Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
MISC
PRELIMINARY TECHNICAL INFORMATION REPORT Vuecrest II 102 d Ave SE & SE 186" St. Renton, Washington PRE14-001189 Prepared for: KBS Development Corporation 12320 N.E. 8th Street, Suite 100 Bellevue, WA 98005 January 15, 2015 Our Job No. 17254 0. scy �P of WAsy 9 cn y 44733 e 013 T til A(A L t 1 /1 �5�2015 ¢ry14 A S� W CIVIL ENGINEERING, LAND PLANNING, SURVEYING 1821572ND AVENUE SOUTH KENT, WA 98032 (425) 251-6222 (425) 251-8782 FAX o z BRANCH OFFICES • TUMWATER, WA ♦ LONG BEACH, CA ♦ WALNUT CREEK, CA r SAN DIEGO, CA www.barghausen.corn Cr�HG ENGt���� TABLE OF CONTENTS 1.0 PROJECT OVERVIEW 1.1 Technical Information Report (TIR) Worksheet 1.2 Vicinity Map 1.3 Drainage Basins, Subbasins, and Site Characteristics 1.4 Sails Map 1.5 Assessor's Map 1.6 FEMA Map 1.7 Sensitive Areas Map 1.8 Boundary and Topographic Survey 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Analysis of the Core Requirements 2.2 Analysis of the Special Requirements 3.0 LEVEL 1 OFF-SITE DRAINAGE ANALYSIS Task 1 - Study Area Definition and Maps Task 2 - Resource Review Task 3 - Field Inspection Task 4 - Drainage System Description and Problem Descriptions Task 5 - Mitigation of Existing or Potential Problems 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN 4.1 Existing Site Hydrology 4.2 Developed Site Hydrology 4.3 Performance Standards 4.4 Flow Control System 4,5 Water Quality System 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN 6.0 SPECIAL REPORTS AND STUDIES 6.1 Black River Basin Reconnaissance Report No. 14, prepared June 1987 7.0 OTHER PERMITS 8,0 CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (CSWPPP) ANALYSIS AND DESIGN 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 10.0 OPERATIONS AND MAINTENANCE MANUAL 17254.001-TIR.doc 0 1.0 PROJECT OVERVIEW The Vuecrest 11 project is a proposed short plat, consisting of 8 lots. The site is located on the west side of 102nd Ave SE, near the 102nd Ave SE & SE 186th Street intersection, in a portion of Section 32, Township 23 North, Range 05 East, W.M., in the City of Renton. The project site is 2.45 acres in size (or 106,680 square feet). The property consists of one tax parcel (Tax Lot No. 3223059097) and there is one single-family home located on site (east side of property) as well as several associated outbuildings, utilities, and private gravel access drive. A majority of the property is a forested area (covered with mixed deciduous/coniferous trees; please reference the Tree Protection Plan prepared by Washington Forestry Consultants, Inc.) and a small wetland located in the northwest corner of the property (Category 11 Wetland; please reference the Critical Area Study prepared by Wetland Resources, Inc.). The site generally slopes from the east to west (approximately 35 feet in elevation change), with a slope averaging from 1 % to 2%. However, in a small area in the northwest corner of the site (near the on-site wetland), the topography increases between 30% and 35%. Per the project surveyor, there are no slopes on site that exceed 40% (as defined in RMC 4-11-190, Slope, Protected and Slope Sensitive). All significant trees on the site have been surveyed (6 -inch diameter at breast height [DBH] or greater) and are shown and identified on the Tree Retention Plan prepared by Barghausen Consulting Engineers, Inc. The understory cover is mixed with Salmonberry, Vine Maple, Western hazelnut, Sword fern, Salal, Oregon grape, Pacific Blackberry, and portions of the property have ornamental landscaping and grass areas (around and near the existing residence). The on-site soils consist of approximately 4 to 18 inches of topsoil overlying native soils consisting primarily of medium dense to dense silty sand and sandy silt glacial till deposits which are one of the more common soil types in and around the City of Renton. Please see the Geotechnical Report prepared by Earth Solutions NW dated December 15, 2014. As discussed earlier, a small wetland is located in the northwest corner of the property and is classified as a Class II Wetland requiring a 50 -foot buffer. The proposed project is utilizing buffer averaging to allow for the construction and future extension of the on-site public roadway (proposed Road A). Please reference the Critical Area Study prepared by Wetland Resources, Inc. dated December January 5, 2015_ Access to the site is from 102nd Avenue S.E. (residential access street). A public road will be constructed to provide access to the 8 lots, and will be extended as far north as possible so that the neighboring property to be developed by Harbour Homes (Vuecrest Estates; City File No. LUA13-000642) can extend the roadway for secondary access. The project site is surrounded by existing single-family subdivisions with similar densities; however, along the south property line there are larger single-family lots (due to topography) that range from 1 to 2 acres in size. As designed, there are approximately 690 lineal feet of proposed on-site public right-of-way (half street), which will have 32 to 39.5 feet of public right-af-way with 20 to 26 feet of paving, curb, gutter, planter (8 feet wide in portions), and sidewalk (5 feet wide). The project development will utilize and extend existing public utilities through the project site (water and sewer provided by Soos Creek Water and Sewer District) along with storm drainage and dry utilities (power, telephone, natural gas, and cable) serving all lots. Sewer will be extended from the Plat of Vuecrest Estates (City File No_ LUA13-000642) to the west property line of the Vuecrest II Short Plat. Please reference the Conceptual Utility Plan prepared by Barghausen Consulting Engineers, Inc. for more detailed information. 17254.001-TiR.doc In order to construct the project as generally depicted on the preliminary grading plan, approximately 2.05 acres will be cleared. Approximately 7,600 cubic yards of structural sail will be cut for grading the roads and lots. A majority of this cut material will be used on site to construct the project to the final design grades. Any excess structural material will be exported from the site during construction along with any excess topsoil. These figures are approximate and will be determined at final engineering design. Stormwater runoff from the Vuecrest 11 project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). The project is located in a Conservation Flow Control area (Level 2 Flow Control); however, as noted in the TIR prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, due to a connection through the downstream system the project will adhere to Level 3 Flow Control requirements. A Technical Information Report (TIR) has been prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, dated July 15, 2014, which will be updated during final engineering design to include developed areas from the Vuecrest II project. A Level Two Downstream Analysis was also prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, dated July 15, 2014, which will also be updated during final engineering design to include the Vuecrest 11 project. 