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RS_Drainage_Report_190904_v2
Chateau Tower Expansion Table of Contents 1 PROJECT OVERVIEW.............................................................................................................1 Figure 1-1: Vicinity Map..........................................................................................................2 2 CONDITIONS AND REQUIREMENTS SUMMARY...................................................................3 2.1 Core Requirements...........................................................................................................3 2.1.1 Core Requirement #1: Discharge at the Natural Location ............................................3 2.1.2 Core Requirement #2: Offsite Analysis ..........................................................................3 2.1.3 Core Requirement #3: Flow Control ..............................................................................3 2.1.4 Core Requirement #4: Conveyance System...................................................................3 2.1.5 Core Requirements #5: Erosion and Sediment Control .................................................3 2.1.6 Core Requirement #6: Maintenance and Operations....................................................3 2.1.7 Core Requirement #7: Financial Guarantees and Liability .............................................3 2.1.8 Core Requirement #8: Water Quality ............................................................................3 2.1.9 Core Requirement #9: On-site BMPs .............................................................................3 2.2 Special Requirement #1: Other Adopted Area-Specific Requirements..............................5 2.2.1 Critical Drainage Areas....................................................................................................5 2.2.2 Master Drainage Plan......................................................................................................5 2.2.3 Basin Plans ......................................................................................................................5 2.2.4 Salmon Conservation Plans (SCPs) .................................................................................5 2.2.5 Stormwater Compliance Plans (SWCPs)..........................................................................5 2.2.6 Lake Management Plans (LMPs) .....................................................................................5 2.2.7 Flood Hazard Reduction Plan Updates (FHRPs) ..............................................................5 2.2.8 Shared Facility Drainage Plans (SFDPs) ...........................................................................5 2.3 Special Requirement #2: Flood Hazard Area Delineation ..................................................5 2.4 Special Requirement #3: Flood Protection Facilities ..........................................................5 2.5 Special Requirement #4: Source Controls ..........................................................................5 2.6 Special Requirement #5: Oil Control ..................................................................................5 2.7 Special Requirement #6: Aquifer Protection Area..............................................................6 3 OFFSITE ANALYSIS..................................................................................................................7 TASK 1 Study Area Definition and Maps..................................................................................7 Development Management Engineers Chateau Valley Tower i TASK 2 Resource Review ............................................................................................................7 TASK 3 Field Investigation ..........................................................................................................7 Figure 3-1: Downstream Drainage Exhibit .................................................................................8 TASK 4 Drainage System Description and Problem Description.................................................9 TASK 5 Mitigation of Existing and Potential Problems ...............................................................9 4 FLOW CONTROL AND WATER QUALITY DESIGN.....................................................................11 4.1 Pre-developed Site Hydrology ............................................................................................11 4.2 Developed Site Hydrology ..................................................................................................11 Figure 4-1: Sketch of Tributary Areas ………...............................................................................12 4.3 Performance Standards.......................................................................................................13 4.4 Flow Control System............................................................................................................14 4.5 Water Quality Calculations..................................................................................................14 5 CONVEYANCE SYSTEM ANALYSIS AND DESIGN .....................................................................15 6 SPECIAL REPORTS AND STUDIES ............................................................................................16 7 OTHER PERMITS.....................................................................................................................17 8 ESC ANALYSIS AND DESIGN....................................................................................................18 9 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT ..................19 9.1 Bond Quantities...................................................................................................................19 9.2 Facility Summaries...............................................................................................................19 9.3 Declaration of Covenant......................................................................................................19 10 OPERATIONS AND MAINTENANCE .......................................................................................20 Development Management Engineers Chateau Valley Tower ii Appendix A – Basin Information King County Parcel Report Flow Control Application Map Appendix B – Resource Review & Off-site Analysis Documentation FIRM Map Aquifer Protection Zone Erosion Hazard Map Flood Hazard Map Groundwater Protection Map Landslide Hazard Map Steep Slopes Map Coal Mine Hazard Map Appendix C – Conveyance Calculations Utilities Installation Exclusion Approval Email WWHM2012 model Results Development Management Engineers Chateau Valley Tower iii 1 PROJECT OVERVIEW The project site is located at the northeast corner of