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HomeMy WebLinkAboutMiscI I I I I I I I I I I I I I I I I I I I [P)~~[bD~D[NJ~IRnr If'~~[K]INlD~~[b 0 [NJ[F(Q)~M~ LrD(Q)1Nl [Ri~jp)(Q)~Lr CityOfR Planning D.e~ton IVISion JUL 1 0 lI}(J9 1R1~©~U~~@ Proposed Ren~o81 Gateway Center 750 West Perimeter Road Renton Airport, Renton, Washington 98055 Prepared for: Pro Flight Aviation Inc. 243 West Perimeter Road Renton, Washington 98055 June 26, 2009 Our Job No. 12564 ~i i CIVIL ENGINEERING, LAND PLANNING, SURVEYING 18215 72ND AvENUE SOUTH KENT, WA 98032 (425) 251-6222 (425) 251-8782 FAX BRANCH OFFICES <> OLYMPIA,WA <> TACOMA,WA <> CONCORD,CA <> TEMECULA,CA www.barghausen.com I I I I I I I I I I I I I I , I II I I I 1.0 2,0 3,0 TABLE OF CONTENTS PROJECT OVERVIEW Figure I -Technical Information Report (TIR) Worksheet Figure 2 -Site Location PRELIMINARY CONDITIONS SUMMARY 2, I Analysis of the Five Core Requirements 2.2 Analysis of the Special Requirements OFF-SITE ANALYSIS 12564,OOldoe I I I I I I I I I 11.0 PROJECT OVERVKEW I I I I I I I II II I I I I I I I I I I I I I I I I I I I I 1.0 PROJECT OVERVIEW This site is located within a portion of the Southwest quarter of Section 7, Township 23 North, Range 5 East, Willametle Meridian, City of Renton, King County, Washington, and comprises approximately 1.47 acres. More particularly, the site is located at 750 West Perimeter Road, Renton Airport, Renton, Washington. The attached Vicinity Map gives the exact location of the project site. The proposal for this development is to construct eight aircraft hangars, six of which will be used for aircraft storage, and two of which will be used for maintenance of aircraft, along with an additional building for the purpose of providing pilot concierge service. In addition, existing asphalt on the site will be modified and replaced with new asphalt to allow for the parking of approximately 24 automobiles along the west side of the proposed hangar structures. The existing site is almost entirely imperviolls surface consisting of buildings and pavement with the remaining area of gravel or dirt. Under proposed conditions, much of this gravel/dirt area will be converted into landscaping, which should actually decrease the amount of runoff coming off the project site; however, the total impervious surface on the project site will increase by a slight amount of approximately 900 square feet. Detention and water quality are not proposed nor required for this project site. There is an existing 7-foot by 5-foot reinforced concrete box culvert located underneath Perimeter Road immediately west of the project site that this site will drain to. There are existing catch basins on the project site that discharge into this reinforced concrete box culvert that will be utilized with this new development. Since this project site is located on a portion of an airport, the project site is relatively flat in nature. It is anticipated there will be minimal grading to OCCllr, with site grades staying much the way they are. Please refer to the existing and proposed Site Land Coverage table on the following pages of this repOlt for a complete description of the site land covers. 12564.003.doc I I I I I I I I I I I I I I I I I I I EXISTING AND PROPOSED SITE LAND COVERS Existing Condition: Building 1,165 SF Pavement 45,162 SF Gravel/Dirt 17,682 SF TOTAL ~ 64,009 SF Proposed Condition: Building ~ 30,150SF Pavement ~ 16,897 SF Concrete 198 SF Landscaping ~ 13,759 SF Gravel/Dirt 3,005 SF TOTAL ~ 64,009 SF 12564 .003.doc I I I I I I I I I I I I I I I I I I I JF][GURE ] TECHNICAL ][NJFORMAT][ON REPORT ('fIR) WORKSHEET I I I I I I I I I I I I I I I I 'I I Page 1012 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Project Owner Pro FlightA'lialion.-Llnrnc'--___ _ Address 243 West Perimeter Road Renton WA 98055 $ ; Phone (425)228-9510 Project Engineer Costa Pbilippides Company Barghausen Consulting Engineers, Iwoc"----__ Address Phone 182 J 5 -nnd Avenue South, Kent, WA D Subdivision o Short Subdivision [XJ Grading [XJ Commercial C] Other ,~= ·(_lk:Jillei~l.:J~ Community Renton Drainage Basin Lake Washington "'~.'.'