. Large gravels are the dominant substrate. According to Renton Municipal Code Title IV, Chapter 3, Section 4-3-050(L) I (a), Panther Creek is classified as a Class 2 water because it is a perennial salmonid-bearing stream. Wetiand Buffer Impacts and Mitigation The project will not impact Wetland A or the regulated 50-foot buffer. While the proposed project will not result in any impacts to Wettand B, the project will temporarily impact a portion of the regulated 50-foot buffer related to installation and removal of a cofferdam that is necessary to bypass stream flow during construction. The cofferdam will be approximately four feet high and constructed of sand or gravel. A 24-inch diameter stream flow bypass pipe will be installed within the cofferdam and extend through the existing culvert underneath Carr Road. Installation and removal of the cofferdam and bypass pipe will disturb herbaceous and shrub vegetation as necessary to transport the materials. After construction, the stream channel will be restored to the original condition and disturbed earth will be seeded with a native grass seed mix. References Brinson, M.M. 1993. A Hydrogeomorphic Classification for Wetlands. Wetland Research Program, Technical report WRP-DE-4. Prepared for U.S. Army Corps of Engineers. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Publication FWS/OBS-79/31. U.S. Department of the Interior, Fish and Wildlife Service, Office of Biological Services. Ecology. 1997. Washington State Wetlands Identification and Delineation Manual. Ecology Publication 96-94. Washington State Department of Ecology, Olympia, Washington. Environmental Laboratory, 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1. U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, Mississippi. cur wllarxl assessor md_ June 25, 2008 5 Herrera Environmental Consultants DATA FORM 1 (REVISED) HERRERA ROUTINE WETLAND DETERMINATION ENVIRONMENTAL Ga'YSLCTLCTANTS TS (WA State Wetland Delineation Manual or 1987 Corps Wetland Delineation Manual Project/Site: Carr Road Panther Creek Emergency Culvert Replacement Project Date: 5/5/08 Applicant/Owner: City of Renton County: King State: WA lnvesti ator s : J. Kolb, J. Rothwell SIT/R: 31rl' 23N/R 5E Do Normal Circumstances exist on the site? Ycs ® No ❑ Community ID: WL-A Is the site significantly disturbed (atypical situation)? Yes ❑ No E Transect ID: Weiland Is the area a potential Problem Area? Yes ❑ No ® Plot ID: TP-AI Explanation of atypical or problem area: VEGETATION (for strata, indicate T = tree; S = shrub: H = herb; V = vine) Plant Species (✓ = Dominant) Stratum %Cover Indicator Plan( Species V = Dominant Stratum %Cover Indicator Phalaris arundinacea ® H 50 FAC W El E uisetum arvense ® H 20 FAC Ath rium ilix- emina ® H 10 FAC— ❑ Po ulus balsamLfera. ® S 20 FAC ❑ ❑ E ❑ HYDROPHYTIC VEGETATION INDICATORS: % of dominants OSL, FACW, and FAC 100 Check all indicators that apply and explain below: Visual observation of plant species growing in Physiological/reproductive adaptations ❑ areas of prolonged inundation/saturation: ❑ Wetland plant database Morphological adaptations ❑ Personal knowledge of regional plant communities Technical Literature ❑ Other (explain) ❑ Hydrophytic vegetation present? Yes N No ❑ Rationale for decision/remarks: Greater than 50 percent of dominants are FAC or wetter. HYDROLOGY Is it the growing season? Yes E No ❑ Water Clarks: Yes ❑ No ® Sediment Deposits: on Yes ❑ No Drill Lines: Yes ❑ No N Drainage Patterns: Based on: soil temp (record temp ) K other (explain) time of year Yes ❑ No Depth of inundation: NA inches Oxidized Root (live roofs) Channels Local Soil Survey: 12 in. Yes ❑ No N Yes ❑ No FAC Newral; Yes ❑ No ® Water -stained Leaves: Depth to free water in pit: 8 inches Depth to saturated soil: 0 inches Yes ❑ No Check all that apply and explain below: Other (explain): Stream, lake. or gauge data: ❑ Aerial photographs: ❑ Other: ❑ Wetland hydrology present? Yes ® No ❑ Rationale for decision/remarks: Soil is saturated to the surface. [bR :ip- Ldo DATA FORM 1 (Routine Wetland Determination) — PAGE 2 SOILS Map Unit Name Al_derwood gravelly sandy loam Drainage Class Moderately well drained (Series & Phase) Taxonomy (subgroup) Entic Durochre is Field observations confirm mapped type? Yes ® No ❑ Profile Description Depth inches Horizon Matrix color Munsell moist Mottle colors Munsell moist Mottle abundance and contrast Texture, concretions, structure, etc. Drawing of soil profile match description) 0-to 1 OYR 2/2 I fibric muck 10-16+ 2.5YR 3/1 sandy loam Hydric Soil Indicators: (check all that apply) 1_ ❑ Histosol ❑ Matrix chroma < 2 with mottles ® Histic Epipedon ❑ Mg or Fe Concretions ❑ Sulfidic Odor ❑ High Organic Content in Surface Layer of Sandy Soils ❑ Aquic Moisture Regime ❑ Organic Streaking in Sandy Soils ❑ Reducing Conditions ❑ Listed on National/l.ocal Hydric Soils List M Gleyed or Low-Chroma (—I) matrix ❑ Other (explain in remarks) Hydrie soils present? Yes M No ❑ Rationale for decision/remarks: Histic epipedon overlying a low chroma soil. WETLAND DETERMINATION Hydrophytic vegetation present? Yes ® No ❑ Hydric soils present? Yes ® No ❑ Wetland hydrology present? Yes ® No ❑ Is the sampling point within a wetland? Yes ® No ❑ Rationale/Remarks: All three wetland parameters are present C .R Rp< f'dx C=q DATA FORM 1 (REVISED) HERRERA ROUTINE WETLAND DETERMINATION ENVIRONMENTAL CONSULITANTiANTS (WA State Wetland Delineation Manual or 1987 Corps Wetland Delineation Manual Preject/Site: Carr Road Panther Creek Emergency Culvert Replacement Project Date: 5/5/08 Applicaiit/Owner. City of Renton County: King State: WA Investi ator s : J. Kolb, 1. Rothwell S/T/R: 31/'1' 23N/R 5E Do Normal Circumstances exist on the site? Yes ® No ❑ Community ID: WL-A Is the site significantly disturbed (atypical situation)? Yes ❑ No ® Transect ID: Upland Is the area a potential Problem Area? Yes ❑ No ® Plot ID: TP-A2 Explanation of atypical or problem area: VEGETATION (for strata, indicate T = tree; S = shrub; 1 I = herb: V = vine) Plant Species ✓ = Dominant Stratum %Cover Indicator Plant Species Dominant Stratum %Cover Indicator Phalaris arundinacea ® H 1 35 I'ACW ❑ E uisetum arvense ® H 20 PAC ❑ Rubus s ectabilis ® S 10 FAC+ ❑ ❑ ❑ ❑ ❑ ❑ ❑ HYDROPHYTIC VEGETATION INDICATORS: % of dominants 013L, FAC W, and FAC 100 Check all indicators that apply and explain below: Visual observation of plant species growing in Physiological/reproductive adaptations ❑ areas of prolonged inundation/saturation: ❑ Wetland plant database Morphological adaptations ❑ Personal knowledge of regional plant communities Technical Literature ❑ Other (explain) ❑ Hydrophytic vegetation present? Yes ® No ❑ Rationale for decision/remarks: Greater than 50 percent of dominants are FAC or wetter. HYDROLOGY Is it the growing season? Yes ® No ❑ Water Marks: Yes ❑ No E Sediment Deposits: on Yes ❑ No Drill Lines: Yes ❑ No ® Drainage Patterns: Based on: soil temp (record temp ) X other (explain) time ofyear Yes ❑ No Depth of inundation: NA inches Oxidized Root (live roots) Channels Local Soil Survey: 12 in. Yes ❑ No ® Yes ❑ No FAC Neutral: Yes ❑ No ® Water -stained Leaves: Depth to free water in pit: >16 inches Depth to saturated soil: >16 inches Yes ❑ No El Check all that apply and explain below: (hher (explain): Stream, lake, or gauge data7 ❑ Aerial photographs: ❑ Other: ❑ Wetland hydrology present? Yes ❑ No Rationale for decision/remarks: Soil is not saturated within the upper 12 inches. CoR 1(1-n2_d DATA FORM 1 (Routine Wetland Determination) — PAGE 2 SOILS Map Unit Name Alder -wood gravelly sandy loam Drainage Class Moderately well drained (Series & phase) Taxonomy (subgroup) Entic Durochre is Field observations confirm mapped type? Yes ® No ❑ Profile Description Depth inches Horizon Matrix color Munsell moist Mottle colors Munscll moist Mottle abundance and contrast Texture, concretions, structure. etc. Drawing of soil profile match description) 0-16+ 1 OYR 2/2 sandy loam Hydric Soil Indicators: (check all that apply) ❑ Histosol ❑ Histic Epipedon ❑ Sulfidic Odor ❑ Aquic Moisture Regime ❑ Reducing Conditions ❑ Gleyed or Low-Chroma (_]) matrix ❑ ❑ ❑ ❑ ❑ ❑ Matrix chroma :,- 2 with mottles Mg or Fe Concretions High Organic Content in Surface Layer of Sandy Soils Organic Streaking in Sandy Soils Listed on National/Local Hydric Soils List Other (explain in remarks) Hydric soils present? Yes ❑ No Rationale for decision/remarks: No hydric soil indicators prescnt. WETLAND DETERMINATION Hydrophytic vegetation present? Yes ® Hydric soils present? Yes ❑ Wetland hydrology present? Yes ❑ No ❑ No No ® Is the sampling point within a wetland? Yes ❑ No Rationale/Remarks: Not all three wetland paramelers are present. (bR hp<2.dv DATA FORM 1 (REVISED) HERRERA ROUTINE WETLAND DETERMINATION ENVfRQNMENTAI CONSLI rANFS (WA State Wetland Delineation Manual or 1987 Corps Wetland Delineation Manual Project/Site: Carr Road Panther Creek Emergency Culvert Replacement Project Date: 5/5/08 Applicant/Owner: City of Renton County: King State: WA Investi ator s : J. Kolb, J. Rothwell STIR: 32/T 23N/R 5E Do Normal Circumstances exist on the site? Yes ® No ❑ Community ID: WL-B Is the site significantly disturbed (atypical situation)? Yes ❑ No ® "hransect ID: Wetland Is the area a potential Problem Area? Yes ❑ No ® Plot ID: TP-131 Explanation of atypical or problem area: VEGETATION (for strata, indicate T = tree; S = shrub: H = herb; V = vine) Plant Species ✓ = Dominant Stratum %Cover Indicator Plant Species ✓ = Dominant Stratum % Cover Indicator Urlica dioica ® H 2 FAC f ❑ Ribes san uineum ❑ S 2 Nt ❑ Rubus s ectabilis ® S 20 I'ACr ❑ ❑ ! ❑ ❑ _".. ElEl_ ❑ HYDROPHYTIC VEGETATION INDICATORS: % of dominants OBL, FACW, and FAC; 100 Check aft indicators that apply and explain below: Visual observation of plant species growing in Physiological/reproductive adaptations ❑ areas of prolonged inundation/saturation: ❑ Wetland plant database Morphological adaptations ❑ Personal knowledge of regional plant communities Technical Literature ❑ Other (explain) ❑ Hydrophytic vegetation present? Ycs ® No ❑ Rationale for decision/remarks: Greater than 50 percent of dominants are FAC or wetter" HYDROLOGY Is it the growing season? Yes ® No ❑ Arater Marks: Yes ❑ No ® Sediment Deposits: on Yes ❑ No Drill Lines: Yes ❑ No ® Drainage Patterns: Based on: soil temp (record temp ) X other (explain) time of year Yes ❑ No Depth of inundation: NA inches OXidiMi Root (live roots) Channels Local Soil Survey: ' l2 in. Yes ❑ No ® Yes ❑ No _ _ FAC Neutral: Yes ❑ No ® Water -stained ].eaves: Depth to free water in pit: 10 inches Depth to saturated soil: 0 inches Yes ❑ No Check all that apply and explain below: Other (explain): Stream, lake, or gauge data: ❑ Aerial photographs: ❑ Other: ❑ Wetland hydrology present? Yes ® No ❑ Rationale for decision/rcmarks: Soil is saturated to the surface DATA FORM 1 (Routine Wetland Determination) — PAGE 2 SOILS Map Unit Name Alderwood gravelly sandy loam Drainage Class Moderately well drained (Series & Phase) mm Taxonomy (subgroup) Entic Durochre is Field observations confirm mapped e? Yes ❑ No Profile Descrintion Depth Matrix color Motile colors Mottle abundance Texture, concretions, Drawing of soil profile inches Horizon Munsell moist Munsell moist)_and contrast structure, etc, match description) 0-14 1 OY 4/1 10YR 3/6 few, medium, sandy clay prominent 10YR 3!2 many, coarse, prominent 14-16 10YR 2/2 sandy clay Hydric Soil Indicators: (check all that apply) ❑ Histosol ❑ Histic Epipedon ❑ Sulfidic Odor ❑ Aquic Moisture Regime ❑ Reducing Conditions ® Gleyed or Low-Chroma(=1) matrix Hydric soils present? Yes ® No ❑ Rationale for decisioniremarks: Gleyed soil with redox features. WETLAND DETERMINATION Hydrophytic vegetation present? Yes ® No ❑ Hydric soils present'? Yes ® No ❑ Wetland hydrology present? Yes ® No ❑ Rationale/Remarks: All three wetland parameters are present ❑ Matrix chroma < 2 with mottles ® Mg or Fe Concretions ❑ High Organic Content in Surface Layer of Sandy Soils ❑ Organic Streaking in Sandy Soils ❑ Listed on National/Local Hydric Soils List ❑ Other (explain in remarks) Is the sampling point within a wetland? Yes ® No ❑ cop fµdl.