17254.001-TiR.doc Figure 1 - Technical Information Report (TIR) Worksheet KING COUNTY, WASHINGTON, SURFACE, WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Project Owner KBS III LLC - Kohn Taylor (aka - KBS Development Cord Phone 206-755-5404 Address 12320 N.E. 8th Street, Suite 100 Bellevue, WA 98005 Project Engineer Bryan Schwartz, P.E. Company Barghausen Engineers Phone Part 3 TYPE OF PERMIT APPLICATION ® Landuse Services Subdivision I Short Subd. 1 UPD ❑ Building Services M/F I Commercial / SFR ® Clearing and Grading ® Right -of -Way Use ❑ Other Part 2 PROJECT LOCATION AND DESCRIPTION Project Name Vuecrest 11 Permit # PRE 14-001189 Location Township Range 05E Section 32 Site Address 102nd Ave SE & SE 186th St_ Part 4 OTHER REVIEWS AND PERMITS ❑ DFW HPA ❑ Shoreline ❑ COE 404 Management ❑ DOE Dam Safety ® Structural Rockery/Vault/ ❑ FEMA Floodplain ❑ ESA Section 7 ❑ CDE Wetlands ❑ Other Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review Full 1 Targeted 1 Type (circle one): Full 1 Modified ! (circle): Large Site Small Site Date (include revision Date (include revision dates): 1115115 dates): 1115115 Date of Final: Date of Final: Date of 2005 Surface 'Vater Design Manual 17254.006-TIR worksheet.doe [81131,'061 1/1105 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: Completion Date: Describe: Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan: Sops Creek Special District Overlays: Drainage Basin: Black River Stormwater Requirements: Part 9 ONSITE AND ADJACENT SENSITIVE AREAS ® River/Stream unnamed stream ❑ Lake ® Wetlands ❑ Closed Depression ❑ Floodplain ❑ Other Part 10 SOILS Soil Type Slopes AgC 6-15% ❑ High Groundwater Table (within 5 feet) ❑ Other ❑ Steep Slope ❑ Erosion Hazard _ ❑ Landslide Hazard ❑ Coal Mine Hazard ❑ Seismic Hazard _ ❑ Habitat Protection El ❑ Sale Source Aquifer ❑ Seeps/Springs Erosion Potential Moderate/High ❑ Additional Sheets Attached I 2005 Surface Water Design Manual 17254.006-TIR Workshect.doc [8/3/06] 111105 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE ❑ Core 2 — Offsite Analysis ❑ Sensitive/Critical Areas ❑ SEPA ❑ Other ❑■ ❑ Additional Sheets Attached LIMITATION 1 SITE CONSTRAINT Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: name or description On-site areas discharge to unnamed stream Core Requirements (all 8 apply) Discharge at Natural Location Number of Natural Discharge Locations: I Offsite Analysis Level: 1 1 2 1 3 dated: 1115115 Flow Control Level: 1 ! 2 ! or Exemption Number incl_ facility summary sheet Small Site BMPs Conveyance System Spill containment located at: Erosion and Sediment Control ESC Site Supervisor: TBD Contact Phone: TBD After Hours Phone: TBD Maintenance and Operation Responsibility: Private I Publi If Private Maintenance Log Required: Yes ! No Financial Guarantees and Provided: Yes 1 No Liability Water Quality Type: Basi 1 Sens. Lake I Enhanced Basicm 1 Bog (include facility summary sheet) or Exemption No. Landscape Management Plan: Yes ! N Special Requirements (as applicable) Area Specific Drainage Type: CDA/ SDO 1 MDP/ BP/LMP/ Shared Fac. /Nonel Requirements Name: Floodplain/Floodway Delineation Type: Major 1 Minor 1 Exemption 1 Non 100 -year Base Blood Elevation (or range): Datum: Flood Protection Facilities Describe: Level 3 Flow Control Source Control Describe landuse: NIA (comm./industrial landuse) Describe any structural controls: N/A 2005 Surface Water Design Manual 17259.006-TIR Worksheet.doc [813/06] 1/1/05 3 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oil Control High -use Site: Yes ! N Treatment BMP: Maintenance Agreement: Yes / No with whom? Other Drainage Structures Describe: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS Flow Control MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Water Quality AFTER CONSTRUCTION ® Clearing Limits Off-site Vault ® Stabilize Exposed Surfaces ® Cover Measures ® Remove and Restore Temporary ESC Facilities ® Perimeter Protection ® Clean and Remove All Silt and Debris Ensure ❑ Traffic Area Stabilization Operation of Permanent Facilities ® Sediment Retention ❑ Flag Limits of SAO and open space preservation areas ® Surface Water Control F] Other ® Dust Control ® Construction Sequence Part 14 STORMWATER FACILITY DESCRIPTIONS Note: Include Facilitv Su mary and Sketch Flow Control Type/Description Water Quality Type/Description ® Detention ❑ Infiltration ❑ Regional Facility ❑ Shared Facility ❑ Small Site BMPs ❑ Other Off-site Vault F] Biofiltration ® Wetpool ❑ Media Filtration ❑ Oil Control ❑ Spill Control ❑ Small Site; BMPs ❑ Other Off-site Vault 2005 Surface Water Design Manual 17254.006-TIR Workshect.doc [$13106] 111/05 4 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTSITRACTS ® Drainage Easement ❑ Access Easement ® Native Growth Protection Covenant ® Tract ❑ Other Part 16 STRUCTURAL ANALYSIS ❑ Cast in Place Vault ® Retaining Wall ❑ Rockerya 4' High ❑ Structural on Steep Slope ❑ Other Part 17 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 attacqeq Technical information Report. To the best of my knowledge the information ded here is ac at 2005 Surface Water Design Manual 17254.006-TIR Worksheet.doc [813106] 111/05 5 1.2 -Vicinity Map 198th St ? 5 37th PI 515 Z a 16 � 538th Ct e s m Se Petrovitsky Rd 00 V S r N J :r Oo T w, m �° , S 200th St 41st St Valley n a:< 4 ; A s s s Medical M L ebL r It Center Se Carr Rd 000 fp 0° S S 202nd St S a t 5 1 5t 5 43rd 5t £ .0 5e 180th St "03rd St 5e 180th PI V, M Chestnut a O0 a h y w Ridge Park tiR z Se 204th 51 �o Se 182nd 51 0b 16 5e 183rd w Zr c rb `y 5 47th St N v+ A s SITEe ro a r -5e 186th 5t She" „ 6 Se 1$7th St a 5 50th PI L_ T D St \, � 5 52nd St Se 190th St �Y 5 53rd PIo N r� S 192nd St p Se 192nd St Se 192nd St H 4 +L d T p O _ L N 3 — N w Se 196th St 198th St $ a 16 Io IN s 00 V S r N y :r Oo T p m �° , S 200th St _ 4 Q s M 000 fp S 202nd St S S 202nd St S a v £ .0 "03rd St V, M Chestnut a w Ridge Park tiR Se 204th 51 �o 0b 16 Zr c rb N v+ A ✓ S N REFERENCE; Rand McNally (2014) Scale: Horizontal: N,T,S. Vertical: NIA +C014AO0 18215 72ND AVENUE SOUTH KENT, WA 98032 II1 Z (425) 251-6222 a (425)251-8782 1 ro v CIVIL ENGINEERING, LAND PLANNING, SURVEYING, ENVIRONMENTAL SERVICES P:1l7OOOsll72541exhibitlgraphicsll7254 vmap,cdr Se 200th 5t 7 515 VUECRESTII RENTON, WASHINGTON Title: VICINITY MAP panther Lake Job Number 17254 10!24!14 1.3- Drainage Basins, Subbasins, and Site Characteristics M u m 4,1 :,WW, 6-Pf1•ja-KZil�Jnu11°'PJd1YSC1l\�wocll a'oe N+�N3 aay� 9-173-177 a1°q 533IAa35 W1N3rIN01JIhN3 'DNIA3A.df15 II ,LS ��I2A 90086 bM ' nn�P-13a P pn >1. v!ry 'SNINW]d ONY "MN13NION3 31A17 A ryp 3 '�. o", ! loai},aA yy, Pa•waay o L�O� ool ainS �1DDb1S H1S DN QZCZI xv� zsce-15z(szr} Z6 ��b,s o- y 14rvor,oH -1g1—` °.0,4 ZCO26 VM '1N33 Z a� rgzl—1 NV -18 DJb NI del© (INV :?NlGb �iJ J �J dN1Wll�l�d N411b �IOdEiO0 1N�WO-�n�❑ SBI < Hlnos 3nN3na alvzc 51zg! �S 4 :Ao :a1�1 = �a � s swe Qa°aso4 �? + I ` I W > I ------------ COfI3 I T W W J f 3 00 r ------------ w� S gS 3I NOA (3WOF NIYIYN3IYM x3 •.. _ I-•, •� * o --------------- _ - •1 r 10-B9B9-1�3 00 911119 � a '/ 1 � „-. � -1 a I 'I I I - ( 111 II f .� •i I ccr I , I - Ic w. •i : n IJ N , N a c> 1 •r; m 22 W Z — — ' w I IL I •C I•� �i (wi� oF K ]� <<) [ q w -J Lu z ?l I 1, W i _ C'7 Z , ctrl OIL m Q I O V n� rj, T z s o Tro �m I 1 I O �z C<,) a .y Z. 0 r f+ O`Qi •C o F- U � � �i W 0) z LL �o� 07 W Q awo �y 0 U Z U- 0 z Q Q IL a ! * n wn q lj -1✓IM1a r3 � � , I , I II � I I 1 I1 I ` nmNy � a< 5. I -.'1 i 4kY713M BC JN11 M/tl '� m 22 W Z — — ' 1 , •C I•� �i (wi� oF K 1 SPK } w�ra M1 i i i Z � r �1^ [ q w -J 1, W F W m I O V 90 N ? ` nmNy � a< 5. I -.'1 i 4kY713M BC JN11 M/tl '� 1f...' 22 W Z — — ' 1 , •C I•� �i (wi� oF K 1 SPK } w�ra M1 i i i Z � r �1^ awG W�5 a � ' � -J ? ` nmNy � a< 5. I -.'1 i 4kY713M BC JN11 M/tl '� 1f...' 1� I, ... _ _ _ _ - - - _ _ _ - - S -� •C I•� �i (wi� oF K l�i •y4 Y �1^ l IV ? W F W m I l dlulN uaJauae . ABYdNnPH IVIJ' � i - ,SZ'L91 3,92.01.1 1� I, ... _ _ _ _ - - - _ _ _ - - S -� •C I•� �i (wi� oF K ___________________________] } I I l IV ? W F W m I M I 1 I O u) C:- ,. I I I i• 3NIl kl �a o YJ.. 111 �y� 4 00 :o ..... 