Davis Avenue South and South 45th Street and was the subject of a first phase of construction in the 2003-time frame originally titled Chateau at Valley Center. It is south of the area where the Valley Medical Center is situated in the City of Renton, King County in the northeast quarter of Section 31, Township 23 North, Range 5 East, W.M. It lies in the Black River sub-basin of the Green River drainage basin. The roadway frontages have all been improved with curb, gutter, sidewalks, landscaping and street lighting. The entire site drains generally to the north and eventually to a City 12-inch storm drain in the Davis Avenue conveyance system. The bulk of the 2.77 acre 2-lot site is occupied by the Chateau Valley Center assisted living facility constructed in the first phase about 15 years prior. The current project proposes to construct a tower expansion structure on Lot A of the RENTON Boundary Line Adjustment (BLA) LUA-11-025 Recording #20120814900003, an area of 0.57-acre. The site is bordered by commercial properties on the east, which mostly front Talbot Road. Across Davis Avenue is a parking lot associated with the Valley Medical center. The King County tax parcel ID number for Lot A is shown in Table 1 below (refer to the King County Parcel Report included in Appendix A). Table 1: Parcel Information KC Parcel # Site Address Site Area (SF) 6391800125 4320 Davis Avenue S 25,104 The current project site, Lot A an area of 0.57 acres contains a portion of the existing surface parking, storm drainage facilities and other utilities constructed as part of Phase 1. There is also an informal gravel parking lot at the northerly portion of the site. There is minimal upstream flow from the improved areas to the east of the site. Those flows were previously analyzed in the Phase 1, (2003) TIR. As noted above, a portion of the 2003-05 Phase 1 improvements were constructed within Lot A including surface parking and a portion of the Phase 1 storm drains and stormwater wet vault. The proposed Phase 2 development of the property, Chateau Valley Tower will include a 2-level parking garage with a below-grade level and entrance grade level parking. Additional assisted living units are to be located on the upper floors. New driveways and utilities will be installed along with a new stormwater detention vault and storm drain system. Frontage improvements include a pair of driveways to serve as access ramps to the parking garage and exits for the existing surface parking and proposed drop-off area. Most of the Phase 1 improvements located in Lot A will remain in place but be impacted with the installation of the new storm detention vault and utilities. With the proposed new stormwater detention vault construction extending into Lot B Phase 1 surface parking, approximately 0.022 acres will also be impacted. The project will be designed using the guidelines and requirements established in the 2017 City of Renton Surface Water Design Manual (2017 RSWDM). The project is exempt from Basic Water Quality treatment since the Pollution Generating Impervious Surfaces (PGIS) is less than 5000 SF. The drainage analysis for the site was completed using WWHM2012. See Figure 1-1 Vicinity Map for project location. Development Management Engineers Chateau Tower Expansion Page 1 Figure 1-1: Vicinity Map Information Technology - GIS RentonMapSupport@Rentonwa.gov This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. 1/9/2019 THIS MAP IS NOT TO BE USED FOR NAVIGATION Development Management Engineers Chateau Valley Tower Page 2 PROJECT SITE 2 CONDITIONS AND REQUIREMENTS SUMMARY The proposed project is classified as requiring “Full Drainage Review” per the 2017 RSWDM. Therefore, all eight core requirements and five special requirements will be addressed per Section 1.1 of the 2017 RSWDM. 2.1 Core Requirements 2.1.1 Core Requirement #1: Discharge at the Natural Location The project will maintain the natural discharge location on the west side of the parcel to the storm drain system in Davis Avenue S. 2.1.2 Core Requirement #2: Offsite Analysis This core requirement is addressed in Section 3 of this report. 2.1.3 Core Requirement #3: Flow Control A detention vault is required for flow control for this development. The vault is designed to match the forested condition or Conservation Flow Control. This requires that the developed condition discharge durations match the existing condition durations from 50% of the 2-year to the 50-year storm events and that the developed 2-year and 10-year peak discharge rates do not exceed the existing 2-year and 10-year peak discharge rates, respectively. Refer to Section 4 for the analysis and results. 2.1.4 Core Requirement #4: Conveyance System A backwater analysis using King County Backwater (KCBW) will be provided in Section 5 to show that the proposed conveyance system provides sufficient capacity for the 25-year storm as calculated by the Rational Method. 2.1.5 Core Requirements #5: Erosion and Sediment Control Erosion and sediment control will be provided through catch basin protection, interceptor swales, rock check dams, silt fencing and a construction access entrance. Since the construction will involve excavating below grade for the lower garage level, dewatering may be required at early stages of construction. Portable construction stormwater tanks, (Baker Tanks) may be specified, if required. 2.1.6 Core Requirement #6: Maintenance and Operations The owner will be responsible for the maintenance and operations of the private stormwater facilities located on the site. An Operations and Maintenance Manual will be provided in Section 10. 2.1.7 Core Requirement #7: Financial Guarantees and Liability A bond quantities worksheet will be provided in Section 9. 2.1.8 Core Requirement #8: Water Quality The project does not add more than 5,000 square feet of new or replaced pollution generating impervious surface. Therefore, Water quality treatment will not be provided. 2.1.9 Core Requirement #9: On-Site BMPs On-Site BMPs have been evaluated for the project per section 1.2.9 of the 2017 Renton SWDM. Development Management Engineers Chateau Valley Tower Page 3 If the proposed project is on a site/lot larger than 22,000 square feet, then on-site BMPs must be applied as specified in the requirements below or the project must demonstrate compliance with the LID Performance Standard (described in Section 1.2.9.1.B) using an approved continuous runoff model. This project is not in compliance with the LID performance standard and has been evaluated for the following BMPs in order of precedence: 1. Full Dispersion must be evaluated for all target impervious surfaces. Site constraints cannot accommodate the required flow path of 100 feet of native vegetation for full dispersion. 