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HomeMy WebLinkAbout32-TIR Full_16Mar23 (1)drainage reportTCE 548 Front Street South, Issaquah, WA 98027 Renton Restaurant Addition 17630 108th Avenue SE Renton, WA Technical Information Report March 2016 Prepared by Shailesh Tatu, PE, PM, M. Tech. Tatu Consulting Engineers 548 Front Street South Suite 100 Issaquah, WA 98027 TCE Renton Restaurant Addition Page 2 of 10 Table of Contents Section 1 – Project Overview Section 2 – Conditions and Requirements Summary Section 3 – Off-site Analysis Section 4 – Flow Control and Water Quality Facility Analysis and Design Section 5 – Conveyance System Analysis and Design Section 6 – Special Reports and Studies Section 7 – Other Permits Section 8 – ESC Analysis and Design Section 9 – Bond Quantities Section 10 – Operations and Maintenance Manual Figure 1 TIR Worksheet Figure 2 Vicinity Map Figure 3 NRCS Soils Map Figure 4 Existing Site Conditions Figure 5 Developed Site Conditions Figure 6 Contributing Basin Map & Existing Conditions TCE Renton Restaurant Addition Page 3 of 10 FIGURE 1 - TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PART 1 PROJECT OWNER AND PROJECT ENGINEER PART 2 PROJECT LOCATION AND DESCRIPTION Project Owner: Wen Tian Address 2605 82nd Avenue NE, Medina, WA Contact Telephone 425-615-6108 Project Engineer: Shailesh Tatu, PE Project Name: Renton Restaurant Addition Location: 17630 108th Ave SE, Renton, WA Township: 23N Range: 05E Section: NE ¼ 32 PART 3 TYPE OF PERMIT APPLICATION PART 4 OTHER REVIEWS AND PERMITS Subdivision Short Plat Grading Commercial Other DFW HPA COE 404 DOE Dam Safety FEMA Floodplain COE Wetlands Shoreline Management Rockery Structural Vaults Other PART 5 SITE COMMUNITY AND DRAINAGE BASIN Community Soos Creek Drainage Basin Black River PART 6 SITE CHARACTERISTICS River ------------------------------------------------------------- Stream Critical Stream Reach Depressions/Swales Lake ------------------------------------------------------------ Steep Slopes --------------------------------------------------- Floodplain ---------------------------------------------------------------- Wetlands Category II buffer Seeps/Springs High Groundwater Table Groundwater Recharge Other --------------------------------------------------------------------- PART 7 SOILS Soil Type Slopes Erosion Potential Erosive Velocities Alderwood AgB 0 to 6 % Slight 3 FPS Additional Sheets Attached TCE Renton Restaurant Addition Page 4 of 10 FIGURE 1 - TECHNICAL INFORMATION REPORT (TIR) WORKSHEET PART 8 DEVELOPMENT LIMITATIONS REFERENCE LIMITATION/SITE CONSTRAINT Additional Sheets Attached PART 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Sedimentation Facilities Stabilized Construction Entrance Perimeter Runoff Control Clearing & Grading Restrictions Cover Practices Construction Sequence Other Tree Protection MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION Stabilize Exposed Surface Remove and Restore Temporary ESC Facilities Clean and Remove All Silt & Debris Ensure Operation of Permanent Facilities Flag Limits of SAO and Open Space Preservation Areas Other PART 10 SURFACE WATER SYSTEM Grass Lined Channel Pipe System Open Channel Dry Pond Wet Pond Tank Vault Energy Dissipater Wetland Stream Infiltration Depression Flow Dispersal Waiver Regional Detention Brief Description of System Operation: Surface flow will continue to be collected in existing catch basins and pipe then Conveyed to an existing detention tank. Facility Related Site Limitations Reference Facility Limitation PART 11 STRUCTURAL ANALYSIS PART 12 EASEMENTS/TRACTS Cast in Place Vault Retaining Wall Rockery > 4' High Structural on Steep Slope Retaining Wall Drainage Easement Access Easement Native Growth Protection Easement Tract Other Part 13 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attachments. To the best of my knowledge the information provided here is accurate. Signed/Date TCE Renton Restaurant Addition Page 5 of 10 Section 1 – Project Overview The project consists of addition to an existing restaurant located at 17930 108th Avenue SE. The existing KC parcel (#252604-9019) is approximately 37,874 square feet (0.85 acres) in size and contains an existing restaurant building with about 5,000 square feet roof, along with walkways, asphalt pavement and parking. Please refer to Figure 4, Existing Conditions. The site is considered flat with average gentle slopes (about 3%). The parcel is zoned C, and is located in the NE Quarter of Section 31, Township 23 N, Range 5 E, W.M. King County, Washington. The project site is shown in the vicinity map. The addition around the existing restaurant will make the roof area about 8,348 square feet. The outer edges of the asphalt pavement will be expanded with the use of permeable asphalt. Most of the asphalt pavement will remain as is. Walkways around the restaurants will be constructed over the existing base course of the existing pavements, without disturbing the subgrade, so as not to be counted as new impervious surface. An