&- HERRERA EIVOROWFWAL CONSUTANTS Project/Site: DATA FORM 1 (REVISED) ROUTINE WETLAND DETERMINATION (WA State Wetland Delineation Manual or 1987 Corps Wetland Delineation Manual Carr Road Panther Creek Emergency Culvert Replacement Project Date: 515/08 Applicant/Owner: City of Renton County: King State: WA Investi ator s : J. Kolb, J. Rothwell S/TiR: 32/T 23N/R 5E Do Normal Circumstances exist on the site? Yes ® No ❑ Community ID: WL-B Is the site significantly disturbed (atypical situation)? Yes ❑ No ® Transect ID: Upland Is the area a potential Problem Area? Yes ❑ No ® Plot ID: TP-132 Explanation of atypical or problem area: VEGETATION (for strata, indicate T = tree; S shmh; I I -- herb; V = vine) Plant SDecies (V = Dominant) itratntn %f'ovvr tndiraii�r Punt Cnrrirc i✓ = tlnminant) Crrati m a/ ('n, r„a"t. Pol stichum munitum ® H 15 FACU ❑ Thu'a plicala ® S 15 FAC ❑ ❑ Rubus s ectabilis ® S 20 _ 1=AC'— ❑ ❑ ❑ ❑ ❑ ❑ HYDROPHYTIC VEGETATION INDICATORS: % of dominants OBL, FACW. and FAC 66 Check a[] indicators that apply and explain below: Visual observation of plant species growing in Physiological/reproductive adaptations ❑ areas of prolonged inundation/saturation: ❑ Wetland plant database Morphological adaptations ❑ Personal knowledge of regional plant communities Technical Literature ❑ Other (explain) ❑ Hydrophytic vegetation present? Yes ® No ❑ Rationale for decision/remarks: Greater than 50 percent of dominants are FAC or wetter. HYDROLOGY Is it the growing season? Yes ® No ❑ Water Marks: Yes ❑ No ® Sediment Deposits: on Yes ❑ No Based on: soil temp (record temp ) Driit lines: Yes ❑ No ® Drainage Patterns: X other (explain) time of year Yes ❑ No Depth of inundation: NA inches OxidizL d (toot (live roots) Channels Local Soil Survey: 12 in. Yes ❑ No ® Yes ❑ No EJ Depth to free water in pit: >16 inches FAC Neutral: Yes ❑ No ® Water -stained Leaves: Depth to saturated soil: > 16 inches Yes ❑ No JZ Check all that apply and explain below: Other (explain): Stream, lake, or gauge data: ❑ Aerial photographs: ❑ Other: ❑ Wetland hydrology present? Yes ❑ No Rationale for decision/remarks: Soil is not saturated to the surface Colt iep-h2d, c DATA FORM 1 (Routine Wetland Determination) — PAGE 2 SOILS Map Unit Name Alderwood Zravclly sandy loam Drainage Class Moderately well drained (Series & Phase) Taxonomy (subgroup) Entic Durochre is Field observations confirm mapped e? Yes ® No ❑ Profile Description Depth inches Horizon Matrix color Munsell moist Mottle colors Munsell moist Mottle abundance and contrast Texture, concretions, structure, etc_ Drawing of soil profile match description) 0-8 I OYR 3/2 sandy clay loam 5-16+ IOYR 4/3 7.5YR 3i4 few, fine, sandy clay loam prominent Hydric Soil Indicators: (check all that apply) ❑ Histosol ❑ Matrix chroma _5 2 with mottles ❑ Ilistic Epipedon ❑ Mg or Fe Concretions ❑ Sulfidic Odor ❑ High Organic Content in Surface Layer of Sandy Soils ❑ Aquic Moisture Regime ❑ Organic Streaking in Sandy Soils ❑ Deducing Conditions ❑ Listed on National/Local Hydric Soils List ❑ GIeved or Low-C'hroma (= I ) matrix ❑ Other (explain in remarks) Hydric soils present? Yes ❑ No Rationale for decision/remarks: No hydric soil indicators arc present. WETLAND DETERMINATION Hydrophytic vegetation present? Yes ® No ❑ hydric soils present? Yes ❑ No Wetland hydrology present? Yes ❑ No ® Is the sampling point within a wetland? Yes ❑ No Ration alef Remarks. Not all three wetland parameters are present. N 2s so LEGEND: zs o �------- HOR. SCALE: 1" = 50' ' WATER VALVE LI WATER METER I I: MANHOLE (SS75O) CB POWER/UTILITY POLE GUY ANCHOR y SIGN WETLAND CONIFEROUS TREE DECIDUOUS TREE FOUND CASED MONUMENT L - TEST PIT WETLAND FLAG & DESIGNATION �p ORDINARY HIGH WATER MARK WETLAND BUFFER CULVERT WETLAND - _ ] �g � I I I :oan TERRAr'F. 4e L c L s l'NfLiTTcD � LOT �1 LOT 41 LOT 40 — - - 6 - - = = CARR ROAD 1 r"'� P 32rp0 LOT 23'1 T 1 1 r v C I\14FLATTHD VAI.LFY YIHW HFA II'I'4 ! \ - - \ k-:�`, i. RF u4 CONDO. VOL 119:38-42 IL J WETLAND B * / ooHERRERA EFMROAWAIrAL LZJNSULTANTS Figure 1. Wetlands A and B; and Panther Creek in the vicinity of the Carr Road Panther Creek Emergency Culvert Replacement Project, Renton, Washington. GEOTECHNICAL ENGINEERING REPORT CARR ROAD — PANTHER CREEK CULVERT REPAIR RENTON, WASHINGTON HWA Project No. 2008-051-21 June 25, 2008 Prepared for: R.W. Beek !! ul HWAGEOSCIENCES INC. June 25, 2008 HWA Project Number 2008-051-21 R.W. Beck 1001 Fourth Avenue, Ste 2500 Seattle, WA Attention: Mr. Mike Giseburt Subject: Geotechnical Engineering Report Carr Road — Panther Creek Culvert Repair Renton, Washington Dear Mr. Giseburt: As authorized per the professional services agreement entered between R.W. Beck and HWA Geosciences Inc. (HWA), dated May 20, 2008, we are pleased to present this report with regard to the Carr Road - Panther Creek Culvert Repair Project. The objective of our investigation was to evaluate site subsurface conditions and provide geotechnical design and construction recommendations for the repair or replacement of the failed culvert section. PROJECT DESCRIPTION We understand that the project consists of repairing or replacing the damaged section, and the lining of the remaining length. of a 155-foot long, 78-inch diameter corrugated steel pipe culvert. The culvert conveys the Panther creek under Carr road approximately 350 feet east of the intersection of Carr Road and Smithers Avenue South, as shown in Figure 1. We understand that the northern 30 feet of the culvert has become detached from the remaining culvert and that a small surficial slide has occurred in the fill slope directly above the location of the culvert failure. It is also our understanding that replacement will involve excavating down to the location where the pipe has failed, and that shoring will be needed to protect Carr Road during installation of a new 30 foot section at the north end of the culvert. The remaining 125 feet of the culvert will need to be lined in order to prevent further damage and corrosion. FIELD AND LABORATORY INVESTIGATIONS SUBSURFACE INVESTIGATION Subsurface investigations for the proposed improvements consisted of one borehole, designated BH-1, to a depth of about 70 feet below ground surface through the existing road surface on the west side of the existing culvert, and one June 25, 2008 HWA Project No. 2008-051-21 hand hole along with, a Drop Weight Cone Penetrometer (DCP) sounding at the outfall of the culvert. Figure 2, Site and Exploration Plan, shows the approximate locations of the subsurface investigations. An HWA geologist monitored and logged the subsurface explorations and obtained representative soil samples. Soil samples obtained from the explorations were classified in the field and representative portions were placed in plastic bags and returned to our Lynnwood, Washington, laboratory for testing. Field exploration methods are described in detail and logs of our explorations are presented in Appendix A. It should be noted that the stratigraphic contacts shown on the individual exploration logs represent the approximate boundaries between soil types; actual transitions may be more gradual. The soil and ground water conditions depicted are only for the specific date and locations reported and, therefore, are not Necessarily representative of other locations and times. LABORATORY TESTING Laboratory tests were conducted on selected samples obtained from the exploratory boring BH-1, to characterize relevant engineering and index properties of the site soils. Laboratory tests included detennination of in -situ moisture contents, Atterberg Limits and grain size distribution. The tests were conducted in general accordance with appropriate American Society of Testing and Materials (ASTM) standards. The test results and a discussion of laboratory test methodology are presented in Appendix B, or displayed on the exploration logs in Appendix A, as appropriate. SITE CONDITIONS SITE DESCRIPTION The site is located in Renton, Washington approximately 350 feet east of the intersection of Carr Road and Smithers Avenue South, as shown in Figure 1. Ths site is situated at approximately 175 feet El. above sea level in the highlands just east of the Duwamish River Valley. Overall the site vicinity slopes to the west toward the 1711warnish River Valley, At this particular location Carr Road slopes to the west at a 5,5% grade. Panther Creek flows from Panther Lake to the Duwamish Valley and is an erosional environment for its entire length. The fill embankment and the side slopes of the stream channel on either sides of the culvert are very steep with grades ranging from 70-75%. The culvert conveys Panther Creek from South to North underneath Carr Road and consists of a 78" diameter corrugated steel pipe. The pipe is approximately 155 feet long with a total elevation change of 7 feet. The first 125 feet commencing at the south -end is at a grade of 4.6% and the last 30 feet is at a grade of 4.1 %. On the northern side of Carr 2009-051 I R.doc 2 HWA GEQSCIF.NCES INC. June 25, 2008 HWA Project No.2008-051-21 Road, adjacent to our borehole location, the depth of the pipe is 28 feet below ground surface. The northern most 30 feet of the culvert at the outfall has dropped down below the undisturbed section of culvert by 2 feet. The pipe bottom has rusted out 30 feet upstream from the original outfall, and additionally all of the foundation soils have been eroded. A sinkhole or slide scarp has formed over the culvert failure location, which is 7 feet tall by 12 feet wide. Water is visible at the surface in the slide deposit and at locations of similar elevation seeping out of the road fill embankment on the north side of Carr Road. GENERAL GEOLOGIC CONDITIONS Background geologic information was obtained from the Geologic Map of Renton Quadrangle, King County, Washington (Mullineaux, D.R., 1965). This map identifies the surficial deposits in the immediate vicinity of the proposed culvert repair as Pleistocene aged glacial soils deposited during the Vashon Stade, consisting of Vashon glacial till underlain by undifferentiated deposits. Vashon glacial till consists of an unstratified diamicton with silts, sands and gravels. The undifferentiated deposits consist of three or more till sheets deposited prior to the Vashon-stade glaciation. Both deposits have been over consolidated by the weight of overlying glacial ice during the Pleistocene age. Local outcrops of the Renton Formation bedrock along steep hillsides, to the north are also present within the vicinity of the site. SUBSURFACE CONDITIONS The results of our subsurface explorations generally agree with the geologic map description except that the Vashon till deposit was not encountered; most likely due to the incising of Panther Creek and erosion of the deposit at this location. The underlying undifferentiated deposits described in the geologic reap (Mullineaux, D.R., 1965) were encountered including the Renton Formation at depth. Below the asphalt pavement, the borehole encountered about 30 feet of fill, consisting of loose to medium dense, silty sand with gravel and very stiff sandy silt, over three feet of medium dense stream deposits over very dense and hard glacial deposits and bedrock. A stratigraphic profile of the subsurface conditions encountered can be seen in Figure 3. The following are descriptions of the units encountered during the exploration program, in the order encountered: HMA Pavement: The pavement consisted of a 9-inch layer of hot mix asphalt concrete (HMA). The HMA appears to be constructed directly over the fill without an intervening layer of crushed base material. 2008-051 FR.doc 3 HWA GEOSCIENCES INC. June 25, 2008 HWA Project No. 2003-051-21 recommend construction of a shoring wall to facilitate excavation for replacement of the culvert. Significant caving of the fill and alluvium should be anticipated for unshored excavations or uncased drill hales. Our recommendations regarding temporary shoring, soldier pile construction, slope stability, and culvert replacement are presented in the following sections. SEISMIC DESIGN CONSIDERATIONS Seismic Parameters For this project, it may be appropriate to use a 10% Probability of Excedence (PE) in 50 years event (approximately 475-year return period) for both retaining wall design and slope stability analyses. Table 1 provides the parameters needed for use with the 2006 IBC design procedures which were based on data from the United States Geologic Survey Hazard Mapping Project (2002). Table 1— Probabilistic Ground Acceleration Parameters per USGS Probability of Return Pear Ground 0.2 sec Spectral 1.0 sec Spectral Exceedanec Period Acceleration Response Response (PGA) Acceleration Acceleration 10% in 50 years 475 year 0.32 0.72 0.24 Liquefaction Considerations Our liquefaction analyses, based on cyclic stress ratio concepts developed by Seed and Idriss (Seed, H.B., Idriss, I.M., 1982), indicate that the wet sand zone below the existing road embankment will liquefy during strong earthquakes. The existing embankment is not designed to withstand against liquefaction induced by a strong earthquake. Therefore it is not reasonable to retrofit the embankment or to design the proposed culvert repair against potential liquefaction of the inundation soil. We do not recommend a liquefaction proof repair design on the culvert, unless the City wants to retrofit the entire embankment foundation soils. SHORING Replacing the culvert needs significant excavation into the embankment which consists of loose to medium dense silty sand to very stiff sandy silt. Any excavation into the existing road bank will destabilize the slope and road surfaces can be affected. To prevent road embankment failure due to the anticipated excavation, the area should be shored with either sheet piles or soldier piles. 