2. Where Full Dispersion is not feasible for target impervious roof areas, full infiltration of roof runoff must be implemented if feasible. Full infiltration is not feasible on the project site. Per the geotechnical report prepared by Associated Earth Sciences, see reference Section 6, the soil type is comprised of variable glacial till. In addition, groundwater seepage was found in depths ranging from 2 feet to 7 feet below surface. This soil type is typically not recommended for use as an infiltration receptor. 3. All target surfaces not mitigated by requirements 1 and 2 above, must be mitigated to the maximum extent feasible using one or more of the BMPs from the following list: Full Infiltration, Limited Infiltration, and Bioretention are infeasible. Per the geotechnical report by Associated Earth Sciences, the soil type is comprised of variable glacial till and there is groundwater seepage present. In general, variable till soils have limited capacity for infiltration as a means of handling stormwater. • Bioretention is not feasible due to space and site constraints. • Permeable Pavement is also infeasible. Variable glacial till soils and the presence of groundwater indicate a limited capacity for infiltration. 4. All target surfaces not mitigated by requirements 1, 2 and 3 above, must be mitigated to the maximum extent feasible using basic dispersion. Basic dispersion is not proposed since site and grading constraints cannot accommodate the required 25-foot vegetated flow path. 5. Implementation BMP’s for impervious areas of the site coverage greater than 65% on the buildable portion of the site must be applied to 20% of the target surface or at least 10% of the site, whichever is less. Use of Reduced Impervious Surface Credit, Native Growth Protection Credit, or Tree Retention Credit is not feasible on this site because of site constraints. 6. The soil moisture holding capacity of new pervious surfaces (target pervious surfaces) must be protected in accordance with the soil amendment BMP as detailed in Appendix C, Section C.2.13. The areas proposed for site landscaping will call for use of amended soils BMP. 7. Installation of perforated pipe connection is not considered feasible at this location due to the glacial till nature of the site native soils. Development Management Engineers Chateau Valley Tower Page 4 2.2 Special Requirement #1: Other Adopted Area-Specific Requirements 2.2.1 Critical Drainage Areas Per the City’s Aquifer Protection Zone map, the project is not in an aquifer protection zone. A copy of the COR aquifer protection and wellhead protection zone map is included in Appendix B. 2.2.2 Master Drainage Plan Not applicable. 2.2.3 Basin Plans There are no basin plans for this project. 2.2.4 Salmon Conservation Plans (SCPs) There is no salmon conservation plan for this project. 2.2.5 Stormwater Compliance Plans (SWCPs) Not applicable. 2.2.6 Lake Management Plans (LMPs) Not applicable. 2.2.7 Flood Hazard Reduction Plan Updates (FHRPs) This project is not within a floodplain (see FEMA map included in Appendix B) and is not within an area with an applicable Flood Hazard Reduction Plan. Therefore, additional requirements from a Flood Hazard Reduction Plan do not apply. 2.2.8 Shared Facility Drainage Plans (SFDPs) Not applicable. 2.3 Special Requirement #2: Flood Hazard Area Delineation This project is not located within the 100-year floodplain (see FEMA Map included in Appendix B). 2.4 Special Requirement #3: Flood Protection Facilities As this project is not located within a 100-year floodplain there are no levees, revetments or berms within the project. 2.5 Special Requirement #4: Source Control These requirements are only applicable as the project is to the extent that there will be food preparation on the site. A list of typical controls are included as a part of the M&O plan for the site. A grease trap will be provided and the lower level parking structure will have floor drains routed to the sanitary sewer. 2.6 Special Requirement #5: Oil Control This requirement does not apply because the project is not expected to have more than 15,000 vehicles per day. Development Management Engineers Chateau Valley Tower Page 5 2.7 Special Requirement #6: Aquifer Protection Area Aquifer Protection Area(s) (APA) are identified in the RMC 4-3-050. If a proposed project is located within the APA, this special requirement requires the project to determine those components that are applicable and delineate them on the project’s site improvements plans. Reference Section 15-B includes a map of the City’s Aquifer Protection Area, Zones 1 and 2. The proposed project is not located in either APA Zone, therefore no special measures are applicable, see Appendix B for the Aquifer Zone Protection Map. Development Management Engineers Chateau Valley Tower Page 6 3 OFFSITE ANALYSIS TASK 1 Study Area Definition and Maps The proposed project contains parcel number 6391800125. A map of the downstream drainage systems can be found in Figure 3-1 Downstream Drainage Exhibit. TASK 2 Resource Review Basin Reconnaissance Summary Reports: No Basin Reconnaissance Summary Reports appear to be available for the area that is within one mile of this project site. FEMA Maps: Per the City’s Effective FEMA Flood Insurance Rate Map, the project site is not in the 100-year floodplain. The FEMA Map is included in Appendix B. Sensitive Areas Folio: Per the City of Renton Sensitive Areas Maps, this project has some steeper slopes peripherally located along the east property lines; however, these have been negated by construction of retaining walls in Phase 1 or with this project. Soils The Geotechnical Report was completed by Earth Consultants, Inc. in January 2002. The site soils were found to include varying depths of medium dense, silty, fine to medium grained sand with gravel (SM) or silty-sand to sandy silt (ML) up to the ten feet depth of the test pits. Groundwater seepage typically occurred between 2 to 7 feet deep. Downstream Drainage Complaints Drainage complaints were researched within the study area. King County lists no complaints within a quarter mile of the downstream discharge point. See the Figure 3-1 Downstream Drainage Map in the next section. Restrictive Well Covenant There is no existing well onsite. TASK 3 Field Investigation Upstream Tributary Area There is minimal upstream drainage area from fully developed parcels to the east. Downstream Analysis The site drains northwest to existing catch basins located in the curbed street section of Davis Avenue S just south of SW 43rd Street. A 12-inch storm pipe heads north and turns west to a 24-inch storm culvert under SW 43rd Street where it enters the private system in the Valley Medical Center which continues north in a 27-inch pipe for several hundred feet before daylighting to the northwest through an undeveloped parcel