existing drainage system consisting of catch basins and drains will continue to service the development without alteration. An existing detention tank also will continue to service the development without alteration. The additional pavement being permeable asphalt does not impact the facility in a significant way. Existing trees along the east and west will be preserved and a couple of interior ornamental trees will be relocated on site. The Existing soils on the site are mapped by the NRCS as being type AgB – Alderwood Gravelly Sandy Loam. Please refer to Figure 3, NRCS Soils Map below. The Hydrologic Group of AgB is B TCE Renton Restaurant Addition Page 6 of 10 Section 2 – Conditions and Requirements Summary The following summary describes how this project will meet the eight “Core Requirements” and the “Special Requirements” that apply: Core Requirements 1. Discharge at the natural location: This site currently sheet flows to the west and collects in existing catch basins. From these catch basins the surface water is conveyed by 8” drains to an existing detention tank located along the west property line. The discharge from the detention tank is to the City drainage system located within 108th Avenue SE right of way. The proposed drainage system for this project will continue to collect the surface water runoff at the same catch basins, draining to the same detention pipe, and then continue to discharge to the same existing City drainage system located within 108th Avenue SE right of way. No change in the existing discharge location is proposed. 2. Off-site Analysis: A Level 1 off-site analysis was completed for this project and is included in Section 3 of this Technical Information Report. No significant downstream drainage problems were found. 3. Flow control: The proposed method of flow control is to continue to utilize the same existing detention tank. The extension of the paving will be provided by permeable asphalt, thereby infiltrating the runoff from the expanded parking area. Please refer to Figure 6, Contributing Basin Map and Section 4 of this report. 4. Conveyance system: Flows will be conveyed using the existing catch basins and tight line culverts. 5. Erosion and sedimentation control: A Temporary Erosion and Sedimentation Control plan, notes and details are included in this engineering submittal. 6. Maintenance and Operations: The existing storm drainage collection system on the property will continue to be privately owned and maintained. With the right of way dedication, the existing detention system comes to be located in the right of way, and therefore, the detention facility will be owned and operated by the City. Please refer to Section 10 of this report. 7. Financial guarantees and liability: The owner/contractor will be required to post construction performance and one year maintenance bonds for the redevelopment work associated with this project. A bond quantities spreadsheet for the proposed development will be prepared as required upon initial City review of the engineering plans. TCE Renton Restaurant Addition Page 7 of 10 8. Water Quality: The new impervious surface subject to vehicular traffic does not meet the threshold of greater than 5,000 square feet for this project. As a result, the project will not be providing water quality treatment. Special Requirements 1. Other adopted area-specific requirements: Enhanced Flow Control 2. Floodplain/Floodway delineation: Not applicable. 3. Flood protection facilities: Not applicable. 4. Source controls: No storage of hazardous substances exposed to elements. 5. Oil Control: Not a high use site. TCE Renton Restaurant Addition Page 8 of 10 Section 3 – Off-site Analysis This Level 1 Downstream Analysis is submitted as required by Core Requirement #2, Section 1.2.2, of the 2009 KCSWDM. Core Requirement #2 requires a qualitative analysis of upstream and downstream drainage conditions with an initial project submittal. Task 1: Study Area Definition and Maps: See Section-1 Project Overview of this report for a detailed Study Area Definition. Task 2: Resource Review: A sensitive areas review shows no critical areas on or near the project site. There were numerous official drainage complaint records on file with King County that are surrounding this property. It appears most of these are very old complaints and have been closed for quite a while. They relate to annexation of the area and new municipal code requirements regarding water quality issues noticed during jurisdiction staff. The complaint in the subject property was closed on 9/29/04. Task 3: Field Inspection: A field observation of the site and downstream analysis were performed on March 18, 2016. The weather was overcast during visit. Field observations did not reveal any apparent drainage issues downstream, Task 4: Drainage System Description and Problem Descriptions: Upstream: There are no upstream drainage conditions, because the drainage system within 109th Avenue SE has its drainage system that cuts the drainage away from the