2008-051 PR.doc 5 HWA GF:OSCIENCES INC. June 25, 2008 1IWA Project No, 2008-051-21 Sheet pile installation by means of a vibratory hammer into the very dense sand would cause significant disturbance which can cause the road surface to settle or interrupt the underground utility lines in the vicinity. Due to anticipated severe caving conditions, using earth auger type equipment with combination of steel casings will be difficult and should not be allowed for installing soldier piles at this site. Therefore, a hollow stem auger mounted on a crane should be used to drill soldier pile holes and fill the holes with low strength grout. After each hole is drilled, the H beam should be lowered in. Hollow stem auger (auger cast pile rig) mounted on a crane with a diameter of 16 inches or so is commonly available locally in the Puget Sound region. For piles greater than 16 inches in diameter, pile driving equipment such as a 15,000 ft-lb Vulcan hammer will be necessary to install piles into drilled holes in order to reach the desired pile tip elevation. There are two ways to analyze the pile, as 1) cantilever soldier pile wall and 2) braced excavation with soldier pile wall. Cantilever soldier pile wall Cantilever soldier pile walls can be design for the excavation and shoring with the lateral earth pressure diagram shown on Figure 4. Braced soldier pile wall Braced walls are normally designed with an apparent pressure design diagram developed by Terzaghi and others by measuring the earth pressures during temporary excavation phase. This concept was used to develop the diagram presented on Figure 5 for the temporary and permanent wall designs. In the normal circumstances, the passive pressures are almost negligible in that the bottom bracings take up the lateral earth loads. In our case herein, the excavation is not fully enclosed with shoring. Therefore, the sliding forces from the road embankment should be resisted by passive pressure using the soldier piles which need to be embedded into the competent glacial soils. SLOPE STAWLITY Our slope stability analyses for static loading not including earthquake loading condition indicate that the existing road embankment has a factor of safety near unity, therefore it is on the verge of failure or currently barely standing. Mitigating Slope Stability The wall should be constructed high enough to place backfill with a 5-foot wide bench adjacent to the wall, with the slope above it at 2H:1 V or flatter. The road fill was 2008-051 FR.doc 6 HWA GEOSCIENCES INC- June 25, 2008 H WA Project No. 2008-051-21 primarily loose and can not be trusted for fixed anchors unless a high pressured grout system is used. CONSTRUCTION REQUIREMENTS Quality Assurance The steel soldier piles shall be placed so that the centerline of the pile at the top is within 1-inch of the plan location. The steel soldier pile shall be plumb, to within 0.5 percent of the length based on the total Iength of the pile. Submittals The Contractor shall submit shop plans as specified in Section 6-03.3(7) (2006 WSDOT M41-10 Standard Specifications for Road, Bridge and Municipal Construction) for all structural steel, including the steel soldier piles to the Engineers for approval. The Contractor shall submit copies of a soldier pile installation plan prior to the beginning of wall construction. In preparing the submittal, the Contractor shall reference the available boring logs provided in the contract documents and the geotechnical report prepared for this project. This plan shall provide at least the following information: 1. An overall construction operation sequence and the sequence of soldier pile construction. 2. List, description, and capacities of proposed equipment including but not limited to cranes, drills, and augers. The narrative shall describe why the equipment was selected, and describe equipment suitability to the anticipated site and subsurface conditions 3. Details of pile installation methods including proposed drilling methods, and a review of method suitability to the anticipated site and subsurface conditions. Work shall not begin until the Engineer has approved the appropriate submittals in writing. Corrosion Protection of Soldier Piles The steel soldier piles for the excavation depth plus 5 feet shall be treated with epoxy coating or equivalent for corrosion protection purposes. 2008-051 FR.doc 7 HWA GEOSCIFNCES INC. June 25, 2008 HWA Project No. 2008-051-21 Installing Timber Lagging The excavation and removal of lean concrete for the lagging installation shall proceed in advance of the lagging. The bottom of the excavation in front of the wall shall be level. The bottom of excavation shall be not more than three feet below the bottom level of the timber lagging already installed. Timber lagging for the walls shall be treated. The lagging shall be installed from the top of the pile proceeding downward. The timber lagging shall make direct contact with the soil. Voids shall be filled with gravel backfill for walls, which shall be considered incidental to the installation of the timber lagging. Where timber lagging and gravel backfill are above the existing or excavated ground line, the lagging and backfill shall be placed concurrently. The backfill layers shall be placed and be compacted to 90 percent of maximum density in accordance with the plans. All soil and other waste spoils should be removed from the site at the contractor's expense. The Contractor must exercise care during the excavation and backfilling process to ensure that the existing roadway is not undermined and additional sliding is prevented. This may necessitate excavation and replacement of soils in a sequential or progressive fashion. The method and timing of soil excavation and backfilling behind the wall must be described in the Contractor's submittals. CULVERT / STORM SEWER PIPE REPAIR The existing culvert flow should he maintained during the construction by connecting temporary piping to the existing culvert and routing the flow around the jobsite to a suitable discharge location. This can be done by using a large diameter HDPE pipe sleeve installed within the existing culvert and daylighted to the creek bed far enough away from the road embankment. Armoring of the temporary discharge location may be required. Imported granular backfill for walls and around the new culvert should be placed in loose horizontal lifts less than 8 inches thick, and compacted to at least 92 percent of the maximum dry density (ASTM D 1557). Imported backfill for walls should consist of clean, free -draining, granular soils that are free from organic matter or other deleterious materials. Such materials should comprise particles of less than 4-inch maximum dimension, with less than 5 percent fines, as specified for "Gravel Backfill for Walls" in Section 9-03.14 (1) of the 2008 WSDOT Standard Specifications. Riprap rocks, of 8-inch minus gradation, should be installed at the creek bed and then covered with 4-inch minus rounded cobbles and gravel, or other granular materials, as may be required by the Washington Department of Fish and Wildlife (WDFW) and/or other applicable regulatory agencies should be placed for fish friendly creek bed. 2008-051 FR.doc 8 HWA GEOSCIENCE5 INC June 25, 2008 HWA Project No. 2008-051-21 CONDITIONS AND LIMITATIONS We have prepared this report for the City of Renton and R.W. Beck for use in design of a portion of this project. This report should be provided in its entirety to prospective contractors for bidding and estimating purposes; however, the conclusions and interpretations presented in this report should not be construed as a warranty of existing subsurface conditions. Experience has shown that soil and ground water conditions can vary significantly over small distances. Inconsistent conditions can occur between exploration locations and may not be detected by a geotechnical study of this nature. If, during future site operations, subsurface conditions are encountered which vary appreciably from those described herein. HWA should be notified for review of the recommendations of this report, and revision of such if necessary. Sufficient geotechnical monitoring, testing, and consultation should be provided during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should conditions revealed during construction differ from those anticipated, and to verify that geotechnical aspects of construction comply with the contract plans and specifications. Within the limitations of scope, schedule and budget, HWA attempted to execute these services in accordance with generally accepted professional principles and practices in the fields of geotechnical engineering and engineering geology in the area at the time the report was prepared. No warranty. express or implied, is made. The scope of our work did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or ground water at this site. This firm does not practice or consult in the field of safety engineering. We do not direct the contractor's operations, and cannot be responsible for the safety of personnel other than our own on the site. As such, the safety of others is the responsibility of the contractor. The contractor should notify the owner if he/she considers any of the recommended actions presented herein unsafe. .p We appreciate the opportunity to provide geotechnical services on this project. Should you have any questions or comments, or if we may be of further service, please do not hesitate to call. Sincerely, 2008-051 FR.doc 9 HWA GEOSCI} NCES INC. June 25, 2008 HWA Project No. 2008-051-21 HWA GEOSCIENCES INC. Sa H. Hong, P.E. Geotechnical Engineer, Principal ATTACHMENTS Figure 1: Project Site Location and Vicinity Map Figure 2: Site and Exploration Plan Figure 3: Crass -Section A -A" Figure 4: Cantilever Wall Design Pressure Diagram Figure 5: Braced Wall Design Pressure Diagram APPENDICES Appendix A: Field Exploration Figure A-1 Legend of Terms and Symbols Used on Exploration Logs Figure A-2 Borehole Log BH-1 Figure A-3 Hand hole I.og II11-1 Appendix B: Laboratory Testing Figure B-1 Plasticity Chart Figure B-2 Grain Size Distribution Charts REFERENCES: Mullineaux, D.R., 1965, Geologic 1nar? vfthe Renton quadrangle, King County, Washington: U.S. Geological Survey, Geologic Quadrangle Map GQ-405, scale 1:24000. 2008-051 rR.aoc 10 HWA GI;OSciENc+s INc. 1L + wrr•q u a .-n,u.� we c�m�u4 mr wr�v wmle u® uaw �� 4W ft ScA: l • AM DBetml• 135 Do= WC5N SITE VICNITY MAP I FIGURE NO. CARR ROAD - PANTHER CREEK U � HWAGEOSCIENCES INC. CULVERT REPAIR �Ro��crNo RENTON, WASHINGTON 2008-051 A'a'aa I E k/7 s SS$j AVER.$siE dJ yPO -0 " o v7 dW� 4 I r 4�ED dt 4 .Q b IV z 4\ LLJ w _ z V 1� r- S_ \ M fo LEGEND i m 80.5E MAP PROVIDED BY --21 CARR A I 1 �I 18 1E 7B" CMP CULV-143.1 150 �1 1�a 130 120 11a 100 BOREHOLE DESIGNATION N-VALUES (BLOW COUNT) GROUND WATER SEEPAGE WATER LEVEL INFERRED GEOLOGIC CONTACT BOTTOM OF BORING IE OF DAMAGED 78' CMP=144.4 rri En L- L. D CULV-150A •• 7 C 53 45' 50/6"- 50/s' -. —? . 507: 50/6" sM [UNDIFFERENTIATED GLACIAL DEPOSITS] SM [SANDSTONE BEDROCK] - 7—?—?�-.—?