in a drainage course adjacent to SR-167. The state highway system then conveys these flows before eventually discharging into Springbrook Creek. Development Management Engineers Chateau Valley Tower Page 7 9,028 752 City of Renton Print map Template This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. Storm water system 7/3/2019 Legend 5120 256 THIS MAP IS NOT TO BE USED FOR NAVIGATION Feet Notes 512 WGS_1984_Web_Mercator_Auxiliary_Sphere Information Technology - GIS RentonMapSupport@Rentonwa.gov City and County Labels City and County Boundary Parcels Pump Stations Discharge Points Stormwater Mains Culverts Open Drains Facility Outlines Private Pump Stations Private Discharge Points Private Pipes Private Culverts Private Open Drains Private Facility Outlines Drainage Complaints Known Drainage Issues Renton King County Streets Parks Waterbodies Map Extent2010 FIGURE 3.1 DOWNSTREAM DRAINAGE TASK 4 Drainage System Description and Problem Description The Drainage Complaints Map in the COR GIS did not reveal any drainage complaint requests. See the Figure 3.1 above. TASK 5 Mitigation of Existing and Potential Problems Downstream Drainage Problems Requiring Special Attention Type 1 – Conveyance System Nuisance Problems There are no known, reported or observed current downstream conveyance nuisance problems. Type 2 – Severe Erosion Problems There are no known, reported or observed current downstream severe erosion problems. Type 3-Severe Flooding Problems There are no known, reported or observed current downstream severe flooding problems. Downstream Water Quality Problems Requiring Special Attention Type 1 – Bacteria Problems There are no known or reported downstream bacteria problems. Type 2 – Dissolved Oxygen (DO) Problems There are no known or reported downstream dissolved oxygen problems. Type 3 – Temperature Problems Springbrook Creek has a seasonal temperature problem. Due to the distance from the project site and the highly developed urban nature of this drainage area, there are no special provisions that can address this issue for this project. See listing information on the next page. Type 4 – Metals Problems There are no known or reported downstream metals problems. Type 5 – Phosphorous Problems There are no known or reported downstream phosphorous problems. Type 6 – Turbidity Problems There are no known or reported downstream turbidity problems. Type 7 – High pH Problems There are no known or reported downstream high pH problems. Bioassessment Springbrook Creek is a Category 2 for bioassessment. Drainage Adjustments There are no proposed drainage adjustments. Development Management Engineers Chateau Valley Tower Page 9 Receiving Water characteristics • WTR_NAME Springbrook Creek • WRIA_NO 9 • WRIA_NAME Duwamish-Green • WTRSHD_ID 902 • WTRSHD_NAME Duwamish - Green River • BASIN_ID 90201 • BASIN_NAME Black River • RTE_ID 090201010100000000 • STR_LVL 2 • SOURCE_NAME 2012 Aerial Photo • Water Feature Type Stream • Type Classification S – Shoreline Parameter: Temperature Medium: Water Listing ID: 72608(view listing) Assessment Unit ID: 17110013008361 Waterbody Name: Springbrook (Mill) Creek Development Management Engineers Chateau Valley Tower Page 10 4 FLOW CONTROL AND WATER QUALITY DESIGN 4.1 Pre-developed Site Hydrology The disturbed area includes the new development in Lot A plus construction of a new stormwater detention vault and outlet pipe, relocation of the existing Phase 1 storm drain to accommodate the new vault and installation of other utilities within the existing surface parking lot spanning both Lots A and B, see Figure 4.1 Tributary Areas Map. Per RSWDM 2017, Definitions, Page 1-7, the construction areas of the detention vault and new utilities are excluded from consideration as Replaced Impervious Surface because the impervious surfaces are being removed for the sole purpose of installing Utilities. See email confirmation from Renton in Appendix C. The total disturbed area for the Phase 2 development is approximately 0.451 acres. The existing site has asphalt surface parking and informal gravel parking lots occupying most of the site fronting Davis Ave. There are some trees on the east side of the property with an existing slope running in the north-south direction close to the east lot line. The site drains to the northwest at slopes ranging between 3 and 7 percent and locally steeper at the east property line. Pre-developed Conditions Areas GROUND COVER AREA (acres) Till-Forest 0.451 TOTAL = 0.451 Pre-developed Peak Flows Pre-developed Scenario from WWHM2012 model and peak flow rates: ___________________________________________________________________ Flow Frequency Return Periods for Pre-developed conditions. Return Period Flow (cafes) 2 year 0.013266 5 year 0.020834 10 year 0.025123 25 year 0.029668 50 year 0.032479 100 year 0.034871 4.2 Developed Site Hydrology In the developed condition, the site will continue to drain to the northwest. The roof of the new tower expansion as well as surface runoff from the east slope and a portion of the drop-off area are the main areas that can reasonably be captured for flow control. The remaining areas either slope to Davis Avenue or back to the lower level parking garage and are therefore are bypassed and unable to be captured and are bypassed. However, the flows were computed and routed to a point of compliance. See Figure 4.1 for sketch of tributary areas. Development Management Engineers Chateau Valley Tower Page 11 GROUND LEVEL PARKING FF=105.8' 10 2 10 3 10 4 10 5 99 98 112 RESTRIPE TO REMOVE THREE EXIST. PARKING SPACES PER ARCHITECTURAL PLANS. NEW VAULT FOR TOWER EXPANSION 30' x 39' x 6' ACTIVE STORAGE FIGURE 4.1 SKETCH OF TRIBUTARY AREAS Developed Conditions Areas ___________________________________________________________________ Pervious Land Use Acres C, Pasture, Mod 0.098 Impervious Land Use Acres ROOF TOPS FLAT 0.281 DRIVEWAYS FLAT 0.045 DRIVEWAYS MOD 0.012 DRIVEWAYS STEEP 0.013 SIDEWALKS FLAT 0.002 Impervious SubTotal 0.353 TOTAL 0.451 Developed Peak Flows The Developed scenario from WWHM2012 using a detention vault 30’x39’x7’ with an active storage depth of 6’ is shown below: ___________________________________________________________________ Flow Frequency Return Periods for Developed. POC #1 Return Period Flow (cfs) 2 year 0.008865 5 year 0.013912 10 year 0.01796 25 year 0.023947 50 year 0.029086 100 year 0.034847 4.3 Performance Standards All stormwater facilities will be designed in accordance with the 2017 RSWDM with Conservation Flow Control Standards. A water quality treatment system will not be required as the runoff from roof areas which is most of the anticipated flows, is considered clean water. Flow Control: Conservation Flow Control Standard The Conservation Flow Control Standard requires maintaining the durations of high