site. The slope on the properties to the north and south is parallel to the project site and they do not transfer any runoff on to this project site. Downstream: The downstream drainage system is the City drainage system in 108th Avenue SE flowing south: The discharge from the site goes down this system to the south and then turns west down slope to the quarter mile location. The drainage system in 108th Avenue SE and down is substantial in size and at a reasonable slope. The drainage path, as described, appears to have adequate capacity and no current problems were observed during our field investigation. Task 5 – Mitigation of Existing or Potential Problems: Existing capacity in the downstream system has been evaluated to be adequate to provide conveyance for the discharge from this project. TCE Renton Restaurant Addition Page 9 of 10 Section 4 – Proposed Site Conditions and Design Parameters Flow Control Analysis and Design In the existing conditions the flow control for this project is provided by an existing detention tank located along the west property line. The same detention tank will continue to be used for proposed conditions because additional asphalt is permeable asphalt which does not generate new runoff. The detention system is a 36” diameter 60’ long with a type II catch basin at each end of it. The control structure is 54” in diameter and the other being a 48” diameter structure. Please see the drainage basin maps included in this report for the proposed and existing drainage basins. Water Quality Analysis and Design No pollution generating impervious area is being added to the existing condition. All new pavement proposed is permeable asphalt that infiltrates inti the subgrade and does not generate any additional runoff. TCE Renton Restaurant Addition Page 10 of 10 Section 5 – Conveyance System Analysis and Design The existing conveyance system on site has been serving the existing development adequately and appears to be reasonable in size and slope. The proposed development would not generate any additional runoff due to the employment of the permeable pavement for the pavement to be added. Therefore in our opinion the existing conveyance system is adequate to service the proposed development too. Section 6 – Special Reports and Studies We are not aware of any Special Reports or Studies associated with the property proposed to be redeveloped or in the near vicinity. Section 7 – Other Permits City of Renton Building Permit Soos Creek Water & Sewer District water, sewer, fire, and irrigation services approval. Section 8 – ESC Analysis and Design Standard erosion and sedimentation control BMPs are proposed. Drawing sheet C-1 is dedicated to show clearing limits, construction entrance, dust control, inlet protection, matting & mulching, silt fence, and tree protection. Prior to beginning any work these BMPs will be installed and operational. Upon completion of earthwork and stabilization of worked areas, these NMPs will be removed. Section 9 – Financial Guarantees The project proposes to add new dining area around the shell of the existing building. Permeable asphalt is proposed to facilitate expansion of paved areas on site. The work in the right of way consists of replacing the existing driveway entrance with a driveway entrance to current standards. Our understanding is that at this time the right of way will be dedicated. The work in the right of way will be limited to that associated with the installation of the new driveway entrance, such as sidewalk reconnection and curb tapering to the driveway entrance. The bond quantities will be submitted upon clarification of the scope of work in the right of way. Section 10 – Operations and Maintenance Manual We are not sure if our proposal regarding leaving the existing detention tank unaltered and reusing it would be acceptable to the City. Upon resolution of this question the operation and maintenance manual will be submitted. King County Vicinity iMap Date: 1/27/2016 Notes: ±The information included on this map has been compiled by King County staff from a variety of sources and is subject to change without notice. King County makes no representations or warranties, express or implied, as to accuracy, completeness, timeliness,or rights to the use of such information. This document is not intended for use as a survey product. King County shall not be liable for any general, special, indirect, incidental, or consequential damages including, but not limited to, lost revenues or lost profits resulting from the use or misuse of the information contained on this map. Any sale of this map or information on this map is prohibited except by written permission of King County. Site SR 167 S Carr Rd 108th Ave SE Hydrologic Soil Group—King County Area, Washington(Tenton Restaurant Addition)Natural ResourcesConservation ServiceWeb Soil SurveyNational Cooperative Soil Survey3/22/2016Page 1 of 45254780525479052548005254810525482052548305254840525478052547905254800525481052548205254830525484056056056057056058056059056060056061056062056063056064056065056056056057056058056059056060056061056062056063056064056065047° 