13s wI ? II ------------- n % U r qaq lo;b� . ABYdNnPH IVIJ' � i - ,SZ'L91 3,92.01.1 :) _m oEl �qll S -� •C I•� �i (wi� oF Jr; Z 3NIl 9 L7Yk11 � a� aa� 1.4 - Soils REFERENCE: USDA, Natural Resources Conservation Service Scale; Honzonlal. N.T.S. Vertical. N/A 4��ACl 1821572ND AVENUE SOUTH +Q- ► (� KENT, WA 98032 (425) 251-6222 a (425) 251-8782 P:1f7000s1172541exhibillgraphicsti7254 sort.cdr LEQEND: AgC = Alderwood gravelly sandy loam, 6-15% slopes For: Title: VUECRESTII RENTON, WASHINGTON SOIL SURVEY MAP Job Number 17254 10/24/14 1.5 - Assessor's Map REFERENCE: King County Department of Assessments (Nov. 2012) Scale: I For. Horizontal: kTa Vertical: WA R- 18215 72ND AVENUE SOUTH f\ KENT, WA 98032 (425) 251-6222 . (425)251-8782 U CIVIL ENGINEERING, LAND PLANNING, SURVEYING, ENVIRONMENTAL SERVICES P.-117000$117254IL-xhibittgraphics117254 amap.cdr VUECRESTII RENTON, WASHINGTON Title: ASSESSOR MAP Job Number 17254 1.6 - FEMA Map cn CITY OF RENTON _ KING COUNTY CORPORATE I i SITETT i r �{ J 1 t\ U) t1 ZONE X 1 L 1 32 a CL 1 o w U Z 1 z U S LOCATED WITHIN rOWNSHIP 23 NORTH, I f I 1 sourH;=rs; ,32ND KING COUNTY UNINCORPORATED AREAS 1 530071 r, CORPORATE LIMITS it �,. LEGEND L OTHER AREAS ZONE X Neu debet fined to be Dues& 500-year f Ik+odpwin I CITY OF RENTON REFERENCE: Federal Emergency Management Agency (Portion of Map 5303300987 F, May 1995) scare: For. Job Number Horizontal: N.T.S. Vedicaf: WA VUECREST II 17254 g.9"'AGS 1821572ND AVENUE SOUTH RENTON, WASHINGTON KENT, WA 98032 Z (425) 251-6222 tide: _� (425) 251-8782 FEMA MAP �,4<r e� CIVIL ENGINEERING, LAND PLANNING, 1-0 x"6,4.4 SURVEYING, ENVIRONMENTAL SERVICES DATE; 10124114 P:117000s1172541exhib tlgraphir-s417254 femaxdr 1.7 - Sensitive Areas Map I— I County Boundary SAO Steam X Mountain Peaks ® Cwt highways SAO Coal We Chs2Prrann%v Streets .00/ / Cow 2&* -d Hgo" f;/ CUM Arlrr* LF+rpF�iipA Lacad O Lakes and Large Pavers Parols n: Streams REFERENCE: King County MAP (2014) Scale: Honrortral. N.T.S. &14A�j Ir w►I b' Z 3 ? tr''�a tr.c+M€6P Veitical: NIA 18215 72ND AVENUE SOUTH KENT, WA 98032 (425) 251-6222 (425) 251-8782 CIVIL ENGINEERING, LAND PLANNING, SURVEYING. ENVIRONMENTAL SERVICES P:117000s4472541exhibitlgraphlcsl97254 suns.cdr Ukpnd ® SAO Wetland ® SAO Landslide SAO Coal We ® SAO Seismic SAO Erosion 2009 Color Aerial Photos (Bin► For. 2009 Color Aerial Photos (1121 n) VUECREST II RENTON, WASHINGTON Title: SENSITIVE AREAS MAP Job Number 17254 10/24/141 1.8 - Boundary & Topo Survey p-�rgmm r >^ nln c 4nn �ao�o n n N� .b O O m roN 7m'J UZmawn r,a I ID m NOI'13'26"E 2676.07' A O) 61 _w W m rn O c nuJ VJ� • L`! — 5338.04to un ' --- 33-0.51' Tar., �m IN n �= I CD n��� co rnZ MZ mz mz r.n!71 1!clirn , rB I 11 11 11 $1 11 11 11 Il ,w ` T nI n to LA w [ y w Q7 w Mw Q'1 w q1 r..� cz,w W 0 w P r1] O 0 OLP !•./ ¢ f n W - ow?I CP M Ln 0) W w j Ln --A LA1l 00 00 M a� v I L;J m� w rn I a u J, I--- to W 0 oA o ru' R)' 03. D7' C> 1 336.06' _ 672.12' _ J W - ru • O Ln Ln CO a u W (D 0) 4D ry NOV16'40"E 1344.24' I rn-4 cru rnu1 Z. 1 w O M to 1 `° 01 �I con aM M> oM 0 I W p rt1I >� Nom, D �I LnI I �+ Ll, �1 f350.44' "675.22' 1 675.22' 1 O N01'19'53'E 2700.87 ! rn sv ! n] rn rn L]} I O Ln I �j I` rU rL7 v Iu ICD a va Ico �rarvm � Nwa ru 1362.84' mvai� � w Im Yea Z— 7 Iry13--------------1362.84----------------------------- x rn — — — - — — 2759.32' w N01'26' 12 E 5485.00 ru R) bnr to Ln n cn 1 w rV N WSrMT, ~� �4 W a v I A w a vzn g /� O Id fM r�y v V wG1 1 v li II 1: fi IE ii H II kl II II U'd -, M M cn -0 -< M _ 1' .£ n to T1 (D m ar d « o r✓ c v IL IL o CL rr rt -3 rt n c IL` �• 0 Q 7 rD rD an a ❑ 0 Cr n E N -7 7 �' rt L' OLo CQ rD w -� zr rr fn 7 c ] Lf; IZ_ C. rt rD 0 T rD m C. :. "L1 < n j f 5�: :z O n rD D n ? L n u n 0 o U. .,J rD _. IT cl L0 u: Ln •i - a o M II (DCD a �- mm C� I o Lr I �� �_ _ Par, rl „ P h2 �, ! ���I''c) TI` rl1 0 nil p�' rot' c5" `,I )-A l V peril ° C" C 4, C C�rO rl r'1 1 �� -U I f C-1 C]� Lo 0(3 'Coop 7 C S I L 1 ��.� - I CD m o N01 '13'26"E , 2676.A7.' ��d r w o 4] g�- a Ln N 1839.80' �'N nm i I VTF'� 6 15'r T 6690 ^---8gWp CnLOCnTUn 1 onmooL I : ! y �g <DnLnf mvzo I / cn i y m a nm I Oy, m } y dti y. ti d O�rn(/7 �I / mn!�F�il m n' 2 0°` ( I i m I •�DA n f �n morw silo m w N� L0 m =-I k i m` 1¢i v Z>' C i- wmr-i °: ` °� Nm�-4n Ve1ci 1 } 2X w n ca a -, w DR3o 1 \ n C m w �mw= o p i �r �zrnw >33 z "� p o b' m r m�ru� M om' D ?} � ��Om \\', + yfh G) DZO o--Iz �, na m� N ¢`'o°1 �\\ \r f0 +` pTOF• �aCF o mDm w�Z co z LO G.7 Z3-. ,1 \qN .max m, w fl Z 33 G) L71 4"1 ° ..1� N .,vrZ�,, w L� w M 0 r z *Mm r„ - [� r:1� m(n m 'ci [j1 3 C? C] -A _ r-11 r T1\ \ me 3Zn Z -40 Donmm u-1-I--� OOC W M 0 Xm� r'j ncz O O_1 m0=nC CSS 71Z� wr-r_: � w3 -n U)ruwLor XM_rw WOODS m zM7. m mLn mwnmr <_<w �_r I Ln CO M �mG7 n Dm ➢ruD:c m =r-. 'c>M , :K nDD Ln o� Drna)m= -<Mm m�� wDrmwmO D � wcnrn m nU' r -I 10Zm Xc =r Pm rZrZ Z m X m0 = I -4r wD 370m I -Um-40C O mfu� m Xw Fr1 L7_4 U1C cnLn 00 0 m 3 OPm Z --43 =_4w D �rn wm (0-nLn Ln Gl �m uZ --I -Cm nC�=Z m••< z O O w 1 D33Z nw••4 Ln z Ul• rnn L7 M-a�wnn_ � 30u r -M mCm D �__ =w--"rC m00 O ww (DO m LJ7m ]>"M m0 Mn >c�m m ZO mnl-•, TI m-0 rnD znm33O LD M m -4Z070 mD r=-•1wzrc0Z r -IP -I D Mw zMwmD -4M ➢ � DZOmm� L»pm m Ocm mcn ten= >0 n D � 033 n w Y 33zr 3m �433n C D -4C0 Ln VM o = __4nn m cc omz MLnm23-4r rt• =RJw D 0-1cz-am m� z D-<DOw 0(71z O z mG7nrn coDC-4 UlU7rzrU7 � a z SCmDr aw=m_ ww= z0a) m -0 Ln n a 'p 23Ln0 Ulm-4nNo r _9 = ��nn10 (712 mwLn ;w w:E SNm _n m IT oOm IMM S SOZZ mc m D o ru m 0 Ln U3 r m m w G1 D r n m r.71"p 0 n lU w = M Ln m G) Ln TI rslw-r -4 o nz37 on o =-+-0M__4nO Or --n z z w ua X00 U7r•-In D ZOm4 ru_<_413 h. r- Z30� __q_zZ� NZ = n O =� z X. mn=� ru Ln Ii 37 -nm w w Om rn m a0 O •--13 M>X m Dmm� O' ' 3�z =31 DCa Lnr �s'm U) u Ln 3 3+-I Cn am: mw� �wwm r- -n w m w -4 O 0z n z c') > Ln wH � D z--4rD OC zG7m zm Cnww OD r- m Ln OXr41z nrnx On C" -.i m c m o __4:KCw n331313 m MO 33 n z 33 MM IN Ln D -4 w Ln r1 •a m o�mD z LP __4 03�7zzMX: -n r_ m o O mm O-4 w Lnz�-G-)nn mz 33 1-100n TI w0 O 0 L n0D XMM0 n r -Z O \3z �m � IT w0�3) __IO mmD mon D = D Om 0 2Z � zLn� n � m -0 zM-nm I 0 m= XG7-4m-4n =D m D 170 Lr) w Cw DCDZSTO "M � z r-ZO "Ln nr� m3 Ln n r-4 O OZ p n r -r 0-0 O -4 r -r a 0 m Ln D n Or - L0 rLn D r n m z Z I -r 0 *-r H0 m c r- En n� r (n w r 0 MM w= mZ D n J} �m cl m 33 w mo m O D --1 m O TI Ln m l-•1..•, n M G7) o -11 _4-_ � w n n r c) I ,-I w m M Ln o� ►•--) r -M0 rzZ0> C4 33• n= z1-Im�0>13 w Ox mm_1= `J M C� m 1) Lr) (D oonn. nrn zzw cm �n m � Cuzco CTIn m clD��wOr-4nCooO -4rn w�� >(D0 nDONZoo O >"Zmm =D Ow=z -L ru �OZN OLODm1-0033oDMZ m-4 I-'IOmo I-IZu wznfl OD OOWmZ -G7�0 �"'I' n DZ D 0 o0 = O-•4230 I"" O.LOw--_� XM JD M13 Z Z� z z m" 0 wflTlzwruiw -ZG1-4 �O w0= (n LD O__4 Ln I]1 � ' O m RJ n TIS D RJ D W' • t' U1mmm �]} �Pu Co— - Omw• D� w �Z Fr2 0 33 n O O ➢ C3• u u M Z 0 O r -r r -I z r-4 = n lJ Omm CO2�C ~' Z O C1"m� D LD 1� G)0 Z�r rt- mcn 03>Z nz0� Don ZED X 7c mm N 4 acro mnO=>0"X G,)>m -1 w-4 Ln Ln O o (3)Un7C wLn25m�r mozwr-wm zo o 0)I --I Jm wn, 8 wwU1DmTO � O-< OZ m -Tl U•1 C) )•+' Dr-I�ODSD w Tlw Zo mLnn Mzz m0)Z= ZI••+U10ZC (D z nLnC- rn0m0 CD (� �U1Cnn m(nmG1� :E G) 0Tn= �C� m• ZD �-+ f [Dm�O __40 n CwDm � OD i-•+ w03D O�ruONOZ -[-4 Z-0� __�-D(n m M71MMWr-Imz Z -4 MZ m2 u-4 Ln onmOOrn (nD ,n m _<rUDC.7 D za= Z ww zn0(nr +"}' 33 ' W D Ln n0 0 �OOZZZO �O !r m 0-4 -4X CC1Lnw O 'n 4nO37nn>M ( o �z-Ti= o• I-ILn -A •-+D��o�a m >0 on gy=m mom=cmr � Ln coD LD m =m0�Ln=' �Z S�=D C71 CD Ln m �= =�Zm w w=mr -4 O� c)MMfni]mm00 Z• _l =F• -I _TI 1> oD man DDU3 = 0 I I z 3 23w-.4"zMzzn�r-I r -I -4D00 Ln -i L0 _U r-0=ZMM00r-=� z OnCm �m Om 0 mC r-4mD0 r -I ZZ� DD co Ln mmn �nNc) u "91=� mLn -4 nncn3JO>0T7Oz O mom= mm S OnmLncz XZ 4 N mm �n mX OrDmZ mo"Mz z L�4n ra nn Dm oODcLFI G) 0 �Ln r. (n I 0 ro ncomm� m o O 71mT1�-1-433 O(n D >01Z z 1 ZnC Oc �X0-< C U)C•--I r --v ]>nmw TOm>MM m �n2 lD-•I�r0M mDLn0� Z 33X: rug.