--... [CLAYSTONE BEDROCK] HORIZONTAL SCALE, 1 20' 0' 10' 20' 40' 0' 10' 20' 40' VERTICAL SCALE: 1 "=20' MWA I HWAGCOSCIEt10ES INC A" I 190 180 Lx- 170 0 Q 160 Ld -150 -1 40 -130 120 110 100 THE SUBSURFACE CONDITIONS SHOWN ARE BASED ON WIDELY SPACED BORINGS AND TEST PITS AND SHOULD BE CONSIDERED APPROXIMATE. FURTHER, THE CONTACT LINES SHOWN BETWEEN UNITS ARE INTERPRETIVE IN. NATURE AND MAY VARY LATERALLY OR VERTICALLY OVER RELATIVELY SHORT DISTANCES ON SITE. Carr Road - Panther Creek Culvert Repair Renton, Washington CROSS SECTION A -A' DRAWN RY EPK UECX BY D PROJECT NO. DATE 06.04.0-8 2008-•051-21 12' MIE EMBEDr DENSE CANTILEVER SOLDIER PILE WALL -21 CARR ROAD - PANTHER CRE)EK CULVERT D DRILLED DIAMETER OR PILE ➢IMENSI❑NS WHICHEVER IS GREATER, NOT TO SCALE 3 .11 - teral pressure Parameters I ; ....... .cove La r ..l. I ' i _ Road fill frictional angle (degrees) 301 p-y modulus Unit Weight (pcf) 110# 30 pcii Backfill slope angles Level Backfill 2H:1V 1,5H; 1V Static lateral earth pressure coefficient, Ka 0.33 0.46 0.5 Active below water table 0.17 0.23 0.25 Dynamic lateral earth pressure coeff. Kae 0.44 0.8 1 EFW, pcf, static 36.7 50.8 55 EFW, pcf, static plus dynamic _ _ 48.5 88 110 - Or 112 *(dynamic-static)*H, psf, dynamic 6H _ 19H - 25HI. !EFW= Equivalent fluid Unit Weight, pcf ;Resultant force far the dynamic lateral earth pressure is applied at 1/2 H iDynam.ic companen#s are converted to uniform loadings such as BH psf i 1. -- ..... . !Traffic loading is not included due to a sufficient distance from the excavation, i.e.. greater € than H. ....... . . - . Permanent timber lagging design pressure 112 of Active Wall Pressure including EQ.„ _.._. ----------- I i I i Passive Pressure Parameters _ I 1 I Over 3 times D Depth below the excavation Passive Resistance (feet) Soil below excavatior: in pcf! 0 to 5 Disturbed creek_be_d 0;too disturbed 5 to 8 Glacial SM 3001weathered 8 to 22 Glacial till 15001intact 22to- Bedrock 2500,intact i I ; Passive resisance reduction 10 percent should be applied for 1 ....... ._....... .... ;earthquake loading condition. i .... - Due to slide condition, a minimum 12 feet embedment into dense soil is needed - --5----- - .. I ---------- I ' ' �L-Pile Design Parameters I Depth below the excavation P Y modulus (Reese mod Soli Strengths Unit Wt. (feet) ... Soil below excavation Soil mode Modulus, k, pci and c pcf ... ..:.. E 0 to 5 Disturbed creek bed sand 10 20° 110 Glacial SM sand 300 5 to 8 430 135 ' 8 to 22 5000 ps ... 138 Glacial till — clay 1000 Bedrock clay 2000 22 to - - -'- 8000 psi 140 .........._.. .....................1. _.-.... ................. ... ...........I .......... L... H'V�A.GEoSCHNCBINC (MWA IL Carr Road - Panther Creek Culvert Repair Renton, Washington g CANTILEVER WALL DESIGN PRESSURE DIAGRAM DRAWN BYE! FIGURE NO, 4 CHECK BY PROJECT N0. 2008-051-21 DATE 06.23.08 12' IN - MA p=Ka.y*H for permanent wall or p=0.65xEKa*Y*H for temporary wall Ka from Figure 4 7=110 pcf uniform dynamic for each back -slope from _.Figure 4. ...... ..... -.........._ NOT TO SCALE BRACED WALL DESIGN PRESSURE DRAWN BYEFK FIGURE NO, L1�,►T T�� DIAGRAM�r Tr�+1�AGEOSCENM INC. Carr Road - Panther Creek CHECK BY SH MWA PROJECT NO. Culvert Repair DATE 2008-051-21 RanFnn W—kir.n4— 06.23.08 APPENDIX A FIELD EXPLORATION APPENDIX A FIELD EXPLORATION A geotechnical subsurface exploration program was conducted by HWA in May, 2008. The field investigation consisted of drilling and sampling one exploratory machine boring designated BH-1 and hand boring HH-1. The exploration locations were located in the field by taping from existing site features, and are shown on the Site and Exploration Plan, Figure 2. A legend of terms and symbols used on the exploration logs is presented on Figure A-1. Logs of borings BH-1 and HH-1 are presented on Figures A-2 and A-3. The borehole, BH-1 was drilled on May 9'h, 2008 by Holocene Drilling of Fife, Washington operating under subcontract to HWA. The boring was drilled with a truck - mounted drill rig, with hollow -stem auger methods. The boring was advanced to a depth of 70.5 feet below the existing ground surface. The borehole was abandoned (in accordance with Ecology requirements) by backfilling with bentonite chips upon completion of drilling. Soil samples were collected at 2-foot and 5-foot intervals using Standard Penetration Test (SPT) sampling in general accordance with ASTM D-1586_ SPT sampling consisted of using a 2-inch outside diameter, split -spoon sampler driven with an automatic 140-pound drop hammer. During the test, a sample was obtained by driving the sampler 18 inches into the soil with the hammer free -falling 30 inches per stroke. The number of blows required for each 6 inches of penetration was recorded. The Standard Penetration Test ("N-value") of the soil is calculated as the number of blows required for the final 12 inches of penetration. If a total of 50 blows was recorded within a single 6-inch interval, the test was terminated, and the blow counts are recorded as 50 blows for the number of inches of penetration. This N-value provides an indication of the relative density of granular soils and the relative consistency of cohesive soils. The boring was advanced under the full-time observation of an HWA geologist. Hand boring HH-1 was advanced on May 91", 2008 utilizing a hand bucket auger. The hand boring was terminated at about 1.7 feet below existing ground surface due to caving of side walls. Soil samples obtained from the borings 4vere classified in the field and representative portions were placed in plastic bags. These soil samples were then returned to our Lynnwood, Washington, laboratory for further examination and testing. Pertinent information including soil sample depths, stratigraphy, soil engineering characteristics, and ground water occurrence was recorded. The stratigraphic contacts shown on the individual logs represent the approximate boundaries between soil types; actual transitions may be more gradual. The soil and ground water conditions depicted are only for the specific dates and locations reported and, therefore, are not necessarily representative of other locations and times. 2008-057-21 Final Report HWA GFoSCIENCES INC. RELATIVE DENSITY OR CONSISTENCY VERSUS SPT N-VALUE COHESIONLESS SOILS COHESIVE SOILS Approximate Approximate Density N (hhwsni) Consistency N;Nowsrfl) Undrained Shear Relative Density{%} Strength (psf) Very Loose 0 to 4 0 - 15 Very Soft 0 10 2 �250 Loose 4 to 10 15 - 35 Son 2 to 4 250 - 500 Medium Dense 10 to 30 35 65 Medum Stiff 4 10 8 Soo - 1000 Dense 30 to 50 65 - 85 Stitt 6 to 15 ID00 - 200D Very Dense over 50 85 - 100 Very Stiff 15 to 30 2000 - 4000 Hard over30 �4000 USCS SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS Course Gravel and Clean Gravel Owl s GW Mu -graded GRAVEL Grained GravefiySoils {htllaorrnofnles) Sails u (1 v GP Paoflygraded GRAVEL More than 50% of Coarse Gravel with a GM Silty GRAVEL Fraction Reigned Fines (appreclable on No. 4 Sieve amount of fines) GC Clayey GRAVEL Sand and Clean Sand SW Well -graded SAND M ore than Sandy Shcs (little or no rings) '' Sp Poorly -graded SAND 50% Retained - or more on No. Sandwith 5M Silly SAND 200 Sieve ofCoarse tC Fraction Passing Fines (approciable Size amount of rmes) SC Clayey SAND No. 4 Slave ML SILT Fine slit CL Loan CLAY Grained and Liquid Limit soils Leas than 50% clay — OrgardcSILTiOrganicCLAY OL MH FlashcSILT 50% or More Silt liquid Limit Passing and 50% or More CH Fat CLAY No. 200 Sieve Clay Size OH Organic SILTlOrganicCtAY Highly Organic Soils PT PEAT r rt COMPONENT DEFINITIONS COMPONENT SIZE RANGE Boulders Larger than 12 in Cobbles 3 in to 12 in Gravel 3 in to No 4 (A Burro) Coarse gravel 3 in to 314 In Fine gravel 314 in to No 4 (4."m) Sand No. 4 (4.5 mm) to No. 200 (0.074 mm) Coarse sand No. 4 14.5 mm) to No. 10 (20 mm) Medium sand No. 10 (2.0 mm) to No 40 (0.42 mm) Fine sand No. 40 (0,42 mm) to No. 200 (0.074 mm) Slit anr6 Clay Smarter than No. 200 (0.074mm) TEST SYMBOLS %F Percent Fines AL Atterberg Limits; PL = Plastic Limit LL = Liquid Limit CBR CaVomla Bearing Ratio CN Consolidation DO Dry Density (poQ DS Direct Shear GS Grain Size Distribution K Permeability MD MoisturelDensity Relationship (Proctor) MR Resilient Modulus PID Photalanizatlan Device Reading PP Pocket Penetrometer Approx. Compressive Strength (tsf) SG Specific Gravity TO Triaxia) Compression TV Torvane Approx. Shear Strength (tsf) VC Unconfined Compression SAMPLE TYPE SYMBOLS 2.0" OD Split Spoon (SPT) I (1401b. hammer with 30 in. drop) Shelby Tube 3-1/4'OD Split Spoon with Brass Rings 0 Small Bag Sample 2 Large Bag (Bulk) Sample nCore Run Non-standard Penetration Test (30' OD split spoon) GROUNDWATER SYMBOLS _ Groundwater Level (measured at lime of drilling) 1 Groundwater Level (measurers in well or open hole after water level stabilized) COMPONENT PROPORTIONS PROPORTION RANGE DESCRIPTIVE TERMS < 6% Clean 5 - 12% Slightly (Clayey, Silly, Sandy) 12 - 30% Clayey, Silly, Randy, Gravelly $0.50% Very (Clayey, Silly, Sandy, Gravelly) Components are arranged in order of increasing quantities. NOTES: Soil classifications presented on exploration lags are based on visual and laboratory observation. Soil descriptions are presented In the following general order: MOISTURE CONTENT DensiWconslstency, color, maditier (lfany) GROUP NAME, adul'fions to group name (if any}, molsfure DRY Absence of moisture, dusty, content. Proportion, gradation, and arDvforily of consbfuenls, additional comments. dry to the touch. (GEOLOGIC INTERPRETATION) MOIST Damp but no visible water. Please refer to the discussion in the report text as well as the exploration Visble free water. usuallyon togs for a more soA is below water sabre. Complete description of subsurface conditions. LEGEND OF TERMS AND 1 Carr Road - Panther Creek Culvert Repair SYMBOLS USED ON HWAGEOSCIENCES INC. Renton, Washington EXPLORATION LOGS PROJECT NO.; 2008-051 IGURE: A-1 LEGEND 2008051.GPJ 8f24MO DRILLING COMPANY: Holocene Drilling LOCATION: Carr Rd. 35V East of intersection with Smithers A DRILLING METHOD: Truck Mounted Hollow Stem Auger DATE STARTED: 5!9l2000 SAMPLING METHOD: Auto Hammer SPT DATE COMPLETED: 519l2006 SURFACE ELEVATION: 172 t feet LOGGED BY: J. Herrera v1 O h" � U 0 to Z) DESCRIPTION 5 10 15 1 20 9" thick layer of Asphalt GM Loose, Light olive brown, fine to coarse sandy GRAVEL with sit, moist. [FILL] Medium cobbles in cuttings below 3 feel. Loose. Light olive brown, fine to coarse sandy GRAVEL with silt, moist - Heavy caving and water seepage occuring from 7-10 feet below ground surface observed after auger casing was removed. 8M Medium dense, dark grayish brown, silly. SAND with *Mali gravels and wood bits. Upper 1.33 feet of sample is wet, below 11.3 feet, increasing silt and moisture contont. ML Very stiff, dark grayish brawn, sandy SILT with sub rounded gravel, moist. Cuttings become wet at 12.5 feet. ------------------SM - Loose, dark gray, gravelly SAND with silt, moist. Medium Dense, light olive gray, silty fine to medium BAND with ang0ar gravel, moist. Organic debris, woad bits, and pine needles present. of w Standard Penetration Test a M � 9 ¢ (140 lb. weight, 30" drop) ww ._ o A Blows per fool a a tr u.r z T � uJ cc a 0 (D 0 10 24 30 40 54 � . ir-0 N S-1 4-2-7 �j 3-2a 5-9-9 3-2b 5.9-S V8.3 3-10-11 NSA 4-5-3 HS-5 4-7-9 25J1.f.J"I I For a proper understanding of the nature of subsurface conditions, this exploration log should be read in conjunction with the text of the geotechnical report. NOTE: This log of subsurface conditions applies only at the specified location and on the date Indicated and therefore may not necessarily be indicative of other times a adlor locations, .... .. ............ . • i • A 15 ..%. I.... ..., 20 A 0 20 40 60 Bo Water Content (%) Plastic Limit Liquid Limit Natural Water Content BORING. � Carr Road -panther Creek Culvert Repair gEi-1 1 HWAGEosaENCES INC. Renton, Washington PAGE: 1 of 3 BORING 200E051.GPJ rsrzsroa PROJECT NO.: 2008-051 FIGURE: A-2 DRILLING COMPANY: Holocene Dalfing LOCATION: Carr Rd. 350' East of intersection with Smithers A DRILLING METHOD: Truck Mounted Ho}low Stern Auger DATE, STARTED: 51g12008 SAMPLING METHOD: Aulo Hammer SPT DATE COMPLETED: 51912008 SURFACE ELEVATION: 172 # feet LOGGED BY: J. Herrera [ 30 - 35 - 40 - 1 45 -1 DESCRIPTION Lu R d m a }' a w w W 7 i�g o a a a can vat 0 Very dense, medium to coarse SAND with sot, wet, L.arge IVI gravel in sample tube, sampler driven on rock. Driller notes sampler bouncing on rock. Also cuttings appear wet at 24 feet below ground surface. About 1 foot thick, very dark grayish brown, organic SILT with 5-10 mm lenses of fine sand was noted at about 25.6 feet. wet. Medium Dense, very dark grayish brown, silly SAND with smaSl to medium gravels, wet. Wood debris present. SM Medium dense, very dark brown, sty, coarse SAND, wet. [ALLUVIUM] Driller notes hard drilling at 33-34 feet below ground surface. SM Very dense, gray, silty SAND with fine sandy SILT layers, moist. [UNDIFFERENTIATED GLACIAL DEPOSITS] ........ .................. _.. Very dense, light gray, slightly fine sandy SILT with lenses of �. SM coarser SAND with sill. Driller notes variable drilling conditions from 35-40 feet Silt becoming — dark gray. _ Hard, light gray, fine sandy SILT to verydense, silty, fine ML SM SAND, moist. Gravel near bottom of sample. Lenses of clean sand through out sample, silt decreases with depth. --------- --------•--------- Very dense, light gray, silly SAND, moist. Very dense, gray, fine to coarse silty SAND with fine SM SM sub -angular gravels and medium to coarse sub rounded gravels, moist. Dri€ter notes gravely drilling from 45-50 feet, S-6 5013 S-7 1-6-8 GS S-$ 14-21-32 GS i-9a 11-20-25 F9b � 1-20-25 -10 11-5016 GS 50 - ' For a proper understanding of the nature of subsurface conditions, this exploration log should be read in conjunction with the text of the geotechnical report. NOTE: This log of subsurface conditions applies only at the specified location and on the date indicated and therefore may not necessarily be Indicative of oihor times and/or toaiions, 0 Standard Ponelration Test (140 lb. weight, 30" drop) • Blows per foot 25 ilk............. ... ..,,.... 30 +i........... .... >> 35 �: .... ... 40 AL 45 20 40 60 80 100 50 Water Content (%) Plastic Limit I --tom Liquid Limit Natural Water Content BORING: MWA Carr Road - Panther Creek Culvert Repair BH-1 HMGEoSCIwasiNC. Renton, Washington PAGE: 2 of 3 PROJECT NO.: 2008-051 FIGURE: A-2 BORING 20D805f.GPJ 6J25f s DRILLING COMPANY: Holocene Drilling LOCATION: Carr lid. 350' East of intersection with Smithers + DRILLING METHOD: Truck Mounted Hollow Stem Auger DATE STARTED: 619/2008 SAMPLING METHOD: Auto Hammer SPT DATE COMPLETED: 51912008 SURFACE ELEVATION: 172 t feet LOGGED BY: J. Herrera m U J J O o wo Vim] DESCRIPTION 1 65 — ( 1 70 — TT Very dense, light gray, line io medium slightly clayey SAND, moist. Scattered 5mm beds of darker In color, sillier material. (SANDSTONE BEDROCK) Bard, alternating light brown to gray brown, CLAY, moisl [CLAYSTONE BEDROCK] Hard, grayish brown, fine sandy CLAY, moist. Bedding structures noted below 61 feet. Fine laminations obsorved. Hard, light gray to brown fine sandy laminated C LAY, m6sl. FE Boring terminated at 70.S feet below ground surface. Heavy ground water seepage and raving observed from 7-10 feet below ground surface and saturated soils were observed at 25 to 30 feel below ground surface. Ir m �a w w a 0. 0. S 11 w O z � d w 0 F W o- 37-5015 LLI i— W w M l-- O UJ o Z O Of (5 Standard Penetration Test (140 lb. weight, 30" drop) A Slaws per foot 0 10 20 30 40 50 y F 0. O 50 S-12 27.50I6 3a 24-5016 60 t13b 24-5010 «-_-._.�,....... ..... 55 5-14 21-5015 AL 5-15 5016 • . ..... _ ._ -... 70 75J _—J 75 For a proper understanding of the nature of subsurface conditions, this 0 20 40 60 80 100 exploration log should be read in conjunction with the text of the Water Content(%) geotechnical report. Plastic Limit { —f--{ LiquWLimit Natural Wake( Content NOTE: This log of subsurface conditions applies only at the specified location and on the date indicaled and therefore may not necessarily be indicative of other times andlor €ocalions. BORING: 1 Carr Road - Panther Creek Culvert Repair BH-1 HWAGEoSaENCES INC. Renton, Washington PAGE: 3 of 3 PROJECT No.: 2008-051 FIGURE: A"2 BORING 2005051.GPJ 6125106 DRILLING COMPANY: HWA Geosciences Inc. SURFACE ELEVATION: 140.00 t feet DATE STARTED: 518i2008 l DRILLING METHOD: Hand Bucket Auger DATE COMPLETED: 5/912008 SAMPLING METHOD: GRAB LOGGED BY: (. Coltrane LOCATION: Outfall of culvert DESCRIPTION Loose, gray. gravelly SAND with cobbles and silt, wet. [ALLUVIUM] w w V o^ CL Co � ¢ dfn uj F Z c LU w vy toW © d a X z Z >w q v3 a— 0 C9 0 M A Dropwelght Cone Penetrometer (DCP) test was conducled at the exploration location to test the density of the soils, but ;jfJ no significant data was collected due to the grayally nature of the sails. is The hand hole was terminated at 1.67 feet below ground surface due to caving of the sidewalls. Ground water was encountered at 0.3 feet Betow, ground surface due to the close proximity of the stream to the exploration. a 4 S IT 0 20 40 60 80 Water Content (%) Plastic Limit Liquid Limit Natural Water Content NOTE: This log of subsurface conditions applies only at the specified location and an the date indicated and therefore may not necessarily be indicative of other times and;or locations. r-0 �-2 i-3 1--4 100 HAND HOLE: 1 Carr Road - Panther Creek Culvert Repair HH-1 HWAGEOSCIENCF,SINC Renton, Washington PAGE: 1 of 1 PROJECT NO.: 2008-051 FIGURE: A-3 HANDHOL 2008651.GPJ W25M APPENDIX B LABORATORY TESTING APPENDIX B LABORATORY TESTING HWA personnel performed laboratory tests in general accordance with appropriate ASTM test methods. Selected soil samples were tested to determine moisture content and grain -size distribution. The test procedures and results are briefly discussed below. MOISTURE CONTENT (BY MASS): The moisture contents of selected soil samples were determined in general accordance with ASTM D 2216. The results are shown graphically at the sampled intervals on the appropriate summary log in Appendix A. LIQUID LIMIT, PLASTIC LIMIT, AND PLASTICITY INDEX OF SOILS (ATTERBERG LIMITS): Selected samples were tested using method ASTM D 4318, multi -point method. The results are reported on the attached Liquid Limit, Plastic Limit, and Plasticity Index report, Figure B-l. PARTICLE SIZE ANALYSIS OF SOILS: Selected samples were tested to determine the particle size distribution of material in general accordance with ASTM D422. The results are summarized on the attached Grain Size Distribution report, Figure B-2, which also provide information regarding the classification of the sample and the moisture content at the time of testing. 60 CL CH 50 40 W Z 30 U F- 20 10 ----- -- CL-ML ML MH 0 0 20 40 60 80 100 LIQUID LIMIT (LL) SYMBOL SAMPLE DEPTH ((I) CLASSIFICATION % MC LL PL PI %Fines • BH-1 8.1A 65,0 - 66.5 (CL) Olive gray, lean CLAY 15 39 '€& 21 Carr Road - Panther Creek Culvert Repair LIQUID LIMIT, PLASTIC LIMIT AND 1 PLASTICITY INDEX OF SOILS HWAGEOSCIENCES INC Renton, Washington METHOD ASTM D4318 PROJECTMO.: 2008-051 FIGURE: B-1 HWAAi1'B 2008051 GPJ 51241p8 GRAVEL SAND E02=arse Fine Coarse Medium Fine 314" U.S. STANDARD SIEVE SIZES 3" 1-112' 5/8" 3/8" #4 #10 #20 #40 #60 #100 420C 100 I i f I f I I I so 1 I I I { I 80 1- 2 CD 70 } 60 m LLf 50 Z LL 1— 40 Z LJ U 30 ir LLJ 11 20 10 SILT CLAY 50 10 5 1 0.5 0.1 0.05 0.01 0.005 0.001 0.0005 GRAIN SIZE IN MILLIMETERS SYMBOL SAMPLE DEPTH (R) CLASSIFICATION OF SOIL- ASTM 02487 Group Symbol and Name % MC LL PL P1 Gravel Sand Fines • 13H.1 S-7 30.0 - 31.5 (SM) Very dark brawn, silty SAND 27 10.2 75.5 14.3 ■ BH-1 8.8 35.0 - 36.5 (SM) Dark gray, silty SAND 23 0.0 64.3 35.7 • BH-1 5-10 45.0 - 46.5 (SM) Dark gray, silty SAND 22 5.6 46.5 47.9 PARTICLE -SIZE ANALYSIS Carr Road - Panther Creek Culvert Repair OF SOILS HWAGEOSCIENCES INC. Renton, Washington METHOD ASTM D422 PROJECT NO.: 2008-051 FIGURE: B-2 HWAGRSZ 2608051_GPJ 012410a Garr Road -- Panther Creek Emergency Culvert Repair Project Design Memorandum City of Renton June 2008 MEMORANDUM To: Allen Quynn, Project Manager City of Renton From: Mike Giseburt, P.E. Subject: Design Memorandum Date: June 26, 2008 Background While City staff was inspecting the Panther Creek crossing of Carr Road, damage was discovered to the existing 78-inch diameter corrugated metal pipe culvert that conveys flows underneath Carr Road in south Renton. This culvert is approximately 155 feet in length and is within a deep, 25 foot fill for Carr Road. The most downstream 32 feet of culvert, which had been added to extend the culvert in 1973, was severely corroded and much of the bottom invert has rusted away. This downstream extension of the culvert had a much lighter weight structural material than the upper portion of the culvert. The joint connecting the two sections had also collapsed leaving a 3-foot by 2-foot gap within the culvert exposed to bare earth. Erosion of the exposed earth is occurring and a sink hole has developed above. The upstream portion of culvert (upstream of the damaged section) appears to be in generally good condition, with the exception of some minor corrosion and pitting along its invert. The culvert is relatively steep at a slope of 4.5% and may be a partial fish passage barrier due to high velocities and low flow depths. Although the section of culvert upstream of the separated joint does not appear to be in imminent danger of collapse, the section of pipe downstream of the failed joint could become further damaged or evert completely Dail should it experience high flows. This could result in continued sink hole development, and possible failure of the northern portion of the embankment supporting Carr Road. Failure of the embankment could result in damage to and/or closure of the sidewalk and Carr- Road. Carr Road is a major arterial for the City with high traffic volumes. In addition, there is a major water transmission line (20-inch diameter) located under the north sidewalk that could be at risk. The City has declared repair of this damaged culvert an Emergency Action and intends to repair the culvert in the summer and fall of 2008. R. W. Beck, Inc. (R. W. Beck) was retained by the City to assist in the development of project permits and construction plans and specifications of the proposed repair work. The repair work also needs to consider fish passage. The City staff has met with the WDFW Habitat Manager, who indicated that as a pant of any permit approval, an expectation would be that the repair work include modifications to provide fish passage. This memorandum provides the basis for the preliminary design of improvements. The work of this design project was established in the scope of work development between the City and R. W. Beck in May, 2008. 0011591 11-01248-10000 1 21801 Draft Feasability Analysis Memorandum06-08.doc 1001 Fourth avenue, Suite 2500 Seattle, WA 98154-1004 Phone (206) 695-4700 Fax (206) 695-4701 MEMORANDUM June 26, 2008 Page 2 Site inspection Engineers from R. W. Beck visited the site on May 15, 2008 to inspect the culvert. The culvert was observed from each end and the inside of the culvert was walked from the upstream end to the collapsed section. A topographic base map of the culvert and vicinity was created and used for this design work (Figure 1). Photographs taken during the field visit and are included in Attachment A. The culvert is 155 feet in overall length within a 25-foot high embankment. The slope is 4.5%. The culvert was constructed in two phases. The original culvert consists of 123 feet of structural plate culvert (steel plates bolted together in sections). Its shape is in the form of a vertical ellipse. Three measurements were made; 74.5" high x 67" wide (at upper end) • 72" high x 70" wide (approx. middle) • 75" high x 67.5" wide (at lower end) A standard size for this type of culvert is 76" high x 66" wide (Handbook of Steel Drainage and Highway Construction Products, 1994). Embankment loads have probably resulted in some deformation. Culvert corrugations are 2-inch high by 6-inch spacing. The structural plate culvert generally appeared to be in sound condition, although some pitting of the invert was observed, and in one location there was an approximate 2-inch by 3-inch hole in the bottom. The downstream 32-foot long section of culvert is a 78-inch diameter CMP pipe that was banded at a joint to connect to the structural plate culvert. This section of culvert, constructed about 1973 as part of a road widening project, is severally corroded along the invert with wide gaping holes. Stream flows escaping through the holes have eroded the creek channel around the outlet, such that most flow escapes through the holes rather than through the barrel of the culvert. At the joint between the upper and lower culvert sections, the lower culvert has collapsed leaving an approximate 2-foot by 3-foot section of exposed earth. The conclusions from the site inspection are that the lower section of culvert needs to be removed and the upper structural plate section is in generally good condition. However, it is recommended that some rehabilitation work be integrated into the project to prolong its