.' . .. ~: D 0 D 0 D Project Name Renton Gateway Center Location Township .1lJ'!ru:th __ _ Range 5 East Section -'7'----__ _ Project Size J 47 Acres AC Upstream Drainage Basin Size ____ AC DOF/GHPA 0 Shoreline Management CaE 404 0 Rockery DOE Dam Safely 0 Structural Vaults FEMA Ftoodplain !XI Other NPDES COEWeliands D HPA D River ______________ _ D Floodplain ______________ _ D Stream _____________ _ o Critical Stream Reach o DepressionS/Swales D lake D Steep Stopes D LakesidelErosion Hazard D Wetlands _______________ _ D Seeps/Springs D High Groundwater Table D Groundwater ReCharge D Other SOIl!S'~ '.' , ,,"""""r~~~~~~-------~-:J ~"~_-...""~a~,~","""".~>i~~ ..... ~"'~~~""""',~,_~="'~~~ ... ,.....,,~~''''''- SoitType Urban Land stopas ------',---- D Additional Sheets Altatched 12564.004.pdf Erosion Potential E(Qsive Velocities 1/90 I I I I I I I I I I I I I I I I I Page 2 of 2 King County Building and Land Development Division TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Imffi]@ i'iJ3YlID<.jiO!l'illlIDfllh~IWti[.® .. 0 . REFERENCE LIMITATION/SITE CONSTRAINT 0 Ch. 4 -Downslream Analysis -------- 0 - 0 0 0 - 0 0 Additional Sheels Matched Imffi]@ ~l;I:('! 1I;j;!ltI:hhj;j ..... 0 0 MINIMUM ESC REOUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION FOLLOWING CONSTRUCTION !Xl Sedimentation Facilitios [Xl Stabilize Exposed Surface !Xl Stabilized Construction Enlrance IX1 Remove and Rostore Temporary ESC Facilities !Xl Perimeter Runoff Control OCI Cloan and Romove All Silt and Debris 0 Clearing and Grading Restrictions [Xl Ensure Operation 01 Permanent Facilities 0 Cover Practices 0 Flag limits of NGPES IX! Conslruction Sequence 0 Other 0 Other !a'i!ill'® ~15!b.§@iI€Xkilili'LJ 0 Grass lined Channel 0 Tank 0 Infiltration Method of Analysis !Xl Pipe System 0 Vaull 0 Depression 0 Open Channel 0 Energy Dlssapator 0 Flow Dispersal CompensationlMitigation 0 Dry Pond 0 Wetland 0 Waiver of Eliminated Site Storage 0 Wet Pond 0 Stream 0 Regional Detention Brief Description of System Operation Catch basin collection to pipe conveyance to discharge off site. Facility Related Site limitations Reference Facility Umltation o Additionat Sheets Attatched o Drainage Easement o Cast in Plaoe Vaull 0 Other o Access Easement o Retaining Wall o Native Growth Protection Easement o Rackery> 4'High o Tract o Structural on Stoop Slope o Other I or 0 civil onginoor undor my suporvision hovo visitod Iho sito. Actual ./'1 A " sito conditions os obsorvod ware incorporated into this workshoot and the £..L,.A~~~ ~.r Lt.J /_ .. ?4-Jl1C altatchments. To tho best of my knowlodgo the information providod ru c,..--LV'I hero.~s nccurato. -.-----------------------,"/---;1/'--"/7/71'7"'"-<-"""'"---"-'"-----__ _ 12564.004.pdf (/ f/ {/'-·---ltiO 1 I I I I I I I I I I I FKGURE 2 SK'fE LOCATKON I I I I I I I I II I I I I I I I I I I I I I I I I I I I I ~""'---"1--------" ~ REFERENCE: Thomas Guide (2006) Horizontal: N. r.S . VfHticaI: HlA 18215 72NDAVENUE SOUTH KENT, WA 98032 (425) 251-6222 (425) 251-6782 CIVIL ENGINEERING, lAND PlANNING , SURVEYING , EtMRONMENTAL. SERVICES P:\12OOOa\125tU\8xhlblt\12504 vrnap .cdr For: RENTON GATEWAY CENTER RENTON, WASHINGTON Title: VICINITY MAP Job Number 12564 I I I I I I I I I 2.0 PRJEJLlIMlINARY CON]]J)lI],lIONS SUMMARY I I I I I I I I II I I I 2.0 I I I I I I I I I I I I I I I PRELIMINARY CONDITIONS SUMMARY 2.1 2.2 Analysis of the Five Core Requirements Core Requirement No. I: Discharge at the Natural Location. Resl)onse: This site will discharge into the 7-foot by 5-foot reinforced concrete box culvert underneath Perimeter Road. which courses in a northerly direction on the west side of the project site just as it does under existing conditions. Therefore, this Core Requirement is met. Core Requirement No.2: Ojj:Site Analysis. Response: No off-site analysis is required for this project site as it is an already developed site and the City is well aware of the downstream drainage course from this project site. In addition, the site has almost direct discharge into Lake Washington at the northern end of the airport. Core Requirement No.3: RunofJContraJ. Response: Since only 900 square feet of impervious surface is being added with this project, runoff control in the form of detention is not a requirement for this project site. The entire existing site could be considered impervious surface. Core Requirement No.4: Conveyance System. Response: The conveyance system for this project