-•• MO �mO "m c --IM Zto MM = m�nnzX m XmLn OLD n =OTn wD' w m00--4M-mD-D-4 r Ln - 0_133=(J1 LD Zr mGl rOO � M Dma(D M—mm Dmc D rn ow DM. U) X n m Ln n Ln LD'-- 0 m D m = gym• p n � � O r-, n O iD -n -4 m 7: OLD L0 m D Z Zr�Jr M ru C M r CJw�3r �'r lf, - �m`jxx yn�\••, Z\=-�. M Ln Z m1"= '' \ P'w m a o NZO m zz �+> u�~SN�� XX_ fu c: � n oy oars� ax A n �II rn v\m �• fr1 tL..J Pry �`.W ♦�a C� fl �Cn2 a r ma N Z OF VO v a a v T¢ ro MIX w ru�w m rro m ar% m� Z D W' Z x T T v a� Z�� M c a ✓ m s 3. m 7i�iniY'� a 0 u1 z Mm Z • r _ •., iJ UI r n! \ 3:� 0m �";Wob M. 0 tnaT Ln mm (n 2 n m LJ RJ r F� v iu v A ® T w` Q W a fr*1 Q 4wJI N v a m T an0 ry^. m s m V, v z �� b T T r,I 1 sn MAPLE mm•,w a �`o• `-'warn t �: rr r,1 Toq 0 r'1 PJ r_11 r- _ r'� O • �� a Ty b� A C7 .1! C7 C] n n' r.�r =�,�r+30" TWIN .DFi7 AL6En F [Si^ C7•> p �m a' {! 015' ALEIER �2 11 r' rn R M rn D7 LM M1 n W a wnr X '. _ m co u, o1N rn' ti rn 7- 4r . LD l ! M m \ / b �y o O N LU z a M z Cl C.n N# N N f r r LTI ' m o o r a Ln a t — — — — w N a .- � 0 1 0 D z nm > C, rn J 1 0 j r r�i c °I i rn z �U)� <-r,i en .. °Z° I�nr , 1 dI3 .Y2 r�, —� S� v�1T 17�m r, rn z 1ilj -bE a 33 W n Cy Q 330 .,210 !v Z Lr)� l r, -z' Z m ar z z M O m Etlj .2E oLnm -' U1 -0 w N mN m'� mN mn� N -nn 14 on rn>,m A on o 0 0 8I3 -0E 8 svmn nv z� mX ma m coxW�'w xl 2 y�jn A. Ji :LO LOTXMM �n 'c �c c o°c \ ma^ m^ 030.0' 8 e n m r \ ac ^? N N 0' 0 IWn n ry n In m 40 f w I r ca z� F i N2 FIR / o '.168.O1uF9 rl`f� e)}/ rn a s o _ _:• _ "D.,� --ted --rV - '- ��n— m NOI.16]40'•E 504.09' — _ �I 102ND AVENUE'SOUTHEAST _ \ NO 1 ' 16 ' 40 "£ 166.03 o f Z' (MAIN AVI NO E SOUTH) \ NOI'J6'40"E 672,12' ----- - F CSG _ `� FL VERT. CSG o enc �--� SI WALK ° FL VERT. CSG SIDEWALK rp +u i — — — — — — — --� nnz n S �-'vT------- rKN� a �pms�n ° mLO a omW .r* nn roti 1� �L'0 � /gip 7 ZU rom irz-sr aw ... rvam r 0 C3 ?� T:mm 2 amaz -3 rsa coma smi,m � ° O W f9V ALN 2N f Om Xu � NN➢Q I 01Z1M~fib NNS m C7 1 UI r+33 M I Qvo V, In llI `n { nnLnn I m nm o Fm0ILY7 I TTS V Orr I•� I i. o' F In O N Lr cn C rG :0 :0 t3 w n co t3 a M x c av SHEET TITLE: REVISION DESCRIPTION DATE BY a rJ 0 a 0 5 r7 tv X T T1H �T+T_�H. 4909 MAIN AVENUE SOV Q`1'0�MAS#� hD I ADDITIONAL TOPO AT NW CORNER OF SITE 11/05/14 JK A Ln Ln Ln = z ' D W L cLIEi�T:KBs l r l A 0 o x E N GIN N EER 1 N G L L C m � 0 12303 Northeast 8th street, #100 Bellevue, WA 9soo5 F3 <i • CIVIL ENGINEERS ~ SURVEYORS -LAND PLANNERS ru O r CONTACT:Kolin Taylor �A„a _ _ 3309 56th Street NW,Suite 106 Gig Harbor, WA 98335 a-. a Phone: 253-857-'5454 Fax: 253-509-0044 info@contourpllc.com Ln ■ a 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Analysis of the Core Requirements Core Requirement No. 1: Discharge at the Natural Location. Response: Stormwater runoff from the Vuecrest 11 project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off-site drainage facility will discharge to the same downstream drainage course that this project is tributary to_ Core Requirement No. 2: Off -Site Analysis. Response: A Level 1 Downstream Drainage Analysis is provided in Section 3.0 of this Technical Information Report. Core Requirement No. 3: Flow Control. Response: Stormwater runoff from the Vuecrest 11 project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project_ The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). Core Requirement No. 4: Conveyance System_ Response: The conveyance and backwater analysis will be provided in final engineering. Core Requirement No. 5: Erosion and Sediment Control. Response: Temporary erosion control measures will be provided in final engineering. Core Requirement No. 8: Maintenance and Operations. Response: A Maintenance and Operations Manual will be provided in final engineering. Core Requirement No. 7: Financial Guarantees and Liability. Response: The project will provide a Site Improvement Bond Quantity Worksheet to establish a bond amount for drainage facility restoration and site stabilization financial guarantee prior to construction. Core Requirement No. 8: Water Quality. Response: Stormwater runoff from the Vuecrest 11 project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest 11 project. The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). 17254.001-TIR.doc 2.2 Analysis of the Special Requirements Special Requirement No. 1: Other Adopted Area -Specific Requirements. Response: The proposed project is not located in a designated Critical Drainage Area, Special Requirement No. 2: Flood Hazard Area Delineation. Response: As indicated by the FEMA Map included in this report, the proposed site does not lie within a floodplain or floodway or a stream, so this special requirement does not apply. Special Requirement No. 3: Flood Protection Facilities. Response: This project does not rely on an existing flood protection facility or propose to modify or construct a new flood protection facility, so this special requirement does not apply. Special Requirement No. 4: Source Control. Response: The project does not require a commercial building or commercial site development permit, so this special requirement does not apply. Special Requirement No. 5: Oil Control. Response: This site is not classified as a High Use Site given the criteria in the 2009 KCSWDM, so this special requirement does not apply and no special control treatment is necessary. Special Requirement No. 6: Aquifer Protection Area Response: Per the City of Renton's GIS Map the project site is not located within an Aquifer Protection Zone. 17254.001-TIR.doc 3.0 LEVEL 1 OFF-SITE DRAINAGE ANALYSIS Task 1 STUDY AREA DEFINITION AND MAPS The Vuecrest II project is a proposed short plat, consisting of 8 lots. The site is located on the west side of 102nd Ave SE, near the 102nd Ave SE & SE 186th Street intersection, in a portion of Section 32, Township 23 North, Range 05 East, W.M_, in the City of Renton_ The project site is 2.45 acres in size (or 106,680 square feet). The property consists of one tax parcel (Tax Lot No. 3223059097) and there is one single-family home located on site (east side of property) as well as several associated outbuildings, utilities, and private gravel access drive. A majority of the property is a forested area (covered with mixed deciduous/coniferous trees; please reference the Tree Protection Plan prepared by Washington Forestry Consultants, Inc.) and a small wetland located in the northwest corner of the property (Category II Wetland; please reference the Critical Area Study prepared by Wetland Resources, Inc.). The site generally slopes from the east to west (approximately 35 feet in elevation change), with a slope averaging from 1% to 2%. However, in a small area in the northwest corner of the site (near the on-site wetland), the topography increases between 30% and 35%. Per the project surveyor, there are no slopes on site that exceed 40% (as defined in RMC 4-11-190, Slope, Protected and Slope Sensitive). All significant trees on the site have been surveyed (6 -inch diameter at breast height [DBH] or greater) and are shown and identified on the Tree Retention Plan prepared by Barghausen Consulting