flows at their pre- development levels for all flows greater than one-half of the 2-year peak flow through the 50-year peak flow. The pre-development peak flow rates for the 2-year and 10-year runoff events must also be maintained under this requirement. Conveyance Capacity: The proposed conveyance system will be designed with sufficient capacity to convey and contain the 25- year peak flow as determined by the Rational Method. It will also be verified that the 100-year peak flow will not create or aggravate a severe flooding or erosion problem per Section 1.2.2. Water Quality: Basic Water Quality Menu This project will add less than 5,000 square feet of pollution generating Impervious surface (PGIS) so no water quality treatment is required. Development Management Engineers Chateau Valley Tower Page 13 4.4 Flow Control System Calculation of Effective Impervious Area The impervious area for the site applied to the developed basin time series file was determined using the criteria in the 2017 RSWDM page 3-24 for commercial zones. The proposed development is urban assisted residential. The site is zoned Commercial Office (CO) (see parcel information in Appendix A). For Commercial zones there is no minimum or maximum impervious area per site per the 2017 RSWDM; rather the impervious surfaces are to be “estimated from layouts of the proposal”. Small Lot BMP Requirements If the proposed project is on a site/lot smaller than 22,000 square feet, then flow control BMPs must be applied as specified in the requirements below or the project must demonstrate compliance with the LID Performance Standard (described in Section 1.2.9.1.B, p. 1-83) using an approved continuous runoff model. This project is not in subject to this LID performance standard as it is larger than the threshold. Small Road Improvement and Urban Road Improvement Projects BMP Requirements If the proposed project is a road improvement project that is within the UGA or is on a site/parcel less than five acres in size, then flow control BMPs must be applied as specified in the requirements below: This project is not subject to this LID performance standard as it is not a road improvement project. Flow Control A stormwater detention vault is proposed for this development. The collected roof area flows, yard drains and catch basins serving the drop-off area will discharge to the proposed vault. The outflow will connect to the existing wet vault outlet pipe which discharges to the public storm system in Davis Avenue S. The full WWHM2012 report has been included in Appendix C. 4.5 Water Quality Calculations The project is adding approximately 3,000 square feet of pollution generating impervious area (PGIS) which is less than 5,000 square feet so water quality treatment is not required. Table 4-3 PGIS Area GROUND COVER AREA (SF) Driveway Approaches 520 Driveways (estimated) 2,480 TOTAL 3,000 Development Management Engineers Chateau Valley Tower Page 14 5 CONVEYANCE SYSTEM ANALYSIS AND DESIGN Analysis of the onsite conveyance system will be provided during the construction permit application phase of the project. Development Management Engineers Chateau Valley Tower Page 15 6 SPECIAL REPORTS AND STUDIES Geotechnical Report Earth Consultants, Inc. 1805 136th Place Northeast, suite 102 Bellevue, WA 98005 Prepared by: Raymond Cola’s, P.E. Dated: January 16, 2002 Plus, Supplement Letter dated June 20, 2019 Development Management Engineers Chateau Valley Tower Page 16 7 OTHER PERMITS ➢ Construction Permit ➢ Building Permits ➢ ROW Use Permit ➢ NPDES Permit Development Management Engineers Chateau Valley Tower Page 17 8 ESC ANALYSIS AND DESIGN The site will utilize Appendix D of the 2017 RSWDM for the erosion and sedimentation control design to reduce the discharge of sediment-laden runoff from the site. Clearing limits will be established prior to any earthwork on the project site. Perimeter protection will be provided by silt fencing to limit the downstream transport of sediment to neighboring properties. A temporary construction entrance or wheel wash will be used to reduce the amount of sediment transported onto paved roads by construction vehicles and, if required dust control will be provided by a water truck. Development Management Engineers Chateau Valley Tower Page 18 9 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 9.1 Bond Quantities A Site Improvement Bond Quantity Worksheet to be provided with the construction Permit Application. 9.2 Facility Summaries A facility summary sheet will be provided with the submittal of the final plans. 9.3 Declaration of Covenant Not applicable. Development Management Engineers Chateau Valley Tower Page 19 10 OPERATIONS AND MAINTENANCE The operations and maintenance information follows this Section. The document includes a selection of portions from Appendix A of the 2017 RSWDM and Construction Permit plan set. Development Management Engineers Chateau Valley Tower Page 20 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Tank or Vault Storage Area Trash and debris Any trash and debris accumulated in vault or tank (includes floatables and non- floatables). No trash or debris in vault. Sediment accumulation Accumulated sediment depth exceeds 10% of the diameter of the storage area for ½ length of storage vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than ½ length of tank. All sediment removed from storage area. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipes Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Development Management Engineers Chateau Valley Tower Page 21 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole (cont.) Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. Development Management Engineers Chateau Valley Tower Page 22 #5 – MAINTENANCE CHECKLIST FOR CATCH BASINS: MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment . Trash and Debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within the catch basin. Deposits of garbage exceeding 1 cubic foot in volume. Inlet and outlet pipes free of trash or debris. Damage to Frame and/or Top Slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than one-fourth inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than three-fourth inch of the frame from the top slab. Frame not securely attached. Frame is sitting flush on the top slab. Cracks in Basin Walls or Bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that structure is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ Misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash and debris in pipes Development Management Engineers Chateau Valley Tower Page 23 #5 – MAINTENANCE CHECKLIST FOR CATCH BASINS: (cont.) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/outlet pipe (cont.) Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and Debris Trash and debris that is blocking more than 20 percent of grate surface inletting capacity. Cover is missing or only partially in place. Any open catch basin requires maintenance. Grate free of trash and debris. footnote to guidelines for disposal Damaged or Missing grate Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover Not in Place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking Mechanism Not Working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover Difficult to Remove One maintenance person cannot remove lid after applying 80 lbs. of lift. Cover can be removed and reinstalled by one maintenance person. If you are unsure whether a problem exists, contact a professional engineer. Development Management Engineers Chateau Valley Tower Page 24 NO. 6 – CONVEYANCE PIPES AND DITCHES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/root growth in pipe Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged pipes Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive vegetation growth Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Rock lining out of place or missing (If applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. Development Management Engineers Chateau Valley Tower Page 25 NO. 11 – GROUNDS (LANDSCAPING) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash & debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible. No hazard trees in facility. Damaged tree or shrub identified Limbs or parts of trees or shrubs that are split or broken which affect more than 25% of the total foliage of the tree or shrub. Trees and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation. Trees or shrubs free of injury. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub in place and adequately supported; dead or diseased trees removed. Development Management Engineers Chateau Valley Tower Page 26 NO. 38 – SOIL AMENDMENT BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Soil Media Unhealthy vegetation Vegetation not fully covering ground surface or vegetation health is poor. Yellowing: possible Nitrogen (N) deficiency. Poor growth: possible Phosphorous (P) deficiency. Poor flowering, spotting or curled leaves, or weak roots or stems: possible Potassium (K) deficiency. Plants are healthy and appropriate for site conditions Inadequate soil nutrients and structure In the fall, return leaf fall and shredded woody materials from the landscape to the site when possible Soil providing plant nutrients and structure Excessive vegetation growth Grass becomes excessively tall (greater than 10 inches); nuisance weeds and other vegetation start to take over. Healthy turf- “grasscycle” (mulch-mow or leave the clippings) to build turf health Weeds Preventive maintenance Avoid use of pesticides (bug and weed killers), like “weed & feed,” which damage the soil Fertilizer needed Where fertilization is needed (mainly turf and annual flower beds), a moderate fertilization program should be used which relies on compost, natural fertilizers or slow-release synthetic balanced fertilizers Integrated Pest Management (IPM) protocols for fertilization followed Bare spots Bare spots on soil No bare spots, area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction • To remediate compaction, aerate soil, till to at least 8-inch depth, or further amend soil with compost and re-till • If areas are turf, aerate compacted areas and top dress them with 1/4 to 1/2 inch of compost to renovate them • If drainage is still slow, consider investigating alternative causes (e.g., high wet season groundwater levels, low permeability soils) • Also consider site use and protection from compacting activities No soil compaction Poor infiltration Soils become waterlogged, do not appear to be infiltrating. Facility infiltrating properly Erosion/Scouring Erosion Areas of potential erosion are visible Causes of erosion (e.g., concentrate flow entering area, channelization of runoff) identified and damaged area stabilized (regrade, rock, vegetation, erosion control matting).For deep channels or cuts (over 3 inches in ponding depth), temporary erosion control measures in place until permanent repairs can be made Grass/Vegetation Unhealthy vegetation Less than 75% of planted vegetation is healthy with a generally good appearance. Healthy vegetation. Unhealthy plants removed/replaced. Appropriate vegetation planted in terms of exposure, soil and soil moisture. Noxious Weeds Noxious weeds Listed noxious vegetation is present (refer to current County noxious weed list). No noxious weeds present. Appendix A Fair, Equitable, and Understandable Property Valuations 6/30/2019 King County Department of Assessments: eReal Property https://blue.kingcounty.com/Assessor/eRealProperty/Detail.aspx?ParcelNbr=6391800125 1/3 ADVERTISEMENT New Search Property Tax Bill Map This Property Glossary of Terms Area Report Print Property Detail PARCEL DATA Parcel 639180-0125 Name PUBLIC HOSP DISTR#1 KING CO Site Address 4320 DAVIS AVE S 98055 Geo Area 75-65 Spec Area 153-320 Property Name Chateau at Valley Center Jurisdiction RENTON Levy Code 2100 Property Type C Plat Block / Building Number Plat Lot / Unit Number 10-12 Quarter-Section-Township- Range NE-31-23-5 Legal Description ONE VALLEY PLACE LOT A RENTON BLA LUA-11-025-LLA REC #20120814900003 SD BLA LOTS 10-12 OF SD PLAT PLat Block: Plat Lot: 10-12 LAND DATA Highest & Best Use As If Vacant COMMERCIAL SERVICE Highest & Best Use As Improved PRESENT USE Present Use Retirement Facility Land SqFt 25,104 Acres 0.58 Percentage Unusable Unbuildable NO Restrictive Size Shape NO Zoning CO Water WATER DISTRICT Sewer/Septic PUBLIC Road Access PUBLIC Parking ADEQUATE Street Surface PAVED Views Waterfront Rainier Territorial Olympics Cascades Seattle Skyline Puget Sound Lake Washington Lake Sammamish Lake/River/Creek Other View Waterfront Location Waterfront Footage 0 Lot Depth Factor 0 Waterfront Bank Tide/Shore Waterfront Restricted Access Waterfront Access Rights YES Poor Quality NO Proximity Influence NO ADVERTISEMENT Reference Links King County Tax Links Property Tax Advis Washington State Department of Revenue (External link) Washington State Board of Tax Appeals (External link) Board of Appeals/Equalizatio Districts Report iMap Recorder's Office Scanned images of surveys and other map documents Scanned images of plats Additional fees apply. Rate excludes taxes. Speed may not be available in your area. Rate requires paperless billing. Maximum download/upload speed of up to 940 Mbps via a wired connection.Details Bring on the fireworks! Save on select destinations worldwide until July 4. 