site will be sized in accordance with the 1990 King County Surface Water Design Manual such that the Modified Rational Method will be utilized to size the conveyance elements for this project site with a 3.4-inch 25-year precipitation rate, a Manning's 'n' value of 0.014, and an initial time of concentration of 6.3 minutes. This is a very conservative sizing methodology and provides safe conveyance elements. Core Requirement No.5: Temporm), Erosion and Sedimentation Control. Response: A temporary erosion and sedimentation control plan will be prepared with this project such that clearing limits will be specified, cover measures will be utilized should there be stockpiling of dirt anywhere on the project site, perimeter protection will be installed in the form of silt fences along the downstream perimeter of the project site to prevent sediment-laden runoff from leaving the project site, traffic area stabilization will be provided in the fonn of a rock construction entrance with the adjacent streets being swept on a daily basis should be sediment be tracked off site, and dust control will be utilized should this project be constructed during the drier summer months. Analysis of the Special Requirements Special Requirement No. I: Critical Drainage Areas. Response: This site is not located within a critical drainage area; therefore, the requirements of Special Requirement No. I do not apply. 12S64.003.doc I I I I I I I I I I I I I I I I Special Requirement No.2: Compliance with an Existing Master Drainage Plan. Response: This project site does not lie within an area with a master drainage plan. Special Requirement No.3: Conditions Requiring a Master Drainage Plan. Response: This project site does not meet the threshold of this special requirement; therefore, a master drainage plan is not required. Special Requirement No.4: Adopted Basin or Community Plan. Response: This project site does not lie within an adopted basin or community plan to the best of our knowledge. Special Requirement No.5: Special Water Quali(v Controls. Response: The City has already indicated special water quality controls will not be required for this project site. Special Requirell/ent No.6: Coalescing Plate Oil/Water Separator. Response: This project does not meet the threshold of this Special Requirement and does not require any coalescing plate oillwater separators. Special Requirement No.7: Closed Depressions. Response: This project site does not discharge runoff to an existing closed depression. Special Requirement No.8: Use of Lakes, Wetlands, or Closed Depressions for Peak Rate Runoff Control. Response: This project is proposing the use of a lake for peak rate runoff control; however, the requirements of this Special Requirement do not apply to this site. Special Requiremellt No.9: Delineatioll of 100-Year Floodplain. Response: This project abuts a lake; however, it is an airport and the site is well above the elevation of the lake and the lake has a secure outfall. Therefore, there is no IOO-year floodplain on this project site. Special Requirement No. 10: Flood Protection Facilities/or Type 1 and 2 Streams. Response: This project does not meet the threshold of this Special Requirement. Special Requirement No.1 I: Geotechnical Analysis and Report. Response: The geotechnical analysis and report for this project have been waived per the City of Renton. 12564.003.doc I I I I I I I I I I I I I I I I I Special Requirement No. 12: Soils AnaZ)'sis and Report. Response: As mentioned in response to Special Requirement No. II, the soils analysis and report have been waived for this project site. I 2564.Q03.ooc • • • • • • • • • 3.0 OFF-SITE ANALYSIS I • • • • • '. • • • I I I I I I I I I I I I I I I I I I I 3.0 OFF-SITE ANALYSIS No off-site analysis is required for this project site as the site discharges almost immediately into a 7·foot by 5-foot reinforced concrete box culvel1, which discharges in a northerly direction towards the end of the airport and directly into Lake Washington. The City is well aware of this downstream drainage course and it is more than adequate to convey the runoff from this project site, which it does under existing conditions that are matched almost exactly to the proposed conditions as far as land covers go. 125M.OOl.doc