Engineers, Inc. The understory cover is mixed with Salmonberry, Vine Maple, Western Hazelnut, Sword fern, Salal, Oregon grape, Pacific Blackberry, and portions of the property have ornamental landscaping and grass areas (around and near the existing residence). The on-site soils consist of approximately 4 to 18 inches of topsoil overlying native soils consisting primarily of medium dense to dense silty sand and sandy silt glacial till deposits which are one of the more common soil types in and around the City of Renton. Please see the Geotechnical Report prepared by Earth Solutions NW dated December 15, 2014. As discussed earlier, a small wetland is located in the northwest corner of the property and is classified as a Class II Wetland requiring a 50 -foot buffer. The proposed project is utilizing buffer averaging to allow for the construction and future extension of the on-site public roadway (proposed Road A). Please reference the Critical Area Study prepared by Wetland Resources, Inc. dated December January 5, 2015. Access to the site is from 102nd Avenue S.E. (residential access street). A public road will be constructed to provide access to the 8 lots, and will be extended as far north as possible so that the neighboring property to be developed by Harbour Homes (Vuecrest Estates; City File No. LUA13-000642) can extend the roadway for secondary access_ The project site is surrounded by existing single-family subdivisions with similar densities; however, along the south property line there are larger single-family lots (due to topography) that range from 1 to 2 acres in size. As designed, there are approximately 690 lineal feet of proposed on-site public right-of-way (half street), which will have 32 to 39.5 feet of public right-of-way with 20 to 26 feet of paving, curb, gutter, planter (8 feet wide in portions), and sidewalk (5 feet wide). The project development will utilize and extend existing public utilities through the project site (water and sewer provided by Soos Creek Water and Sewer District) along with storm drainage and dry utilities (power, telephone, natural gas, and cable) serving all lots. Sewer will be extended from the Plat of Vuecrest Estates (City File No. LUA13-000642) to the west property line of the Vuecrest 11 Short Plat. Please reference the Conceptual Utility Plan prepared by Barghausen Consulting Engineers, Inc. for more detailed information. 17254.001 -TI R.doc In order to construct the project as generally depicted on the preliminary grading plan, approximately 2.05 acres will be cleared. Approximately 7,600 cubic yards of structural soil will be cut for grading the roads and lots_ A majority of this cut material will be used on site to construct the project to the final design grades. Any excess structural material will be exported from the site during construction along with any excess topsoil. These figures are approximate and will be determined at final engineering design. Stormwater runoff from the Vuecrest II project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off- site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). The project is located in a Conservation Flow Control area (Level 2 Flow Control); however, as noted in the TIR prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, due to a connection through the downstream system the project will adhere to Level 3 Flow Control requirements. A Technical Information Report (TIR) has been prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, dated July 15, 2014, which will be updated during final engineering design to include developed areas from the Vuecrest II project. A Level Two Downstream Analysis was also prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, dated July 15, 2014, which will also be updated during final engineering design to include the Vuecrest 11 project. 17254.041-T I R.d oc TASK 2 RESOURCE REVIEW • Adopted Basin Plans: None available at this time. • Finalized Drainage Studies: This is not applicable. • Basin Reconnaissance Summary Report: The site is located within the Black River Basin, included in Reconnaissance Report No. 14, prepared June 1987, included in Section 6.0 of this report. Critical Drainage Area Maps: According to the Water Quality Applications Map in the 2009 King County Surface Water Design Manual (KCSWDM), Basic Water Quality Treatment is required. According to the Flow Control Applications Map (also in the KCSWDM), Conservation Flow Control is required; however, as noted in the TIR prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, due to a connection through the downstream system the project will adhere to Level 3 Flow Control requirements. Floodplain and Floodway FEMA Maps: Please see the attached FEMA Map (Section 1.0) utilized for this analysis_ As indicated on the map the site is located in Zone X and is outside of the 500 -year flood plain. Other Off -Site Analysis Reports: A Level Two Downstream Analysis was also prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, dated July 15, 2014, which will also be updated during final engineering design to include the Vuecrest II project. Sensitive Areas Folios: Based on a review of the King County Sensitive Areas Map Folios, the site does not contain any On -Site Wetlands, Erosion Sensitive Areas, or Land Slide Areas. However, through field survey and analysis it has been determined that there is a wetland on-site. A small wetland is located in the northwest corner of the property and is classified as a Class II Wetland requiring a 50 -foot buffer. The proposed project is utilizing buffer averaging to allow for the construction and future extension of the on-site public roadway (proposed Road A). Please reference the Critical Area Study prepared by Wetland Resources, Inc. dated December January 5, 2015. Road Drainage Problems: This is not applicable. United States Department of Agriculture King County Soils Survey: Based on the Soils Map (see Figure 3 — Soils Map Section 1.0) for this area, the majority of the site is located in the soils configuration known as Alderwood gravelly sandy loam. The on-site soils consist of approximately 4 to 18 inches of topsoil overlying native soils consisting primarily of medium dense to dense silty sand and sandy silt glacial till deposits which are one of the more common soil types in and around the City of Renton. Please see the Geotechnical Report prepared by Earth Solutions NW dated December 15, 2014. Wetland Inventory Map: A small wetland is located in the northwest corner of the property and is classified as a Class II Wetland requiring a 50 -foot buffer. The proposed project is utilizing buffer averaging to allow for the construction and future extension of the on-site public roadway (proposed Road A). Please reference the Critical Area Study prepared by Wetland Resources, Inc_ dated December January 5, 2015. Migrating River Studies: This is not applicable. City of Renton Aquifer Protection Zones: Per the City of Renton's GIS Map the project site is not located within an Aquifer Protection Zone. 17254.001-TIR.doc TASK 3 FIELD INSPECTION The field reconnaissance for this Level 1 Off -Site Drainage Analysis was conducted on January 15, 2015 for the purpose of analyzing the proposed project site and its upstream and downstream corridors. The weather was cloudy during the site visit_ During the site inspection, there was no evidence of stormwater leaving the site. 3.1 Conveyance System Nuisance Problems (Type 1) Conveyance system nuisance problems are minor but not chronic flooding or erosion problems that result from the overflow of a constructed conveyance system that is substandard or has become too small as a result of upstream development. Such problems warrant additional attention because of their chronic nature and because they result from the failure of a conveyance system to provide a minimum acceptable level of protection_ There were no conveyance system nuisance problems observed during the August 16, 2013 site visit. Furthermore, based on a review of the drainage complaints received from the City of Renton, there is no evidence of past conveyance system nuisance problems occurring in the direct downstream drainage course, as there is a record of none having been submitted. Stormwater runoff from the Vuecrest II project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). Providing Level 3 Flow Control will ensure that no downstream conveyance system nuisance problems are aggravated by the proposed project. 