26' 39'' N122° 11' 48'' W47° 26' 39'' N122° 11' 43'' W47° 26' 37'' N122° 11' 48'' W47° 26' 37'' N122° 11' 43'' WNMap projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS840 20 40 80 120Feet0 5 10 20 30MetersMap Scale: 1:458 if printed on A landscape (11" x 8.5") sheet. MAP LEGENDMAP INFORMATIONArea of Interest (AOI)Area of Interest (AOI)SoilsSoil Rating PolygonsAA/DBB/DCC/DDNot rated or not availableSoil Rating LinesAA/DBB/DCC/DDNot rated or not availableSoil Rating PointsAA/DBB/DCC/DDNot rated or not availableWater FeaturesStreams and CanalsTransportationRailsInterstate HighwaysUS RoutesMajor RoadsLocal RoadsBackgroundAerial PhotographyThe soil surveys that comprise your AOI were mapped at 1:24,000.Warning: Soil Map may not be valid at this scale.Enlargement of maps beyond the scale of mapping can causemisunderstanding of the detail of mapping and accuracy of soil lineplacement. The maps do not show the small areas of contrastingsoils that could have been shown at a more detailed scale.Please rely on the bar scale on each map sheet for mapmeasurements.Source of Map: Natural Resources Conservation ServiceWeb Soil Survey URL: http://websoilsurvey.nrcs.usda.govCoordinate System: Web Mercator (EPSG:3857)Maps from the Web Soil Survey are based on the Web Mercatorprojection, which preserves direction and shape but distortsdistance and area. A projection that preserves area, such as theAlbers equal-area conic projection, should be used if more accuratecalculations of distance or area are required.This product is generated from the USDA-NRCS certified data as ofthe version date(s) listed below.Soil Survey Area: King County Area, WashingtonSurvey Area Data: Version 11, Sep 14, 2015Soil map units are labeled (as space allows) for map scales 1:50,000or larger.Date(s) aerial images were photographed: Aug 31, 2013—Oct 6,2013The orthophoto or other base map on which the soil lines werecompiled and digitized probably differs from the backgroundimagery displayed on these maps. As a result, some minor shiftingof map unit boundaries may be evident.Hydrologic Soil Group—King County Area, Washington(Tenton Restaurant Addition)Natural ResourcesConservation ServiceWeb Soil SurveyNational Cooperative Soil Survey3/22/2016Page 2 of 4 Hydrologic Soil GroupHydrologic Soil Group— Summary by Map Unit — King County Area, Washington (WA633)Map unit symbolMap unit nameRatingAcres in AOIPercent of AOIAgBAlderwood gravellysandy loam, 0 to 8percent slopesB0.785.3%AgCAlderwood gravellysandy loam, 8 to 15percent slopesB0.114.7%Totals for Area of Interest0.8100.0%DescriptionHydrologic soil groups are based on estimates of runoff potential. Soils areassigned to one of four groups according to the rate of water infiltration when thesoils are not protected by vegetation, are thoroughly wet, and receive precipitationfrom long-duration storms.The soils in the United States are assigned to four groups (A, B, C, and D) andthree dual classes (A/D, B/D, and C/D). The groups are defined as follows:Group A. Soils having a high infiltration rate (low runoff potential) when thoroughlywet. These consist mainly of deep, well drained to excessively drained sands orgravelly sands. These soils have a high rate of water transmission.Group B. Soils having a moderate infiltration rate when thoroughly wet. Theseconsist chiefly of moderately deep or deep, moderately well drained or well drainedsoils that have moderately fine texture to moderately coarse texture. These soilshave a moderate rate of water transmission.Group C. Soils having a slow infiltration rate when thoroughly wet. These consistchiefly of soils having a layer that impedes the downward movement of water orsoils of moderately fine texture or fine texture. These soils have a slow rate of watertransmission.Group D. Soils having a very slow infiltration rate (high runoff potential) whenthoroughly wet. These consist chiefly of clays that have a high shrink-swellpotential, soils that have a high water table, soils that have a claypan or clay layerat or near the surface, and soils that are shallow over nearly impervious material.These soils have a very slow rate of water transmission.If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter isfor drained areas and the second is for undrained areas. Only the soils that in theirnatural condition are in group D are assigned to dual classes.Hydrologic Soil Group—King County Area, WashingtonTenton Restaurant AdditionNatural ResourcesConservation ServiceWeb Soil SurveyNational Cooperative Soil Survey3/22/2016Page 3 of 4 Rating OptionsAggregation Method: Dominant ConditionComponent Percent Cutoff: None SpecifiedTie-break Rule: HigherHydrologic Soil Group—King County Area, WashingtonTenton Restaurant AdditionNatural ResourcesConservation ServiceWeb Soil SurveyNational Cooperative Soil Survey3/22/2016Page 4 of 4 EXISTING CONDITIONS MAP PROPOSED CONDITIONS MAP EXISTING DRAINAGE BASINS PROPOSED DRAINAGE BASINS