4 OF JULYSALE th APPENDIX A 6/30/2019 King County Department of Assessments: eReal Property https://blue.kingcounty.com/Assessor/eRealProperty/Detail.aspx?ParcelNbr=6391800125 2/3 Designations Nuisances Historic Site Current Use (none) Nbr Bldg Sites Adjacent to Golf Fairway NO Adjacent to Greenbelt NO Other Designation NO Deed Restrictions NO Development Rights Purchased NO Easements NO Native Growth Protection Easement NO DNR Lease NO Topography Traffic Noise Airport Noise Power Lines NO Other Nuisances NO Problems Water Problems NO Transportation Concurrency NO Other Problems NO Environmental Environmental NO BUILDING TAX ROLL HISTORY This is a government owned parcel. Change to state law (RCW 84. 40.045 and 84.40.175) by the 2013 Legislature eliminated revaluation of government owned parcels. SALES HISTORY REVIEW HISTORY PERMIT HISTORY HOME IMPROVEMENT EXEMPTION New Search Property Tax Bill Map This Property Glossary of Terms Area Report Print Property Detail ADVERTISEMENT Appendix B Effective FEMA Flood Insurance Rate Map Appendix C Utilities Installation Exclusion Approval Email PRE 18-000-370 Site Plan Pre-Screening Meeting - Chateau Valley Expansion From: Rohini Nair <RNair@Rentonwa.gov> Sent: Friday, June 14, 2019 6:49 PM To: 'Cliff Williams' <cliff@sitedme.com> Cc: 'Joe Carlson' <joe.carlson@chateaullc.com>; 'Jim Godfrey' <Jim.Godfrey@Chateaullc.com>; Clark Close <CClose@Rentonwa.gov>; 'Chris Beckman' <bmwjupiter@gmail.com> Subject: RE: PRE 18-000-370 Site Plan Pre-Screening Meeting - Chateau Valley Expansion Hi Cliff, Only the surface that will be excavated for the sole purpose of installation of the detention vault utility can be considered for the exclusion of replaced impervious surface. Sincerely Rohini Rohini Nair, P.E. Civil Engineer III | Dev. Eng. | CED City of Renton 1055 S. Grady Way, Renton, WA 98057 rnair@rentonwa.gov | Phone: (425) 430-7298 From: Cliff Williams [mailto:cliff@sitedme.com] Sent: Tuesday, June 11, 2019 10:04 AM To: Rohini Nair <RNair@Rentonwa.gov> Cc: 'Joe Carlson' <joe.carlson@chateaullc.com>; 'Jim Godfrey' <Jim.Godfrey@Chateaullc.com>; Clark Close <CClose@Rentonwa.gov>; 'Chris Beckman' <bmwjupiter@gmail.com> Subject: PRE 18-000-370 Site Plan Pre-Screening Meeting - Chateau Valley Expansion Rohini: Regarding the Stormwater comment below, we are evaluating the stormwater control needs for the Chateau Valley Tower project. Our preliminary review indicates a new detention vault will be required. The existing handicap surface parking spaces located immediately south of the new building appears to be the only suitable location for a new facility. Since the sole purpose of excavating and replacing pavement in the existing parking lot is for installation of a new detention vault utility, we believe the construction qualifies for an exclusion under the 2017 Manual definition for Replaced impervious surface … excluding impervious surface removed for the sole purpose of installing utilities… , see page 1-7 of Manual. As we proceed into design, please confirm the detention facility construction zone will not be included in the replaced impervious surface areas. Thanks Cliff Williams, PE Development Management Engineers, LLC 206 714-7161 WWHM2012 PROJECT REPORT Chateau-Vault30 8/28/2019 4:34:44 PM Page 2 General Model Information Project Name: Chateau-Vault30 Site Name: Chateau Site Address: Davis Street City: Renton Report Date: 8/28/2019 Gage: Seatac Data Start: 1948/10/01 Data End: 2009/09/30 Timestep: 15 Minute Precip Scale: 1.000 Version Date: 2018/10/10 Version: 4.2.16 POC Thresholds Low Flow Threshold for POC1: 50 Percent of the 2 Year High Flow Threshold for POC1: 50 Year Chateau-Vault30 8/28/2019 4:34:44 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Flat 0.4512 Pervious Total 0.4512 Impervious Land Use acre Impervious Total 0 Basin Total 0.4512 Element Flows To: Surface Interflow Groundwater Chateau-Vault30 8/28/2019 4:34:44 PM Page 4 Mitigated Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Pasture, Mod 0.0982 Pervious Total 0.0982 Impervious Land Use acre ROOF TOPS FLAT 0.281 DRIVEWAYS FLAT 0.045 DRIVEWAYS MOD 0.012 DRIVEWAYS STEEP 0.0126 SIDEWALKS FLAT 0.0024 Impervious Total 0.353 Basin Total 0.4512 Element Flows To: Surface Interflow Groundwater Vault 1 Vault 1 Chateau-Vault30 8/28/2019 4:34:44 PM Page 5 Routing Elements Predeveloped Routing Chateau-Vault30 8/28/2019 4:34:44 PM Page 6 Mitigated Routing Vault 1 Width: 30 ft. Length: 39 ft. Depth: 7 ft. Discharge Structure Riser Height: 6 ft. Riser Diameter: 18 in. Orifice 1 Diameter: 0.37 in. Elevation:0 ft. Orifice 2 Diameter: 0.49 in. Elevation:3.302 ft. Orifice 3 Diameter: 0.34 in. Elevation:4.354 ft. Element Flows To: Outlet 1 Outlet 2 Vault Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.026 0.000 0.000 0.000 0.0778 0.026 0.002 0.001 0.000 0.1556 0.026 0.004 0.001 0.000 0.2333 0.026 0.006 0.001 0.000 0.3111 0.026 0.008 0.002 0.000 0.3889 0.026 0.010 0.002 0.000 0.4667 0.026 0.012 0.002 0.000 0.5444 0.026 0.014 0.002 0.000 0.6222 0.026 0.016 0.002 0.000 0.7000 0.026 0.018 0.003 0.000 0.7778 0.026 0.020 0.003 0.000 0.8556 0.026 0.023 0.003 0.000 0.9333 0.026 0.025 0.003 0.000 1.0111 0.026 0.027 0.003 0.000 1.0889 0.026 0.029 0.003 0.000 1.1667 0.026 0.031 0.004 0.000 1.2444 0.026 0.033 0.004 0.000 1.3222 0.026 0.035 0.004 0.000 1.4000 0.026 0.037 0.004 0.000 1.4778 0.026 0.039 0.004 0.000 1.5556 0.026 0.041 0.004 0.000 1.6333 0.026 0.043 0.004 0.000 1.7111 0.026 0.046 0.004 0.000 1.7889 0.026 0.048 0.005 0.000 1.8667 0.026 0.050 0.005 0.000 1.9444 0.026 0.052 0.005 0.000 2.0222 0.026 0.054 0.005 0.000 2.1000 0.026 0.056 0.005 0.000 2.1778 0.026 0.058 0.005 0.000 2.2556 0.026 0.060 0.005 0.000 2.3333 0.026 0.062 0.005 0.000 2.4111 0.026 0.064 0.005 0.000 2.4889 0.026 0.066 0.005 0.000 2.5667 0.026 0.068 0.006 0.000 2.6444 0.026 0.071 0.006 0.000 2.7222 0.026 0.073 0.006 0.000 2.8000 0.026 0.075 0.006 0.000 2.8778 0.026 0.077 0.006 0.000 Chateau-Vault30 8/28/2019 4:34:44 PM Page 7 2.9556 0.026 0.079 0.006 0.000 3.0333 0.026 0.081 0.006 0.000 3.1111 0.026 0.083 0.006 0.000 3.1889 0.026 0.085 0.006 0.000 3.2667 0.026 0.087 0.006 0.000 3.3444 0.026 0.089 0.008 0.000 3.4222 0.026 0.091 0.009 0.000 3.5000 0.026 0.094 0.009 0.000 3.5778 0.026 0.096 0.010 0.000 3.6556 0.026 0.098 0.011 0.000 3.7333 0.026 0.100 0.011 0.000 3.8111 0.026 0.102 0.011 0.000 3.8889 0.026 0.104 0.012 0.000 3.9667 0.026 0.106 0.012 0.000 4.0444 0.026 0.108 0.013 0.000 4.1222 0.026 0.110 0.013 0.000 4.2000 0.026 0.112 0.013 0.000 4.2778 0.026 0.114 0.014 0.000 4.3556 0.026 0.117 0.014 0.000 4.4333 0.026 0.119 0.015 0.000 4.5111 0.026 0.121 0.016 0.000 4.5889 0.026 0.123 0.016 0.000 4.6667 0.026 0.125 0.017 0.000 4.7444 0.026 0.127 0.017 0.000 4.8222 0.026 0.129 0.018 0.000 4.9000 0.026 0.131 0.018 0.000 4.9778 0.026 0.133 0.019 0.000 5.0556 0.026 0.135 0.019 0.000 5.1333 0.026 0.137 0.020 0.000 5.2111 0.026 0.140 0.020 0.000 5.2889 0.026 0.142 0.020 0.000 5.3667 0.026 0.144 0.021 0.000 5.4444 0.026 0.146 0.021 0.000 5.5222 0.026 0.148 0.021 0.000 5.6000 0.026 0.150 0.022 0.000 5.6778 0.026 