3.2 Severe Erosion Problems (Type 2) Severe erosion problems can be caused by conveyance system overflows or the concentration of runoff into erosion -sensitive open drainage features. Severe erosion problems warrant additional attention because they pose a significant threat either to health and safety or to public or private property. Stormwater runoff from the Vuecrest II project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). Level 2 Flow control is intended to limit the amount of time that erosive flows are at work generating erosion and sedimentation within natural and constructed drainage systems. Level 3 Flow control further restricts the downstream release rate of the project's drainage facility intended to prevent significant increases in existing water surface levels for 2 -year through 100 -year return frequencies and prevent aggravation of existing flooding. 3.3 Severe Flooding Problems (Type 3) Severe flooding problems can be caused by conveyance system overflows or the elevated water surfaces of ponds, lakes, wetlands, or closed depressions. Severe flooding problems are defined as follows: • Flooding of the finished area of a habitable building for runoff events less than or equal to the 100 -year event. Examples include flooding of finished floors of homes and commercial or industrial buildings. Flooding in electrical/heating systems and 17254.001-TIR.doc components in the crawlspace or garage of a home. Such problems are referred to as "severe building flooding problems." Flooding over all lanes of a roadway or severely impacting a sole access driveway for runoff events less than or equal to the 100 -year event. Such problems are referred to as "severe roadway flooding problems." Based on a review of the FEMA Map (Section 1.0) the proposed site is outside of the 500 -year floodplain, and there is no evidence of severe flooding problems encountered during our visit. Stormwater runoff from the Vuecrest II project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). Level 2 Flow control is intended to limit the amount of time that erosive flows are at work generating erosion and sedimentation within natural and constructed drainage systems. Level 3 Flow control further restricts the downstream release rate of the project's drainage facility intended to prevent significant increases in existing water surface levels for 2 -year through 100 -year return frequencies and prevent aggravation of existing flooding. 17254.001-TIR.doc TASK 4 DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS Please refer to the downstream drainage system table and map included in this Section. Drainage complaints were requested from the City of Renton and are included in this section as well. There were only two drainage complaints near the project site, and both complaints were filed more than 15 years ago. These complaints do not apply to the downstream drainage course from this project. 17254.001-TIR.doe TASK 5 MITIGATION OF EXISTING OR POTENTIAL PROBLEMS Stormwater runoff from the Vuecrest it project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off- site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). Level 2 Flow control is intended to limit the amount of time that erosive flows are at work generating erosion and sedimentation within natural and constructed drainage systems. Level 3 Flow control further restricts the downstream release rate of the project's drainage facility, intended to prevent significant increases in existing water surface levels for 2 -year through 100 -year return frequencies and prevent aggravation of existing flooding. 17254.001-TIR.doc S 1D ILWV" S£MMR s ld KLUDALUMM ■ r ■ r • r r r M 4w r • r r r s • .r .r r4 A MORRIS AVE S +4 0 s,M FutGMuwti~ ■ s 3AV KLWA KM • d r :cc v� d r ■ TALBOT P1. S DAVIS AVE S DAVIS PL S 0 9b ro ro co we O O &� l _ + i 363411 QTBUI 04 q�o U W 1!! � O � J � v L CL s ld KLUDALUMM ■ r ■ r • r r r M 4w r • r r r s • .r .r r4 A MORRIS AVE S +4 0 s,M FutGMuwti~ ■ s 3AV KLWA KM • d r :cc v� d r ■ TALBOT P1. S DAVIS AVE S DAVIS PL S 0 9b ro ro co we O O &� q�o U `c � u is: L � � a� o •� C � c� � a�"i a`i aL"i d0 3.a 3 o a s a o W y .� a = ' p p U 'C -6 'b ae > `ti' U 0 e O O O O r_ la ° o a C U C C �i U U U U U U Q ' 7S C •� j C � O C A O z z z z z z w a > m U > 0 0 p O $ u % C. QnrA A M ocA d Q Q ri IdLn Ln O O R C ei U ti u toT2cc �3 to � '� k R r ❑ N OL Q Q. CLIaw '� > d a, c� d a 6c U 3 Q i 1-w C g ,Q V a. y �z R SIDE ❑ ° L) 73 —Cd clcl O E6 a z C.41r to m I cn » ° �I � � _ � . — h} f � � tic }t -� •: ; Fr Js Picture #1 - Looking Downstream from Natural Discharge Point ' e'- _ r - -. ate_ - ' �-.,-�".`• � .�, .' - r r 00 E E. of cc y o 0 0 0 o 5L v z❑ z z - z z z _ z o a z z LLz ~ H a ap cn w v _= v V1 O Z d ID w CG CJ Y y ° 0 w w o z E a z a w c O O -� O C CD r o Q~ Q U U m O Cl v7'i ❑ O w w i Y VI Q a E O N co N w m 00 z Z o m o r u a N a o ❑ 3 E m ❑ a o z a z Y ura N a Y a C3 z n O a v a a w g O v �° mo g = z 0- z Y o_ M J z l7 _ U' W O w 4 a o o E E 01 3 w O �n Z 0 0 p r OJ Q y - w Q Z _ r � O. d 2 ce u Q r ✓� W d Q N w Q w Q 2 QQ w Y O S.7 in o w D: Z u0 ❑ z u Q0 a O LL LL p u .n m 4 z Q Z ¢ w O O LL w ❑ O V w Z yr O c Q a' Q "° O ❑ _O ❑ W K O O ¢ Q } LL O ❑ Z w O y \ O V LL O Or O O O } u a cn O 4 iC cr V C 7 v W �= m H r r z z a❑ o z a z "- a o � Z❑ ,Z o a QW O o Z LL m❑ Q w a } 7v, Z w _— al C W C M LL w w Z O cry v1 F ❑ l7 Y ❑ ❑ o_ w 3 `° Y N V y w Q p O Z, O w w Q om Q V Q a O O H ° 'm o 0 S a u K c[ a 3 O i s 7 a Q m Z H o- '�- m— V T r N d m 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 m M1 , ID O m N m N m N m w .a m O m N �n 7 'D ? T LO o Lp v w o LD o 10 v -D v LO fn %o v, ID t O N O m O m O m O Z 0 O 0 0 0 0 0 O 0 O 0 M1 0 0 4 4 0 Q 0 4 0 4 0 P 0 O o 4 a O 0 O 0 O 0 O m m m m m a m T m m T ry v v v v v v a v v a a a 0 0 0 0 0 m n m n w n w n as n ,� H C p .� H H H .-+ H H H V H H ey a H IH M N m ry m N m N m N M1 H M1 H M1 H M1 H M1 H N tO N 10 N N 'O N 1O N N N N N 1D N 10 N l0 N eqN T NN m T N m N m _ = W yr v, a a a w In v' w w ir, iri 7 cn vri vYi j -p oa Y r lD r �D r n r n r n ❑ r ID r iD r lD r �D ❑ N to N r n 2 ❑ ❑ r 0 ❑ r r r w w r w w w op co Z ca op as co 2 W o o r Z Z m Z O O O H v, � v, v, yr �n in N ;n � ''" H ''" m ''' m o_ 2 a 2 V, O O m m V5 '-' Vl cn ul cif ul �f, ''"� �D vwi ul H � .-� 1p •� m •� w X 00 T r r N N N .-a .+ .+ .