life and prevent further pitting and corrosion of its invert. Such rehabilitation should be designed in conjunction with any fish passage improvements. Hydrologic and Hydraulic Analysis To assess the existing culvert capacity and consider how modifications to the culvert may affect capacity, a limited hydrologic and hydraulic analysis was performed. To estimate design flows at Carr Road, previous modeling done for another project was used. This prior study, entitled Fish Passage at Selected Panther Creek Culverts (R.W. Beck, Inc., 2006) included flow estimates at the Panther Creek crossing of Talbot Road (0.25 miles downstream of Carr Road). The flow estimates at Talbot Road were developed by Northwest 1001 Fourth Avenue, Suite 2500 Seattle, WA 98154-1004 Phone (206) 695-4700 Fax (206) 695-4701 MEMORANDUM June 26, 2008 Page 3 Hydraulic Consultants (nhc) in support of this study and were done using the HSPF model for both existing and future land use conditions. Their modeling of Panther Creek had been extracted from prior modeling of the Springbrook Creek basin which included some calibration. Estimating flows for various storm frequencies at Carr Road was simply made based on the ratio of tributary areas relative to Talbot Road. This approach is reasonable considering that the land use within the basin is generally consistent. The results are presented in Table 1. This table also provides flows that are relevant to fish passage design. The 10% duration flow for current land use conditions is 4.5 cfs, meaning that this flow is exceeded 10% of the time. WDFW criteria (2003) requires that culverts be passable for the 10% duration flow condition. Table 1 Flow Estimates of Panther Creek Area Current Land Use Future Land Use Tributary 2- 25- 100- 2- 25- 100- (acres) 50% 10% year year year 50% 10% year year year Talbot Road 1135 2.0 6.0 98 156 184 2.0 6.5 130 191 247 Carr Road 842 1.5 4.5 73 116 137 1.5 4.8 96 142 183 Notes 1) Predicted peak flows for Carr Road based on the ratio of tributary areas relative to Talbot Road. Flows of Talbot Road based on Panther Creek Fish Passage Culvert Assessment (R.W. Beck, 2OD6). 2) 50% and 1 D'10 exceedence are for Fish Passage requirements, and are the design Bow and high Now scenarios, respectively. Hydraulic capacity of the culvert was evaluated using the HY-8 computer model. The HY-8 model (developed by Federal Highway Administration) is a culvert analysis model that provides headwater depths and velocities for various flow rates that are input to the model. The HY-8 model was run for 25-year and 100-year flow rate for future land use conditions because these are the critical design events for capacity- For the model runs, the elliptical shape of the culvert was converted to a circular shape with an average dimension of 5.9 feet. The results indicate that for the existing culvert, the headwater depths would be 5.9 feet and 5.8 feet for the 25-year and 100-year future land use condition storm, respectively. The HY-8 model was also used to assess the implications of providing fish passage through the existing culvert. For this analysis it was assumed that baffles would be placed within the culvert and that the bottom of the culvert would be lined with 4 inches of concrete. This effectively adds hydraulic roughness to the culvert and also reduces its open dimension. Using a Manning's coefficient of 0.08 (believed to be conservative) and a reduced assumed diameter of 5.57 feet, the headwater depths for the 25-year and 100-year future land use conditions are 7.6 feet and 13.8 feet, respectively. For the 25-year event, this equates to a headwater depth to diameter ratio of 1.4. This meets the City's hydraulic criteria for new culverts over 18-inch diameter of having a maximum headwater depth of 1.5 times the pipe diameter for the 25-year 1001 Fourth Avenue, Suite 2500 Seattle, WA 98154-1004 Phone (206) 695-4700 Fax (206) 695-4701 MEMORANDUM June 26, 2008 Page 4 event. Thus, the existing culvert, if modified to add fish passage will have sufficient conveyance capacity for future land use conditions in the basin. Other Site Investigations Soils Investigations To provide subsurface information supporting the design project one boring was made within the Carr Road fill prism. In addition, one hand boring was also taken near the outlet of the existing culvert. The soils investigation is documented in a separate document entitled Geotechnical Study for the Carr Road Culvert Replacement Project (HWA GeoSciences, Inc., June 2008). Below the asphalt pavement, the borehole encountered about 30 feet of fill, consisting of loose to medium dense, silty sand with gravel and very stiff sandy silt, over three feet of medium dense stream deposits over very dense and hard glacial deposits and bedrock. The nature of the fill and underlying soil limits shoring options that will be necessary to excavate the approximate 20 feet of fill necessary to remove the damaged section of culvert. Constructing a shoring wail with support of tie -backs into the road embankment is not feasible because of the loose nature of the fill. Vibratory techniques, such as sheet piles are also not feasible because of the very dense soils underlying the fill and it may destabilize the road fill. As a result, the preferred approach to shoring for this project is a drilled soldier piles wall. Wetland and Stream Survey To provide environmental support information for project permits, team biologists from Herrera Environmental Consultants conducted a delineation of the creek ordinary high water both upstream and downstream of the Carr Road in the vicinity of the project. The delineation was conducted in accordance with Chapter 4-11 of the Renton Municipal Code (RMC). In addition, nearby wetlands were delineated. As required by the RMC, wetland delineations were conducted using the routine determination method outlined in the Washington State Wetlands Identification and Delineation Manual (Ecology 1997). Two wetlands were identified. One is located upstream of the culvert and one downstream. These wetlands and the ordinary high water are presented in Figure 1. Prior environmental studies were conducted by Herrera for King County as part preliminary engineering when the County was evaluating a road widening project (Carr Road Improvement Project (Herrera, September 2003)). These environmental studies provide background information on stream habitat that was useful to this culvert repair project. Because of the Emergency Declaration status of the project, this project will be exempt from SEPA. 1001 Fourth Avenue, Suite 2500 Seattle, WA 98154-1004 Phone (206) 695-4700 Fax (206) 695-4701 MEMORANDUM ,tune 26, 2008 Page 5 Culvert Repair Recommendations Alternatives Considered Several alternatives were initially considered to repair the damaged culvert. For all alternatives, it was assumed that fish passage would be required. This was based on prior input the City had received from the WDFW habitat manager. Follows is a brief listing of alternatives and some explanation of why or why not they were pursued: ■ Lining the culvert with a smaller diameter pipe or liner: Issues associated with this approach include; the collapsed section of the lower culvert would preclude pushing a smaller pipe (or liner) through the length of the culvert; existing deformations in the culvert would make it difficult for a smaller diameter pipe to fit properly, and significant reduction in capacity due to the reduced inside diameter. Therefore, this approach was not pursued. ■ Removal and replacement of the damaged section of culvert: Removal and replacement of just the damage section of culvert at matching its existing elevations would create a large drop in elevation from the culvert outlet to the existing downstream channel. This would result in a fish passage barrier and necessitate that log weirs (or similar) be employed to provide fish passage from the stream into the culvert. Because the downstream section of stream is very steep, it would require approximately 150 feet of stream channel reconstruction that would include placing fill, raising the grade of the stream and installation several log weirs (using the typical WDFW guideline of 1 ft every 10 feet). Such stream channel reconstruction was considered undesirable due to stream impacts and property acquisition. Therefore, this approach was not pursued. ■ Complete replacement of the culvert: Complete replacement of the culvert would be very costly considering the high embankment. It would also have a significant traffic impact. Additionally, it would very difficult or improbable to construct a full culvert replacement prior to this winter, which would leave the existing culvert at risk for a major failure. Therefore, this approach was not pursued. ■ Removal of the damaged section of culvert and constructing a headwall: This is the preferred alternative. It makes efficient use of the temporary shoring that would be necessary to remove the damaged culvert section by making it a permanent headwall. It has the additional benefit of making the culvert shorter and creating new stream habitat which is and environmental enhancement. Another advantage is that by opening up this portion of the culvert and replacing it with a stream channel, it can more easily transition into the existing steep section of the creek. Also, because no permanent fill is placed beyond the limits of the current culvert, permit acquisition is simplified. City staff and the Consultant team met with the WDFW habitat manager on June 4, 2008 to review the alternatives for the culvert repair. The habitat manager concurred that removal of the damaged section of culvert and constructing a headwall was the best option. He also suggested creation of the boulder cascade at the outlet. 1001 Fourth Avenue, Suite 2500 Seattle, WA 98154-1004 Phone (206) 695-4700 Fax (206) 695-4701 MEMORANDUM June 26, 2008 Page 6 Proposed Improvements The following section provides additional discussion of the recommended alternative. The proposed project improvements include two main elements; (1) complete removal of the damaged section of culvert and construction of a new headwall, and (2) installation of baffles within the undamaged section of culvert along with rehabilitating its invert. Both elements will result in long-term environmental improvement due to reducing the length of the culvert (by over 20%) and replacing this section with an open stream and by improving fish passage through the undamaged section of culvert. The following paragraphs provide additional details about the project features. A preliminary set of drawings (at 60%Q level) is included in Attachment B. New Headwall and Culvert Removal Drilled soldier piles will be used to provide shoring so that the 32 feet of damaged culvert can be removed. The piles will be installed and then timber lagging will be used to create a wall as excavation proceeds. The piles and shoring can then be used as a permanent headwall for the culvert. The alignment and height of the wall was selected to blend into the existing embankment and also open up the stream. The height of the headwall is 20 feet and the wall will extend 35 feet downstream from the outlet. A handrail will be placed at the top of the headwall for safety. There is a fairly steep drop between the existing invert of the structural plate culvert to remain and the existing creek downstream. In order to provide fish passage up to the culvert outlet, a "boulder cascade" is proposed within the limits of the new headwall to transition between the culvert outlet and the existing stream. The boulder cascade includes a mixture of large round boulders (e.g., 36-inch) placed within smaller rock to slow velocities. Natural bolder cascades can be seen in mountain streams. Anticipated methods for construction include: Clearing the area around and above the proposed headwall as well as clearing access to the headwall. This includes the removal of two large maple trees Grading a pad for a crane with a drill rig on the east side of the existing culvert Drilling and installing the soldier piles • Excavating while installing timber lagging and bracing between the piles • Creek bypass (discussed below) Removal of the existing damaged section of culvert • Excavation of material below the elevation of the culvert to allow replacement with boulders and rock Placement of formwork along the piles/timber lagging for installation of a concrete (shotcrete) headwall surfacing. 