0.152 0.022 0.000 5.7556 0.026 0.154 0.022 0.000 5.8333 0.026 0.156 0.023 0.000 5.9111 0.026 0.158 0.023 0.000 5.9889 0.026 0.160 0.023 0.000 6.0667 0.026 0.162 0.297 0.000 6.1444 0.026 0.165 0.893 0.000 6.2222 0.026 0.167 1.661 0.000 6.3000 0.026 0.169 2.526 0.000 6.3778 0.026 0.171 3.411 0.000 6.4556 0.026 0.173 4.241 0.000 6.5333 0.026 0.175 4.950 0.000 6.6111 0.026 0.177 5.494 0.000 6.6889 0.026 0.179 5.875 0.000 6.7667 0.026 0.181 6.231 0.000 6.8444 0.026 0.183 6.539 0.000 6.9222 0.026 0.185 6.832 0.000 7.0000 0.026 0.188 7.114 0.000 7.0778 0.026 0.190 7.384 0.000 7.1556 0.000 0.000 7.645 0.000 Chateau-Vault30 8/28/2019 4:34:44 PM Page 8 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 0.4512 Total Impervious Area: 0 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0.0982 Total Impervious Area: 0.353 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.013266 5 year 0.020834 10 year 0.025123 25 year 0.029668 50 year 0.032479 100 year 0.034871 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.008865 5 year 0.013912 10 year 0.01796 25 year 0.023947 50 year 0.029086 100 year Annual Peaks 0.034847 Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.013 0.006 1950 0.016 0.010 1951 0.029 0.021 1952 0.009 0.005 1953 0.007 0.007 1954 0.011 0.006 1955 0.018 0.006 1956 0.015 0.013 1957 0.012 0.006 1958 0.013 0.008 Chateau-Vault30 8/28/2019 4:36:19 PM Page 9 1959 0.011 0.006 1960 0.020 0.018 1961 0.011 0.011 1962 0.007 0.005 1963 0.010 0.007 1964 0.013 0.010 1965 0.009 0.012 1966 0.009 0.006 1967 0.018 0.010 1968 0.011 0.006 1969 0.011 0.006 1970 0.009 0.007 1971 0.010 0.007 1972 0.022 0.018 1973 0.010 0.012 1974 0.011 0.007 1975 0.015 0.006 1976 0.011 0.006 1977 0.001 0.006 1978 0.009 0.010 1979 0.006 0.005 1980 0.021 0.018 1981 0.008 0.006 1982 0.016 0.015 1983 0.014 0.007 1984 0.009 0.005 1985 0.005 0.006 1986 0.023 0.012 1987 0.020 0.017 1988 0.008 0.006 1989 0.005 0.006 1990 0.043 0.018 1991 0.026 0.017 1992 0.010 0.010 1993 0.010 0.005 1994 0.003 0.005 1995 0.015 0.012 1996 0.031 0.021 1997 0.026 0.020 1998 0.006 0.005 1999 0.024 0.018 2000 0.010 0.009 2001 0.002 0.005 2002 0.011 0.012 2003 0.014 0.006 2004 0.019 0.021 2005 0.013 0.006 2006 0.016 0.013 2007 0.032 0.037 2008 0.041 0.020 2009 0.020 0.013 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0425 0.0373 2 0.0407 0.0214 3 0.0316 0.0213 Chateau-Vault30 8/28/2019 4:36:19 PM Page 10 4 0.0311 0.0206 5 0.0292 0.0204 6 0.0260 0.0202 7 0.0256 0.0185 8 0.0244 0.0182 9 0.0230 0.0180 10 0.0218 0.0178 11 0.0206 0.0175 12 0.0203 0.0172 13 0.0200 0.0172 14 0.0198 0.0148 15 0.0186 0.0134 16 0.0182 0.0133 17 0.0180 0.0128 18 0.0162 0.0125 19 0.0158 0.0124 20 0.0157 0.0123 21 0.0147 0.0117 22 0.0145 0.0116 23 0.0145 0.0112 24 0.0143 0.0100 25 0.0142 0.0099 26 0.0133 0.0098 27 0.0132 0.0096 28 0.0130 0.0095 29 0.0125 0.0092 30 0.0117 0.0082 31 0.0114 0.0067 32 0.0113 0.0067 33 0.0113 0.0067 34 0.0112 0.0066 35 0.0111 0.0066 36 0.0110 0.0066 37 0.0107 0.0065 38 0.0105 0.0065 39 0.0103 0.0064 40 0.0103 0.0064 41 0.0099 0.0064 42 0.0099 0.0063 43 0.0097 0.0063 44 0.0095 0.0063 45 0.0092 0.0062 46 0.0092 0.0061 47 0.0091 0.0061 48 0.0090 0.0059 49 0.0088 0.0059 50 0.0086 0.0059 51 0.0082 0.0057 52 0.0080 0.0056 53 0.0074 0.0056 54 0.0069 0.0055 55 0.0059 0.0054 56 0.0056 0.0054 57 0.0052 0.0053 58 0.0052 0.0052 59 0.0035 0.0050 60 0.0018 0.0048 61 0.0013 0.0047 Chateau-Vault30 8/28/2019 4:36:19 PM Page 11 Chateau-Vault30 8/28/2019 4:36:19 PM Page 12 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.0066 17545 12260 69 Pass 0.0069 16159 10322 63 Pass 0.0072 14964 10044 67 Pass 0.0074 13849 9758 70 Pass 0.0077 12810 9486 74 Pass 0.0079 11807 9206 77 Pass 0.0082 10898 8938 82 Pass 0.0085 10119 8622 85 Pass 0.0087 9383 8297 88 Pass 0.0090 8729 7976 91 Pass 0.0092 8143 7649 93 Pass 0.0095 7593 7255 95 Pass 0.0098 7060 6902 97 Pass 0.0100 6594 6545 99 Pass 0.0103 6158 6190 100 Pass 0.0105 5788 5809 100 Pass 0.0108 5431 5437 100 Pass 0.0111 5097 5043 98 Pass 0.0113 4808 4629 96 Pass 0.0116 4528 4327 95 Pass 0.0119 4256 4015 94 Pass 0.0121 4019 3739 93 Pass 0.0124 3788 3463 91 Pass 0.0126 3553 3262 91 Pass 0.0129 3341 3035 90 Pass 0.0132 3140 2813 89 Pass 0.0134 2950 2558 86 Pass 0.0137 2785 2400 86 Pass 0.0139 2599 2160 83 Pass 0.0142 2449 1992 81 Pass 0.0145 2308 1841 79 Pass 0.0147 2162 1747 80 Pass 0.0150 2028 1693 83 Pass 0.0152 1903 1643 86 Pass 0.0155 1790 1584 88 Pass 0.0158 1687 1498 88 Pass 0.0160 1586 1405 88 Pass 0.0163 1483 1329 89 Pass 0.0166 1381 1241 89 Pass 0.0168 1293 1154 89 Pass 0.0171 1221 1062 86 Pass 0.0173 1155 963 83 Pass 0.0176 1098 887 80 Pass 0.0179 1049 806 76 Pass 0.0181 997 701 70 Pass 0.0184 930 633 68 Pass 0.0186 883 555 62 Pass 0.0189 837 499 59 Pass 0.0192 789 447 56 Pass 0.0194 743 396 53 Pass 0.0197 713 352 49 Pass 0.0199 670 307 45 Pass 0.0202 633 261 41 Pass Chateau-Vault30 8/28/2019 4:36:19 PM Page 13 0.0205 596 226 37 Pass 0.0207 565 190 33 Pass 0.0210 539 165 30 Pass 0.0213 497 135 27 Pass 0.0215 473 113 23 Pass 0.0218 435 109 25 Pass 0.0220 401 103 25 Pass 0.0223 369 85 23 Pass 0.0226 348 66 18 Pass 0.0228 323 56 17 Pass 0.0231 296 47 15 Pass 0.0233 272 38 13 Pass 0.0236 256 29 11 Pass 0.0239 235 11 4 Pass 0.0241 217 10 4 Pass 0.0244 197 10 5 Pass 0.0246 180 10 5 Pass 0.0249 158 10 6 Pass 0.0252 145 10 6 Pass 0.0254 129 10 7 Pass 0.0257 119 9 7 Pass 0.0260 109 9 8 Pass 0.0262 97 9 9 Pass 0.0265 91 9 9 Pass 0.0267 82 8 9 Pass 0.0270 76 5 6 Pass 0.0273 69 5 7 Pass 0.0275 61 5 8 Pass 0.0278 54 5 9 Pass 0.0280 48 5 10 Pass 0.0283 41 5 12 Pass 0.0286 38 5 13 Pass 0.0288 33 5 15 Pass 0.0291 27 4 14 Pass 0.0293 22 3 13 Pass 0.0296 21 3 14 Pass 0.0299 20 3 15 Pass 0.0301 19 3 15 Pass 0.0304 17 3 17 Pass 0.0307 13 3 23 Pass 0.0309 12 3 25 Pass 0.0312 9 3 33 Pass 0.0314 4 3 75 Pass 0.0317 3 3 100 Pass 0.0320 3 3 100 Pass 0.0322 3 2 66 Pass 0.0325 3 2 66 Pass Chateau-Vault30 8/28/2019 4:36:19 PM Page 14 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Chateau-Vault30 8/28/2019 4:36:19 PM Page 15 LID Report Chateau-Vault30 8/28/2019 4:37:40 PM Page 16 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. Chateau-Vault30 8/28/2019 4:37:40 PM Page 17 Appendix Predeveloped Schematic Chateau-Vault30 8/28/2019 4:37:42 PM Page 18 Mitigated Schematic Chateau-Vault30 8/28/2019 4:37:45 PM Page 19 Predeveloped UCI File Chateau-Vault30 8/28/2019 4:37:45 PM Page 20 Mitigated UCI File Chateau-Vault30 8/28/2019 4:37:45 PM Page 21 Predeveloped HSPF Message File Chateau-Vault30 8/28/2019 4:37:45 PM Page 22 Mitigated HSPF Message File Chateau-Vault30 8/28/2019 4:37:45 PM Page 23 Disclaimer Legal Notice This program and accompanying documentation are provided 'as -is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. C lear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005 -2019; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com