+ m, V N X d 9a w w OD w Q V O m m m M m m H M1 N N N N l0 H N H "'� VI M H lD H w H w H M H w H m m ry m v ma Ln O n ID O co a n In n H m m m o m n m m m 0 m m 0 m q o O m o o, o w m O m a N o N 0 N a m a 0 = 0 m H 0 N m H a N 0 = 0 = 0, H o N m H O N rn H m H m � 0 0 Ul cif Q m Q 0 0 0 N N N T N W W Q N m M1 M M1 DO W N O O GS mo Q c!1 m lit O l0 10 O 00 +--� --� Q Q Q M1 LD N H m m Lf1 C m m o O N O O P O N P O N m m H m m H m m H p O N m m H m m H 4 O N m m H O O N O O N O O N O O N pp 6 N m m H O O N m m N p O N w m H m m H b N n M = JH, w wH m mH Tw TN 0 0 O O \m0a O 0 O m O M O 0 O O NL1 O O O N00 0 O \O O \C3 0- CL a. LL u m cc o_ o_ oe }p}' ac z oc x rt x �n u LL W V1 VI V V V U V LL J LL [Y LL LL LL LL LL ti U u u u LL E a J a U Z r s 47 w d z z z z 2 Z 2 z d Z w w m Q z d w 00 Q Q W o o c0. O s o i m 2 2 2 2 a u n 0 o c il5 W N tO ul n 4 N O N n N V, N .+ N �O lD .-+ n H m O n V et M1 w o T M1 W �D w f� ,--� N M1 O r- M1 QQ z E m o lIl o Q . n a n O M1 a m m 0 M1 0 4 0 O 0 DD o N g lD q P q q V a O q Lil o V, o ll, off o m M + w 0 m lD 0 V5 0 V5 0 G m 0 0 0 0 omo m m 0 m m 0 s 0 o a o $ 0 3 m = m U a, H o N o N o N o N m H m H m H 0 N m H m H O N m H o N 0 N 0 N 0 N N rl N N N H ri N W N m V �fl cD I� DO Ol o N ry m In r� 00 rn 0 r N m v v s +--1 ,-i -4 ,--I cq .-1 r -I c -I -1 -1 N N N N N N KING COUNTY WATER AND LAND RESOURCES DIVISION • DRAINAGE INVIESTIGATION REPORT T)C-P PROBLEM: J Page l: INVESTIGATION REQUEST Type ���1W,'�j tECEIVED BY: r . Date: �tr1 • 0 ' 1' OK'd by: T? FILE No. 67"f pg�f Received from: (Day) ( �) (Eve) NAME: ��i PHONE- �Z$�I ADDRESS: X15 �� � : ' 3V City iG+c�-�'Dn State Zips Location of problem, if different: CgTur Reported Problem: CALL FIRST 91 (Would Like To Be Present) }[� SCf�J l t.�tt Ybald wYU C&}{,� l/�W-F IrUa'7$i'1 YU - i ALL. �l t C.( -f0 E'er. 1 1I�1Q G' &WOl t�Vl 6 dale A - r� 4 -Ka, Y�i1'1l WI be tK5 u p 11 t i V ayw A -L PAA- 15 K . �1�4�1/i Jim l rT i FI cy� '�-1 ad ti-" `f -5 of � C cs . f �1tii j`(- C�L� Jn..! `�' 7 r'S`'r�c-.'Y! � S �•�c! U L c� �= 1j J �,fr /j•Ii,� �;ri <,.�'� ��+ t . , .. 217- C: f`;1/ c ��� � �•. � /,"'f � � . Plat name: Other agencies involved: 3 Z'�5 z3 I/a S T R Lot No: Block No: No field investigation required (initials) To BE COMPLETED BY COMPLAINT PROGRAM STAFF �I Parcel No. --3 l g044`T Kroll( e Th.Bros: New & 2& OZ Old 4( E,95 Basin Council District Charge N ... ............... ..... -.................... .................................................................. ........................................................................ I.............................................................. RESPONSE. Citizen notified on / SCJ by: phone letter in person DISPOSITION: Turned to on I I by OR: No further action recommended because: Lead agency has been notified: Problem has been corrected. No problem has been identified 1C Private problem - NDAP will not consider because: _Water originates onsite and/or on neighboring parcel. Location is outside WLRD Servic DATE CLOSED: lq % 7/ �/tsBy: �l �V Prior investigation addresses problem: SEE FILE # Other (Specify): King County Department of Natural Resources Water and Land Resources Division ,oval Drainage Services Unit Basin blk Council Dist. 6 initials dcd Name: Al Button Address: 715 south 50" st City renton State wa Zip 98055 Phone: Day 255-6289 Phone: Evening Complaint #97-1384 Received 9-23-97 Assigned Date 9-30-97 Report Date 10-8-97 Thomas Bros. 686b2 STR 31-23-5 Facility # Investigation Date: 10-7-97 Parcel #3123059049 Maintenance Div. Renton Plat Name: I met with the complainant at her home to discuss her concerns about the drainage on a private access drive for 8 homes. The first two properties on the north side of the access drive are located within KC on SE 187' street (private road). South 50`h on the Renton side of the access road also is a private road. Water runs down the asphalt private access drive on the county side down to the renton side of the access road. The water than runs down the driveway to Mrs. Button mobile home. Mrs. Button would like the county to do something about the drainage on the access road. I explained to her that the County doesn't maintain private access roads or the drainage on them. She was also concerned about a concrete pipe across the street that was cracked. This pipe is a driveway culvert and the owner punched a hole in the top of the pipe and installed a yard drain. No problem with the concrete pipe. All concerns are considered a private problem. 1 told her I would still screen the complaint and call her if there was any change in the investigation. CITY OF RENTON KING COUNTY Icing County Department of Natural Resources Water and Land Resources Division 700 Fifth Ave, Suite 2200 Seattle, WA 98104-5022 L� Aa DETACH HERE ^----_ --- Complaint # ,212-/M� Please take a moment to till out this survey. Your input will help us improve our customer service. 1. Were you able to conveniently reach the right person at Water and Land Resources to assist you? 2. Once the complaint was taken, did staff clearly explain how your complaint will be handled and what to expect? 1 _ 3. During our investigation of your complaint, were you satisfied with how well you were kept informed? 4. During our investigation, did we meet our agmementicommitments? 5. Was the staff professional and courteous? 6. Overall, how do you feel about our performance investigating your complaint? Name: (optional) Phone: ❑ YES ❑ NO ❑ YES ❑ NO ❑ YES ❑ NO ❑ YES ❑ NO ❑ YES ❑ NO y COMPLN TY PROBLEM TYPE OF NEW NUMBER PE ADDRESS PROBLEM COMMENTS TH BR 75-0066 C 19225 SPRINGBROOK RD S POND MUDDY CONDITION 686B2 82-0183 C 10034 SE 190TH ST FLDG 686B2 66-03A7 C 18600 TALBOT RD SE FLDG IN RENTON 686B2 88-0130 X 19219 102ND AVE SE DRNG ® PARKRIDGE EAST/OVERFLOW AND 686B2 EROSION 90-1610 C 730 S 55TH ST FLDG EROSION, SLIDE/HOUSE CONST 686B2 J 1) N 4 � 49 ! 416 �..V 10 410 I , ` e. x • lob a ' a• . r � IL Vic. � ell •{ h j `. 0 L� 1 i + fo I I ,a w � � c I a o m • o w � x ro r O � 32,V rl 1 NOF-00-02E �- E L.N,�iJ F.aWS/aJ.ta�n AW.. } ... '�;�"' • ��r/ gy=m � ' L `+\ ' n T. w+r = .44 •+r sy 4Sur1 s� �' �Yj •{i � � ,� I r, � � ' � yr -• � ti, � +,'.h ' � � ` w ; /{ W fv r. A 1 o czla f .'�^ s��o i i •_� m I r '. ten`' ti:J'r� Sj•� �i W�cl1: e 7 "a J*v�i nCO. ymdE y a Lc r 11 LO 687 —1 N ..•s z; 11 Olhi f 35 AYorts[ � � m i N (+7 ~' nl rar 35 J � �`ar I� �I i F AY 01%51 q A k H1[1! h �9f � �AY �Ma-4 AY Kati w 35AY Ha►1 Ki W1 'A r` C' J4nl - i ld M1►►i n til 3S AY H15►j yS FSI �; ]4154 a�rn 35 v t hN0111�,r Wlft[ r Ar ~ an a SE AV Mlfti AY�fl�if[' .. A4 S w IAIBfi !s¢ ; ate, C; f pas AY am .V, JAV 0 N„ ��� y f 0 4 _ 3s Ar H10►i Q� = Av N € € Y AI•, w•.SEA SM 7Sy M19C! ❑ACL ,ri Y NeYI t4 ' I is w awl pY _ a Y aaLr ri = +h w n �, 7� y L r- Tl' �s d jt3i A SEI x arc, earl --uur , n E Y A. Jf. ►Irrzr` ! P � a 3s AY IT. - .. �� ' 3S � IT] AY mea UHIEI oar PC 5z `•Sr � >t �19jr E� � ` ,�)S 4 ..:il^r y. �_:! ��p yj •r y � .ti, til a G r" 'Y $ Z �� x M � R Hr�iM �t r _ X " %e' y y �� _ cK el X _ - .ar�� ~ r .� rns .. a �, KIWI 35 Id a "s Ae Y Nl1SiL N141 pppa���j ,tG _ LL • +� i fifri 3S AYar Xlirt cl v M� _. .� .. Ar N1►27-' ' $ W N xf35 Ow[ 3S Ar Hl► N35Zl���N i4 it C ars p ! W'Ji �'j „ AY 3SF eAY sit i p L HL►ZI AY NI521 4�: ; y .. 35 Id 1S14 Y tiLrl x� - .r ~' t!" S[ is w AYHIQSI� __ ____ Ytslil 7S '.' AY [ )S 35 AY H18[7 � 61II �� :, xNJ IL r AYE H3021 cr Ai � � •:cte � �' -.w r _-3s AV T811 �I � � N OOOPttxX 75 Afsrpl !< � KIYI[ �. r � �; � S w'3 Y y, •.'iia ,r �` H16Z7 1v�{ K L 35 M ILL611� .li '_y u U ti IS7TH Y W 'r� -. r4BlI ,.,�"'. .