1001 Fourth Avenue, Suite 2500 Seattle, WA 99154-1004 Phone (206) 695-4700 Fax (206) 695-4701 MEMORANDUM June 26, 2008 Page 7 Placement of the boulder cascade Using long (25-foot) sections of the maple removed from the site, place 3 or 4 woody debris logs within the channel for creation of habitat and hydraulic roughness Anticipated equipment for the installation includes a large crane with a drill rig attachment, track mounted backhoe(s), concrete truck, and dump trucks. The actual methods of construction will be determined by the construction contractor retained by the City. The Contractor may alternatively choose different methods than described above_ One alternative approach would be to build a temporary pad at the existing culvert outlet large enough for a track mounded backhoe with a drill rig attachment. Any temporary work in the existing stream would be restored. Culvert Rehabilitation The undamaged section of culvert will be rehabilitated with the installation of a reinforced concrete slab in the invert and installation of baffles. The shaped concrete slab will extend 4 inches above the existing invert and is necessary to improve the structural integrity of the culvert because of the existing corrosion and pitting. Baffles will be 7.5-inches high and spaced at 7.5 feet. The size and spacing is based upon design guidelines in WDFW's 2003 Design of Road Culverts for Fish passage. Anticipated methods of construction include: Placement of temporary lighting and ventilation • Creek bypass (discussed below) • Cleaning (likely sandblasting) the existing culvert invert • Placement of reinforcement (likely including tack welds) Placement of stainless steel baffles - Concrete installation Any contaminated water by the cleaning and other activities will be collected near the outlet and pumped to a tanker for off -site all to a disposal facility. Creek Bypass A temporary creek bypass will be necessary to complete the construction. A preliminary concept for the creek bypass includes a coffer dam upstream of the culvert entrance that collects creek flow into a 24-inch pipe located within the existing 78-inch diameter pipe. The 24-inch pipe would need to be supported above the pipe invert by a few feet, perhaps using timbers wedged across the diameter of the 78-inch pipe. The City has 2 years of gaged data on Panther Creek at Talbot Road. The peak daily flows for the construction period between August and October for these two years was 10 cfs. Using the same ratio of basin areas as previously 1001 Fourth Avenue, Suite 2500 Seattle, WA 98154-1004 Phone (206) 695-4700 Fax (206) 695-4701 MEMORANDUM June 26, 2008 Page 8 discussed indicates that the peak daily flow at Carr Road would have been about 8 cfs. A 24- inch diameter pipe bypass would have a capacity of 22 cfs. Because there may be a risk of higher peak flows during the construction work window, it is recommended that there be an additional requirement in the construction contract that the contractor have available on -site sufficient material to increase the coffer dam height by up to 2 feet in an emergency situation. Other Considerations The following paragraphs provide some additional discussion of considerations as the City moves forward with design and permitting: ■ Construction Schedule: A preliminary schedule is presented in Attachment C. Because of the Emergency Declaration of the project status, the public bidding requirements will not apply. Preliminary scheduling analyses suggest that construction may extend to approximately October 15. It is recommended that the permit applications note this and approval of this window be requested from WDFW. It is also suggested that the City do whatever means necessary to reduce construction contract negotiation and execution time. ■ Encountering water within culvert during construction: Some minor wetness within the culvert during placement of the bonding agent (that forms a joint between the arch plate and the concrete) is acceptable. However, any seeps (continuous flow under some hydrostatic pressure) that are encountered will need to be either sealed or collected in a small diameter pipe to then be left in place within the new concrete. ■ Stream Design: Exact placement of the boulder cascade and woody debris should be directed on -site during construction by an engineer with experience in stream restoration. The boulder cascade must have the boulders placed in a strategic pattern and elevation to accomplish its goal of slowing down the water. Contractors have a tendency to just create a trapezoidal channel. It is recommended that the construction contract state that placement of boulders and cobbles be directed in the field by an engineer experienced in stream restoration. Attachments: A — Site Photographs B — 60% Design Plan Set C — Preliminary Project Schedule 1001 Fourth Avenue, Suite 2500 Seattle, WA 98154-1004 Phone (206) 695-4700 Fax (206) 695-4701 Attachment A SITE PHOTOGRAPHS Photo A-1. Outlet Photo A-2. Looking Up Culvert from Outlet Photo A-3, Collapsed Section of Culvert Photo A-4. Hole in Undamaged Section of Culvert. Attachment B 60% DESIGN PLAN SET F ch EL a_ VICINITY MAP NO SCALE CARR ROAD — PANTHER CREEK EMERGENCY CULVERT REPAIR PROJECT SHT NO. DWG NO 1 G1 2 G2 3 Cl 4 Q 5 C3 6 S1 7 S2 TITLE TITLE SHEET, LOCATION MAP, VICINITY MAP, AND INDEX OF DRAWINGS LEGEND, ABOREVIATO'AS, GENERAL NOTES, AND SURVEY CONTROL PLAN AND PROFILE CIVIL SECTIONS AND DETAILS TESC AND MISCELLANEOUS CIVIL DETAILS STRUCTURAL PLAN ANC SEC71ONS STRUCTURAL DETAILS ar" SL 0 60%. SUBMITTAL 6—O8 ,cs NO. REVISION OY DATE APPR uK NW1%4 SEC 32 TWN 22N R 5E PROJECT STREET ADDRESS: 9840 CARR RD SE, RENTON LOCATION MAP NO SCALE N CHECKED FOR COMPLIANCE RECOMMENDED TO CITY STANDARDS FOR APPROVAL CALL 48 HOURS BY BEFORE YOU DIG Ely BY 1-800-424-5555 AS SHOWN �„� CITY Or RENTON -�-� P3onning/BdJd,ng/�'v6iic Wcrks de pl R. CARR ROAD - PANTHER CREEK oa/coos EMERGENCY CULVERT REPAIR PROJECT TITLE SHEET, LOCATION MAP,VICINITY MAP, G i AND INDEX OF DRAWINGS LEGEND: EXISTING: PROPOSED: n. EXISTING CONTOUR (INDEX) CL CLEARING LIMITS � -- - - EXISTING CONTOUR (NOMINAL) RIGHT-OF-WAY LINES TEMPORARY CONSTRUCTION EASEMENT 20 NEW CONTOUR (INDEX) --- ROAD CENTER LINE NEW CONTOUR (NOMINAL) - PROPERTY LINE CHAIN LINK FENCE - - EASEMENT NEW UTILITY — — ORDINARY HIGH WATER (OHW) LIMITS (SAWCUT, - - -- - - -- - - - - WETLANDS BOUNDARY BOULDER CASCADE) Q KEYED NOTES WATER LINES SURVEY CONTROL POINT 10' POWER — 2' POWER — - - STEEL PIPE HANDRAIL - -- :' 12' SEWER # CONIFER TREE - - GAS LINE (IP) = INERMEDIATE PRESSURE 0 DECIDUOUS TREE SECTION LINES - LOT LINES STORM DRAIN LINES - UNDERGROUND TELEPHONE LINES - SANITARY SEWER STREET LIGHT ASSEMBLY FIRE HYDRANT CATE VALVE MONUMENT IN CASE PROJECT BENCHMARK PK NAII (CONIROL) REHAB AND CAP CULVERT STORM DRAIN CATCH 9AS;N STORM DRAIN CLEANOUT STORM DRAIN MANHOLE CONIFER TREE u $ DECIDUOUS TREE 6 SIGN z POTHOLE ? SANITARY SEWER MANHOLE i ..... UTILITY POLE WITH I IGHI - LIGHT POLE r WHEELCHAIR RAMP WETLAND FLAG Z POWER VAULT TRANSFORMER 8 8 FLAG POLE 7 TRAFFIC BOX WAFER METER 0 TELEPHONE VAULT STREET LIGHT BOX MATERIAL SYMBOLS a STREAMBED GRAVEL (SECTION) STEEL SECTION E CRUSHED SURFACING SECTION GRAVEL BACKFILL i SECTION e CONCREFE (PLAN CONTROLLED DENSITY FILL 4 OR SECTION) EXISTING CONCRETE (PLAN OR SECTION) � NEW HMA (PLAN) 1J777T/7,7 EARTH (SECTICN) NEW LIMA (sEcnaN) Q O Q 6 BOULDER CASCADE ABBREVIATIONS: AC ASBESTOS CONCRETE AP ANGLE POINT APPROX APPROXIMATE CB CATC$! BASIN CDF CONTROL'_ED DENSITY FILL CI CAST IRON CIP CAST IN PLACE �J CONSTRUCTION 'O!Nl CENTER I-INE CL CLASS, CLF CHAIN LINK FFNCF CLR CLEAR CMP CORRUGATED METAL PIPE CO CLEAN OUT COMM COMMUNICATION CONIC CONCRETE CPEP CORRUGATED POLYETHYLENE PIPE CSBC CRUSHED SURFACING BASE COURSE CSTC CRUSHED SURFACING TOP COURSE CTJ CONTROL JOINT C71R CENTER CY CUBIC YARD Di DUCTILE IRON CIA DIAMETER DWG DRAWING OWL DOWEL E EASTING, EAST EF EACH FACE EL. ELEV ELEVATION EOP EDGE OF PAVEMENT ESC EROSION AND SEDIMENT CONTROL Ew EACH WAY EX, EXIST EXISTING row FACE OF WALL CAL.V GALVANIZED HOOK HK HORIZ HORIZONTAL HPA HYDRAULIC PROJECT APPROVAL ID INSIDE DIAMETER IE INVERT ELEVATION N0. 60R SU13MITIAL K LB LF LP LT HWD MAX MIT MIC MN N NE NO NIS OC OD OHW ORN PSE PVC R RCP ROW RT S ED SDMH SE SHE Sim SS SSMH STA STD SW SWPPP TFSC TOG TYP VA VERT WDFW WSEL RLOSIGN SURVEY CONTROL PLAN SCALE: 1'-40' SEE TABLE 1. THIS DWG VERTICAL CURVE GEOMETRY VARIABLE � POUND LINEAR FEET Low roiN' LE`I LARGE WOCDY DEPRIS MAX:MIJ MANHOU MONUIENT IN, CASE MIN1MFIM NORTHING, NORTH NORTHEAST TABLE I- SURVEY CONTROL POINTS AND NUMBER NOT TO SCALE ROAD CENTERLINE ESTABLISHMENT ON CENTER OUTSIDE DIAMFTER ORDINARY HIGH WATER ORNAME.NTAI. PUGET SOUND ENERGY POLYVINYL CHLORIDE RADIUS REINFORCED CONCRETE PIPING RIGHT OF WAY RIGHT GENERAL NOTES: 1, ALL WORK AND MATERIALS SHALL BE IN ACCORDANCE WITH THE CITY OF RENTON STANDARDS AND SPECIFICATIONS AND WASHINGTON STATE DEPARTMENT OF TRANSPORTATION "STANDARD SPECIFICATIONS FOR ROAD, HRIDGE, AND MUNICIPAL CONSTRUCTION," 2005, AND AS AMENDED BY THE CITY OF RENTON SUPPLEMENTAL SPECIFICATIONS AND THE CONTRACT SPECIAL PROVISIONS. 2. ALL WORK WITHIN THE SUE SHALL BE SUBJECT TO THE INSPECTION OF THE CITY ENGINEER OR DESIGNATED REPRESENTATIVE. 3. A COPY OF THESE APPROVED PLANS AND PROJECT SPECIFICATIONS MUST BE ON THE SITE WHENEVER CONSTRUCTION 15 IN PROGRESS. 4. PRIOR TO ANY SITE CONSTRUCTION THAT INCLUDES CLEARING OR GRADING, THE SITE CONSTRUCTION LIMITS SHALL BE LOCATED AND IDENTIFIED BY THE CONTRACTOR'S PROJECT SURVEYOR AND APPROVED OF BY THE CITY- 5 TEMPORARY EROSION AND SEDIMENT CONTROL FACILITIES SHALL BE CONSTRUCTED PRIOR TO ANY GRADING OR EXTENSIVE LAND CLEARING IN ACCORDANCE WITH APPROVED TEMPORARY EROSION AND SEDIMENT CONTROL PLAN. THESE FACILITIES MUST BL SATISFACTORILY MAINTAINED UNTIL CONSTRUCTION AND LANDSCAPING IS COMPLETED AND THE POTENTIAL FOR ON -SITE EROSION HAS PASSED. 6. PUBLIC STREETS SHALL BE CLEANED ONCE PER DAY OR AS DIRECTED BY THE CITY. FLUSHING OF STREETS WITH WATER WILL NOT BE ALLOWED. 7. LOCATIONS OF EXISTING UTILITIES ARE APPROXIMATE. THE CONTRACTOR SHALL BE RESPONSIBLE FOR VERIFYING THE LOCATIONS OF THE EXISTING UTILITIES PRIOR TO CONSTRUCTION. UTILITIES SHOWN HERE ARE FOR THE PURPOSE OF ASSISTING THE CONTRACTOR IN LOCATING SAID UTILITIES. CONTRACTOR SHALL CONTACT UNDERGROUND UTILITIES LOCAFIGN CENTER (1-800-425-5555) 48 HOURS PROR TO BEGINNING OF CONSTRUCTION AND OBTAIN ON--STE UTILITY LOCATIONS- R. THE CONTRACTOR SHALL COMPLY WITH ALL OTHER NECESSARY PERMITS AND REQUIREMENTS BY THE CITY OF RENTON. SEE APPROVED PERMITS AND PERMIT REQUIREMENTS IN PROJECT SPECIAL PROVISIONS. 9, IN ACCORDANCE WITH APPROVED PERMITS, CONSTRUCTION WITHIN THE ORDINARY HIGH WATER (CHW) MARK W€II BF IIMiTFD TO THE ALLOWABLE CONSIRUCHON WINDOW AS 51All] IN THf. APPROVAQ ILI PERMIT, IG. CONIWICIOR SIIALL UL .RESPONSIBLE FOR PREPARATION OF TRAFFIC CONTROL PLANS- CONTRACTOR SHALL SUBMIT PLANS TO ENGINEER FOR APPROVAL PRIOR TO IMPLEMENTATION. POINT DESCRIPTION NORTHING j EASTING ELEV 15fi.80 A FND MON IN CASE NAIL A CONC 164381.56 1299953.45 � [ u l FNO MON IN CASE BRASS NAIL & PUNCH 164411.43 13OD334.81 174.97 C.O.R. # 1865 AA BM II39--11.4 SET PACE NAIL & WASHER 164436.27 j 130fl318-06 175,21 SLOPE HORIZONTAL DATUM: NAD 83/91 CITY OF RENTON CONTROL POINf 1855 STORM DRAIN VWRTICAL ATUM: NAVE) 88 CITY OF RENTON BENCHMARK 1865 STORM DRAIN MANHOLE ELEV.=174.97 SOUTHWAST SHEET SIMILAR SANITARY SEWER SANITARY SEWER MANHOLE STATION STANDARD SOUTHWEST STORMWATER POLLUTION PREVENTION PLAN TEMPORARY EROSION AND SEDIMENT CONTROL TOP OF GRATE TYPICAL VAULT VERTICAL WASHINGTON DEPARTMENT OF FISH AND WILDLIFE WATER SURFACE ELEVATION SECTION INDICATOR DRAWING ON WHICH SECTION IS CUT C1) A ECTION LETTER - CZ DRAWING REFERENCE NUMBER ON WHICH SECTION APPEARS DRAWING ON WHICH SECTION APPEARS (C2) DETAIL SECTION LETTER DESCRIPTION (OPTIONAL) C� SCALE: 1" - XX' DRAWING RE%ERENCE NUMBER ON WHICH SECTION IS CUT PiCE AS SHOWN AB SL oT BY DATE APPR "=' _ CITY OF PEN TON FIon g/Buuding/Public Works Dept. CALL 48 HOURS BEFORE YOU DIG 9-800-424-5555 DETAIL INDICATOR DRAWING ON WHICH DETAIL IS REFEREiJI 1 DETAIL NUMBER C2 DRAWING NUMBER ON WHICH DETAIL APPEARS DRAWING ON WHICH DETAIL APPEARS {C2) DETAIL DFTAII NUMBER DESCRIPTION (OPTIONAL) GT SCALE: i" = XX' ON WHICH REFERENCE NUMBER ON WHICH IS REFERENCED CARR ROAD - PANTHER CREEK 06/2008 EMERGENCY CULVERT REPAIR PROJECT ""°'°°` LEGEND, ABBREVIATIONS, G2 GENERAL NOTES, AND SURVEY CONTROL 1-2 7 Y ` i ~�L `H7NUItAII i BORING LOCATION a o ,.. _ ,.. ttll�llllUlif�lllgi�[. _.t PLATE CULVERT(_1_). F PLAN y SCALE: 1 "= 10' Y 5L REVISION I 5Y I OATF I APPR I -MSG HORIZ SCALE: l'-20' VERT SCALE: l'-10' GENERAL NOTES: 1. APPLY JUTE MATTING TO ALL SLOPES 2:1 AND STEEPER. 2. ELECTRONIC FILE WILL T3E PIM4L)LD FOR I CCUTION OF FINISHED GRADF CONIOUf25- 3- SLE DWG C3 IOR fVLL EXTENT OF TEuPORAR" CONSTRUCTION EASEMENTS. 4. ANY TEMPORARY FILL MATERIAL PLACED TO FACILITATE CONSTRUCTION ACCESS SHALL BE COMPLETELY REMOVED TO REESTABLISH EXISTING GRADES, EXCEPT WHERE SHOWN ON THESE DRAWINGS. 5. RESIORAIION. BOULDER CASCADE SHALL BE PLANTED WITH WILLOW STAKES AS SHOWN ON THE DRAWINGS. ALL OTHER DISTRUDED AREAS SHALL BE HYDROSEEDED. 10 5 0 10 20 Scale Feet 20 0 20 40 Scale Feel ,[As SHOWN �� w•-• CITY OF ❑nr;M -� RENTON Planning/Bu[Id-nq/Pu6ilc Works Oevi. KEYED NOTES: NSTALL 16 STAINLESS STEEL BAFFLES AND LINE AFI'ROXIMAIcly 125 llil Ol iXl5TINC CLIV1.RI INVLRI WITH CONCItf.TF- SEE SECTION A ON DWC C--2 FOR TYPICAL. SLCHON. C2) REMOVE AND DISPOSE OF APPROXIMATELY 33 FEET OF DAMAGED SECTION OF 79—INCH DIAMETER CMP PIPE. C3) NEW SOLDIER PILE WALL. SEE DRAWINGS S-1 AND S 2. O NEW HANDRAIL ON TOP OF SOLDIER PILE WALL SEE DETAIL x ON DRAWING S-2. INSTALL ROUND BOULDER CASCADE WITHIN AREA BOUND BY NEW HEADWALL. BOULDER CASCADE SHALL TRANSITION TO MATCH EXISTING GRADE AT END OF NEW HEAOWALL. SEE DETAIL 3 ON DWG C-2 FOR PLAN OF BOULDER PLACEMENT. 6 CONTRACTOR SHALL COORDINATE WITH UTILITY COMPANIES AND TEMPORARILY RELOCATE OVERHEAD POWER AND TELEPHONE TO LOT xx FOR ACCESS TO WORK AREA. CLEAR AND REMOVE TREES WITHIN LIMITS OF HEADWALL AND 26—INCH AND 35—INCH MAPLES. SALVAGE 4 25—LONG SECTION OF MAPLE TO USE AS WGQDY DEBRIS IN CHANNEL. LOCATE AND SET WOODY DEBRIS IN LOCATION SPECIFIED BY DESIGN ENGINEER (R.W. BECK). CONTRACTOR SHALL PROVIDE 2 DAYS NOTICE TO DESIGN ENGINEER PRIOR TO PLACEMENT (206-645-4608). OVERHEAD UTILITIES RUNNING EAST -WEST ALONG CARR ROAD ARE �8 NOT SHOWN FOR CLARITY. CONTRACTOR TO USE EXTREME CAUTION AROUND OVERHEAD UTILITIES. REGRADE LOCALIZED AREA OF EXISTING SLOPE TO PROVIDE / UNIFORM 51DE SLOPE BETWEEN BACK OF SIDEWALK AND NEW HEADWALL. MAX SLOPE= 1-5-1, CONTRACTOR MAY TEMPORARILY REMOVE 4' CHAIN LINK FENCE 10 FOR ACCESS. FENCE SHALL BE REPLACED WITH NEW FENCING AT NO COST TO THE OWNER. CARR ROAD - PANTHER CREEK EMERGENCY CULVERT REPAIR PROJECT PLAN AND PROFILE 06/2006 3 1` 7 ADAPTOR SKIRT, TRIM TO WITHIN RETRIEVAL STRAP 3' - 5' OF GRATE CL CL OVERFLOW BYPASS FOR PEAT( STORM VOLUMES GEOTEXTILE FABRIC SEDIMENT ACCUMULATION ND�S: 1. INSERT SHALL BE INSIALLED PRIOR TO CLEARING AND GRADING ACTTVTY, OR UPON PLACEMENT OF A NEW CATCH BASIN. 2. SEDIMENT SHALL BE REMOVED FROM THE UNIT WHEN IT BECOMES HALF FULL (12-INCItES FROM THE TOP OF THE SEDIMENT TO THE BOTTOM OF THE GRATE.) 3_ SEDIMENT REMOVAL &TALL BE ACCOMPLISHED BY REMOVING THE INSERT, EMPTYING, AND RE-INSERTING H INTO THE CATCH BASIN. DISPOSE OF SEDIMENT IN ACCORDANCE WITH LOCAL, STATE AND FEDERAL REGULATIONS. DETAIL CATCH BASIN INSERT C2 ND SCALE 36 U P CONCEPTUAL PLAN OF BOULDER PLACEMENT 3 NO SCALE \C_J 1 DETAIL 2 TEMPORARY SILT FENCE C3 NO SCALE TEMPORARY 24' CREEK BYPASS (CONTRACTOR TO DETERMINE ACTUAL LOCATION) — EXISTING STRUCTURAL PLATE CULVERT, / APPDX 75' HIGH x 68' WIDE f STAINLESS STEEL BAFFLE, PL {� TACK WELD TO EXISTING CULVERT TO HOLD IN PLACE DURING CONCRETE PLACEMENT WATERCOURSE INVERT Q CLASS 40DO CONCRETE v n L 3 3 - �n THICKNESS OF I 1 ~ ROUND BOULDERS SAND BLAST AND APPLY EPDXY BONDING AGENT TO_ 4' MIN CONCRETE CONTACT AREAS TYPICAL SECTION a PROPOSED PIPE CROSS-SECTION �1 SCALE: 1 "= I' NOTES- 1. MATERIAL EXCAVATED FOR PIPE MAY BE REUSED FOR STREAK[ COBBLES OR SANDING MIX IF SPECIFICATIONS ARE MET_ VARIES 5' TO 23' THE INTENTION IS TO CREA-E A ROUGH, NOT SMOOTH, CHANNEL. RANDOM ROCK PROTRUSIONS NEEDED TO PROMOTE CASCADING WATER WASHEO IN SAND AND GRAVEL 3 1 APPROX ---- SOLDIER POLE WALL -� TYPICAL SECTION M WATER COURSE STABILIZATION CT SCALE: I"=4' AS SHOWN y" CITY OF Aa SE - #BEN TON 0 60% SUBMITTAL 6-08 JC9 i DATJM planning/Building/Pu61ic 'Narks 0cpt. NO. REVISION BY OATF APPR- MSG -- GRADE WILLOW STAKES 1' SAND AND GRAVEL CARR ROAD - PANTHER CREEK as/zooti EMERGENCY CULVERT REPAIR PROJECT CIVIL SECTIONS AND DETAILS � C2 L CO OL Tl 0. CONSTRUCTION NOTES: TESC NOTES: CONTRACTOR TO INSTALL TEMPORARY CREEK BYPASS SYSTEM. BYPASS 1. THE IMPLEMENTATION OF THESE ESC PLANS AND THE CONSTRUCTION, MAINTENANCE, SYSTEM SHOWN ON THIS DRAWING IS SCHEMATIC AND CONTRACTOR SHALL REPLACEMENT, AND UPGRADING OF THESE FSC FACILITIES IS THE RESPONSIBILITY OF THE SUBMIT BYPASS PLAN IN ACCORDANCE WITH THE SPECIFICATIONS FOR CONTRACTOR UNTIL ALL CONSTRUCTION IS APPROVED. ' APPROVAL BY THE C3Y'. LOCALE I'VE AND COFFER DAMS TO AVOW X FOR CONSTRUCTION OF OTHER IMPROVEMENTS INCLUDING HEADWALL, 2. THE BOUNDARhES OF THE CONSTRUCTION LIMBS SHOWN ON THIS PLAN SHALL BE CLEARLY CREAKY MIT CULVERT BAFFLES. UPON COMPLETION OF FLAGGED BY THE CONTRACTOR USING YELLOW CONSTRUCTION TAPE WITH 2'X4' WOODEN STAKES CLEARING 5 BOULDER CASCADE AND \ j _ PROJECT, ALL MATERIAL USED FOR THE TEMPORARY BYPASS SHALL BE SPACED AT 20' MAXIMUM PRIOR TO CONSTRUCTION. ELECTRONIC FILES WILL BE PROVIDED TO THE ' REMOVED FROM THE SITE AND THE SITE RESTORED TO PRE -PROJECT CONTRACTOR FOR LOCATION OF THE LIMITS. DURING THE CONSTRUCTION PERIOD, NO ' CONDITIONS. DISTURBANCE BEYOND THE CONSTRUCTION LIMITS SHALL BE PERMITTED. THE CONSTRUCTION - - i r LIMBS SHALL BE MAINTAINED BY THE CONTRACTOR FOR THE DURATION OF CONSTRUCTION- LARGE ,�' .4 - Q 24' DIAMETER CREEK BYPASS PIPE SHALL WIVE SMOOTH INTERIOR WALL WOODY DEBRIS MAY BE PLACED OUTSIDE THE CONSTRUCTION LIMITS. / I AND SHALL BE MITERED AT INLET. PIPE SHALE_ BE SUPPORTED WITHIN f r EXISTING 78" CULVERT USING CONTRACTOR -DESIGNED SYSTEM. BYPASS 3- THE ESC FACILBES SHOWN ON THIS PLAN MUST BE CONSTRUCTED PRIOR T4 4R IN PIPE SHALL EXTEND FAR ENOUGH DOWNSTREAM TO ELIMINATE NEED FOR CONJUNCTION WTH ALL CLEARING AND GRADING 50 AS TO ENSURE THAT THE TRANSPORT OF A DOWNSTREAM COFFER DAM AND SHALL EXTEND FAR ENOUGH THAT SEDIMENT TO SURFACE WATERS, DRAINAGE SYSTEMS, AND ADJACENT PROPERTIES IS MINIM17ED. OUTLET ELEVATION IS A MINIMUM OF 2 VERTICAL FEET BELOW WORK 7 AREA. ELEVATION OF INLET SHALL BE 153 FT, 4- THE ESC FACILITIES SHOWN ON THIS PLAN ARE THE MINIMUM REQUIREMENTS FOR ANTICIPATED SITE CONDITIONS. DURING THE CONSTRUCTION PERIOD, THESE ESC FACILITIES SHALL BE EASEMEN, . O3 PROVIDE SAND OR GRAVEL -FILLED COFFER CAM SYSTEM TO ELEVATION UPGRADED AS NEEDED FOR CONSTRUCTION SEQUENCING AND UNEXPECTED STORM EVENTS ANO 156 FT ON UPSTREAM SIDE OF CULVERT. COFFER DAM SYSTEM TO BE SHALL BE MODIFIED TO ACCOUNT FOR CHANGING SITE CONDITIONS (E.G., ADDITIONAL SUMP \ I! CONTRACTOR -DESIGNED TO WITHSTAND ANTICIPATED HYDROSTATIC FORCES PUMPS, RELOCATION OF DITCHES AND SILT FENCES, ETC.), /f 6 I AND WITHSTANG OVERTOPPING- ` \ E 1 I 5. _THE ESC FACILITIES SHALL BE INSPECTED DAILY BY THE CONTRACTOR AND MAINTAINED TO -- f �, _ ^• / TEMPORARY DRAIN EXISTING 12 CMP AND ENSURE CONTINUED FUNCTIONING.OPER WRITTEN EKEPT OF WEEKLY C DRECTFLOW TOSTREAM SIDE OOFFERDAMREVIEWS OFF TEECACILITIES.DDAMAGED OR IROPERLYFUNCTOINGBMPS SHALL f aY j REPLACED AT NO ADDITIONAL COST TO THE CITY. INSTALL CATCH BASIN INSERTS (4) AT FIRST CS WEST AND EAST OF CULVERT SEE DETAIL 1 ON DWG C2 6. ANY AREAS OF EXPOSED SOILS THAT WILL NOT BE DISTURBED FOR TWO DAYS SHALL BE --.— '' IMMEDIATELY STABILIZED WITH THE APPROVED (SC METHODS E.G., SEEDING. MULCHING. PLASTIC EXCAVATE SUMP AT LOW POINT WHERE FLOWS EXIST EXISTING CULVERT. COVERING, ETC.). .� LINE SUMP WITH PLASTIC. DIRECT ANY CONTAMINATED CONSTRUCTION '. A NO TIME SHALL MORE THAN ONE L FOOT OF SEDI ENT B ALLOWED TO ACCUMULATE WTHIN TER SEE AGE (E.G.,(ECAFTER SAND BLASTING OPERATIONS OR CONCRETE - WA / P E I P E T I O M E f -_ ,,. .: - • i I WORK) DISCHARGING FROM CULVERT TO SUMP AND PUMP TO HOLDING A CATCH BASIN. 1HE GLEAMING OPERATION SHALL NOT FLUSH SEDIMENT LADEN WATER INTO THE DOWNSTREAM SYSTE _-_.,-- ... .. '.... .... TANK FOR OHAUL T DISPOSAL SITE PVX UPON REMOVAL OF EXISTING WN M. MPORAXY \ t DAMAGED CULVERTSECTION, RELOCATE SUMP TOCAPTURECULVERT CONSTRUCTION - SEEPAGE. 8. WHERE STRAW MULCH FOR TEMPORARY EROSION CONTROL IS REQUIRED, B SHALL BE APPLIED AT EASEMENT (TYP) - R --�2 - - F A MINIMUM THICKNESS OF 2 TO 3 INCHES, a3 i �7 INSTALL TEMPORARY SILT FENCE ACROSS CREEK BOTTOM AND AT TOP OF CHANNEL RANI ALONG CREEK. SEE DETAIL 2 ON DWG C2. AS 9. USE REINFORCED PLASTIC FABRIC TO COVER STOCKPILED ITEMS W14FN NOT IN USE THE CONSTRUCTION PROCEEDS, RELOCATE SILT FENCE WHEN NECESSARY AND REINFORCED PLASTIC FABRIC SHALL BE HELD DOWN BY A MINIMUM OF IOLB SANDBAGS PLACED AS DIRECTED BY ENGINEER, EVERY 10 FEET ALONG THE EDGE AND ACROSS THE PILE. �^ �/ \ �' 1, IN ACCORDANCE WITH TOE DEPARTMENT OF ECOLOGY REGUIREMEWIS, WASIEWAIER IRDM CEMENT CONCRETE. MASONRY, OR ASPHALT CONCRETE CUTTING OR POURING OPERATIONS SIIALL NOT BE DISCHARGED INTO STORM DRAINAGE SYSTEMS OR SURFACE wATFRS. ANY WASTAGE OR WATER GENERAL NOTES • COMING IN CONTACT WITH FRESH CQM1CRETE SHALL BE CGLLECIED IN AN IMPEFMDGS SUMP FOR COMPLETE REMOVAL AND DISPOSAL TO PREVENT CONTAMINANTS FROM ENTERING GRDUNU OR 1_ BYPASS SYSTEM IS ';IZED TO '-ASS M DL WVf IO H,AVY FALL SIDR SURFACE S. SUFFICIENT MATERIALS ON SITE TO RAISE HEIGHT OF COFFER DAM 2MFT 11. CONTRACTOR FR BASED ON 2 YEARS OF GAGED F-CW. CONTRACTOR SHALL MAINTAIN SHALL COMPLY WITH ALL APPROVED LOCAL, STATE AND Fk.UERAL REOUIf2EMENTS FOR IN CASE OF LARGE STORM EVENT. PROTECTION OF WATER QUALITY- SEE PROJECT SPECIFICATIONS FOR COPIES OF PROJECT _ '.-"'` - �_•-!..... __ - I PERMITS. A COPY OF THE APPROVED HYDRAULIC PROJECT APPROVAL (HPA) SHALL BE KEPT IN - �-- i A VISIBLE LDCATION. ALL WORK BELOW THE ORDINARY HIGH WATER LINE OHWL SHALL BE 3 WITHIN THE ALLOWABLE CONSTRUCTION WINDOW AS STATED IN THE APPROVED HPA. 12. CONTRACTOR S}IALL CAPTURE AND SAFELY REMOVE AND RELOCATE FISH WITHIN THE TEMPORARY DIVERSION AREA IN ACCORDANCE WTH THE HPA REQUIREMENTS. PRIOR TO INSTALLING TEMPORARY BYPASS, CONTRACTOR SHALL OBTAIN A WASHINGTON DEPARTMENT OF FISH AND WILDLIFE (WDFW) I SCIENTIFIC COLLECTING PERMIT PER SPEC SECTION 1-07-6 AND INSTALL FISH BLOCK NETS AND .,, NET FISH FROM WORK AREA PER PERMIT REQUIREMENTS. CONTRACTOR SHALL HAVE A OUAUnE1 BIOLOGIST CAPTURE AND SAFELY MOVE FOOD FISH, GAME FISH, AND OTHER FISH LIFE FROM THE JOB SITE. CONTRACTOR SHALL HAVE FISH CAPTURE AND TRANSPORTATION EQUIPMENT READY AND ON THE JOB SITE. CAPTURED FISH SHALL BE IMMEDIATELY AND SAFELY ` TRANSFERRED TO FREE -FLOWING WATER DOWNSTREAM OF THE PROJECT SITE. PLAN SCALE 1"-20' N 1� 20 0 20 40 Scole Feel PACE - CARR ROAD - PANTHER CREEK IX�06/2008 AR As SHOWN ° \' ' 2 CITY OF RtNTQN EMERGENCY CULVERT REPAIR PROJECT o� 5i O�TUM 0 60% SU$MITTAL 6-06 JCe Pion�;nq�a�;ie;PM�r� woks Dept. TEMPORARY EROSION AND SEDIMENT �3 NO. REVISION BY DATE APPR use x"•�° _ CONTROL AND MISCELLANEOUS CIETAILS Attachment C PRELIMINARY PROJECT SCHEDULE ID a }Task Name t Duration StaA Finish A r 6 ' 1 Apr 13 J Apr I Apr 27 kaj 4 ' May 11 May 18 1 May 25 Jun 1 Jun 8 ` Jun 15 Jun 22 Jun 29 Jd 6 '0 Jul 13 'Jul 20 ' Jul 27 ' A 3 ' A 10 A 17 A 24 A 31 S 7 ' Se 14 Se 21Se 28 Oct 5 ' Oct 12 Oct 19 1 a Notice to Proceed - Project - 1 day Fri 5/2/08 Fri 512M8 2 Fiefd Survey and Base Map - - 12 days Mon 5/5108 Tue 5120/08 3 Geotechnlcal Invesllgalions -- -- V 26 days Mon 5/5/08 Man 6l9108 4 Hydrologic and Hydraulic Analysis V - 5 days Mon SJS/o8 Fri 519J08 5 Wellanditnvironmental Investigations - f 5 days Mon 5/5/08 Fri 5/23/08 6 Select A@emalive 13 days Wed 5l21l08 Fri 6/6/08 7 - - -- - - - - — City Review - - 0 days - . _ Fri_6/6lOS_ - -Fri 6!6l08 0 8 Plans, Specifications, Estimate 36 days Mon 6l9/08 Mon 7128108 9 60 % Plans and Feasibility Memo 12 days Mon 619/08 Tue 6124/08 _ = 10 - Permit Development 4 days Wed 6/25I08 Mon 6130/08 11 90°/a Plans 20 days Tue 7/1/08 Mon 7/28/08 i2 Contractor inform selection 15 days Tue 7l1/08 Mon 7l21/08 - 13 Negotiate and Execute Construction Contract 20 days Tue 7/29/08 Mon 8125/08 14 Permit Acquisition 15 days Tue 7!1/08 Mon 7121/08 ..._ 15 _. _.. - - -- Corr lnictton NTP - - - f day - - - Tue 8126/08 -- - Tue 8/26108 16 Construction {n stream only) - -- -- - - - -- 35 days Wed 8/27/08 Tue 10/14/08 Project: Exhibit C - Preliminary Project Task r� "� _= Progress Summary EVernal Tasks _ - ) External Mirrask Date: Thu W26108 Split Milestone Project Summary - Extemal Milestone O Split Page f