-�-.. = Y N -- r- �I h1[ , FLL9r[� X d ' :7 s `-' --- o r 3SAv ►[, 33AYx ►7T I rN[, x ' _ �i.y �L F1192I '.v. ,lit mSi2 - ,`R ri = ,N " h �� - r__•S^w' y i., ..x _ . HMsrr ��LL T, &L I j i,•',,.A �= I ylill Alin S'a• 4 � n �.l��} Tar I 4�•I ��ry, * i rM y r T, -4 '1� �i Ij ~ it x 1 x81V_-II �io';tvo[ -L Z3 3S 4Y lUOI[ L�"�` - '^ " � N3S kt8 Ad i v N a' 3s a cis 1, HJ LT 3t NJS01 := ° 354^ 'AY C,� yr u wfor c J R�. ; A N(fel -___! '� y. 35 n Nl j _ �'� _ 6 L� - - — - - —�— - is w V. N/bl 35 ► 17fk I 71 S 's 3S AY N1301 + E Y Nero[ 37 (< • rw ,'�� ,. M pf Rti°, a r r _r 1S tia ruq[ cY i ra H3.f0[ is `1 M7 � a^ y }^ 0180[ N' � � 3s v , NMI r 3l M wso[ 'n 0� 13s - AY - ^_ prolx , 35 [Arw, ,� , d AY H1ti0T 1 h 1 OROlr' 1d OIyQI € jf A pL01 Sf t x� �R iA r` g w rssM �� 1� r ~ ' r ?' 3S M !47 yHLMI 45 L r !r ris AY H100I 4^ AY %$w AY Ni" ` 1^ ro `rs r- N�AIL ♦ a M e. S 141116\� 141116 NL% G r S V M ]@ yP@ S _ J •_ wcc s AN as / F—� Hl9a Nuc N l2 y € W ,v .y .n cratlsc S 7A_ `S AY Hle6 to AY 111106 S M HMA � b s S Ar o[td 'yLQ AY 6:� 5_ �y ___r___ •moi 9 't7 a fs eTi A Mift t M AY___ ¢ 1Nun F -!71 � Ar Km s s AY / �__ HIS r lA HJSY S S_—AYh - ~ _ W 3M „I H! SAY -+ € S AY mm wso 'N N tLue 5 to S AY dH lYh 3 - - � lYtliM3� A csx� m An /A /A JM DRAINAGE INVESTIGATION REPORT Page 1: 1NvEsnGAnoN REQUEST PROBLEM: P -V PA' ' Type -P'P6"41LE No. q 7 -- /5 Received from: �— (Day) L (Eve) NAME: PHONEo 9/ ADDRESS: !' f 2ZCity State Zip -W -an J� Location of problem, if different: oars (2u -e sZE 5G sIE:, ldoe�o ZZ 677` Reported Problem. CALL FIRST 0 (Would LUce To Be Present) CP C Dom? r�9'�') Q�1� _7` Z;b az;1,2/ tat name: 44) Lot No: M c Block No: Other agencies involved: No field investigation required - (initials) To BE COMPLETED BY COMPLAINT PROGRAM �1/l! 7 i/a S T R Parcel No. -)E t 14 a - C(g 54 Kroll [ Th.Bros: New -J& G' G Old 4('� Basin 3lIe- Council District. Charge No. RESPONSE. Citizen notified on / Z- '% I - `i 7 by: '4 phone letter in person Cpr [ p A�5' Re fo"gre— � cµ. std � /�r?'-' ".7 jAer , ��' �LY4 � /�� � o v �-`� �-�.,4� .t.��.-��v.�-cam /?�s� �t✓� y l3 � t, rT'� � .57.t� v� " L,Avo,V-7- IV K. rzs� rte- • �/� o v , b 7J �S r?. �s '.v c r DI5Posinom Turned to on / 1 by OR: No further action recommended because: Lead agency has been notified: Problem has been corrected. No problem has been identified. Prior investigation addresses problem: SEE FYLE N Private problem - NDAP will not consider because: Water originates onsite and/or on neighboring parcel. Location is outside WLRD Servir7 Other (Specify): DATE CLOSED: �1�41 By: Ming County Department of Natural Resources Water and Land Resources Division 700 Fifth Ave, Suite 2200 Seattle. WA 98104-5022 ----------------_. - DFTACHHERE r Complaint #97 —/5� ! Please take a moment to fill out this survey. Yourinput will help us improve our customer service. I. Were you able to conveniently reach the right person at Water and Land Resources to assist ❑ YES ❑ NO you? 2. Once the complaint was taken, did staff clearly explain how your complaint will be handled ❑ YES ❑ NO and what to expect? 3. During our investigation of your complaint, were you satisfied with how well you were kept ❑ YES ❑ NO informed? 4. During our investigation, did we meet our agreement/commitments? ❑ YES ❑ NO 5. Was the staff professional and courteous? ❑ YES ❑ NO 6. Overall, how do you feel about our performance investigating your complaint? /Name: (optional) Phone: Complaint Number: 97 - 1581 e Received: �" �� 7 e of King County Water and Land Resources Division's services is to provide a contact for drainage and water quality concerns and problems. Citizens assist us by informing us when they notice these types of problems. The Local Drainage Services Unit will investigate and determine responsibility for the problem, refer complaints to the appropriate group or agency, and direct customers to other sources of assistance for problems outside the agency's scope of responsibility. To ensure proper referral, we conducted an initial review/field investigation of your complaint on2 1 7 97 ❑ Requires further review by an engineer to determine proper referral or resolution/closure. If you have not been contacted within , feel free to call at , our complain investigation line, 296-1900 or toll free at 8001 325-6165 (King County Information will transfer you). `Your complaint was closed (in person or on the phone) on IK;L .? ? by ;Z Was referred to: ❑ King County Department of Development and Environmental Services ❑ Other ❑ King County Roads Referral Contact: I- fo ,4 � (z),,*s) at`L96 - 7 �'7/ We appreciate your patience.... During severe rainstorms, we receive an unusually high volume of drainage complaints. Although weF 0 assign additional staff to handle these calls, you may experience a delay in response to your complaint. _ _ _ _ _ ^ . KEEP TMfS CARD FOR YOUR RECORDS _ .__. . ___ NO POSTAGE NECESSARY IF MAILED IN THE UNITED STATES BUSINESS REPLY MAIL FIRST CLASS MAIL PERMIT NO.1179 SEATTLE, WA POSTAGE WILL BE PAID BY THE ADDRESSEE KING COUNTY DEPT OF NATURAL RESOURCES WATER &z LAND RESOURCES DIVISION 700 FIFTH AVE, SUITE 2200 SEATTLE, WA 98104-9898 ATTN.- LARRY GETTLE, SENIOR ENGINEER IIIII,IIIII11IIIIIaaIaIIIIIIIIIIII10111U1fIIIIIIIII COMPLN TY PROBLEM TYPE OF NEW NUMBER PE ADDRESS PROBLEM COMMENTS TH BR 93-0084 C 102 AV @ 187 ST INQ WINDSOR HGHTS DEVELOPMENT 686C2 93-0965 C 18811 104TH PL SE DRNG COUGAR MEADOWS 686C2 94-0133 C 19223 98TH PL S EROSION DETERIORATING PVT ROAD 686C2 94-0529 WQC 4300 TALBOT RD S WASHING INFO TO DENTAL OFFICE 686C1 94-0955 C 10320 SE 186TH ST DRNG GROUND WATER IMPACT TO 686C2 CRAWLSPACE 94-0995 C 18616 102ND AVE SE FLOODING OBSTRUCTED FLOW BY FREDRICK'S 686C1 PLACE ?? 95-0550 WQC SE 104TH & 192ND A SE HERBICID NO EVIDENCE OF HERBACIDE 686C2 APPLICATION 95-0770 C 18862 103RD CT SE DRAINAGE ALLEDGED DRAINAGE FROM PLAT 686C2 IMPACT PROP 95-0770 R 18862 103RD CT SE DRAINAGE ALLEGED DRAINAGE FROM PLAT 686C2 IMPACT PROP 96-0016 C 10339 SE 187TH PL C/B PVT DRNG SYS CONCERNS ELEV OF 686C2 CB 96-0104 C 18616 102ND AVE SE RUN OFF PRIVATE PROPERTY IMPACTS FROM 686C1 ADJ DEV 96-0104 R 18616 102ND AVE SE RUN OFF PRIVATE PROPERTY IMPACTS FROM 686C1 ADJ DEV 96-0146 FCR 18808 102ND AVE SE POND SHEET FLOW SPREADER IMPACT 686C2 NEIGHBORHOOD 96-0146 R 18808 102ND AVE SE POND SHEET FLOW SPREADER IMPACT 686C2 NEIGHBORHOOD 96-0701 C 10320 SE 194TH ST DRNG SHEET FLOW GRND WATER IMPACT 68602 PVT PROP 96-0817 FCR 10335 SE 187TH PL RET WALL VANDALISM OF BLOCK RETAINING 686C2 WALL 96-1259 R 18862 103RD CT. SE EASEMENT D/S NEIGHBOR WILL MAINTAIN 686C2 96-1332 FCR 18851 103RD CT. SE R/D POND MAINTENANCE ACTIVITY R/D POND 68602 97-0600 C 19121 104TH PL SE DRAINAGE OBSTRUCTED DRAINAGE PVT PROP 686C2 IMP 97-0758 C 19215 98 TH AVE S, #E DRAINAGE CONCERN RE POND SIDE SLOPES 686C2 MEETS STAND 97-1107 WQC 19223 98 TH PL S IRONOXID SHEET FLOW IRON OXIDE 686C2 DISCHARGE OVER SW 97-1213 C 18862 103RD CT SE PIPE PVT PIPE INSTALL IN EASEMENT 68602 PVT REPAIR 97-1239 WQC 18600 102ND AVE NE DUMPING APPEARS TO BE AC'T'IVE CLEARING 686C1 PROD I -# N lip ' �.t .�' .'•� ,r �„ R � � �� 1SR � � �� ��\ '\f„ � I ' � 117 r.' n { ( n ,.' .,. � �l (r I f .. v , � i l•.7 IAT /L,7 / J (r♦ — _ 71 f^- ' 134• "� - .� Y� . t ` � � � ^. IrY r� .... 1\ • a Z, 1 ► p •� AAk q y Jar ,• (r {� V � � �� }r �_� _-•`M1� '`JyJ � �-ti�4 �tb'1 y`! ,«: l3 ta: � �V.s9� � L1 t; a art �� ``�. •'air �,'• �,., o -t VL Yl w � ff rir •+prW :r} i Q�,y '"y v f lrr .r' v t: C� � .Y1 � � a 9• T�ra `-y V Y� � y�� �r'y'l a� Mrs + -1 rt tL! 4 �1 •1 •J. ti J �ul tiC' •� \ is �, �.--+i ■ Ll u a [n fel coAL �? It Ila dr, �17� IL n nr *�,, r �� x r Y { o1_n- - �!� w-` , l=r [C\S i'•t Sit' -- s•�~J. CoOrd 1.4 Ulm f1+�� Lo s i., w 4t' t, Z[ • • Otrd 7 •� `.� —j_ ��'� '...�` -sir �P � •(N � �%`� CJt.L` � a� � / Sir +4�tpl� �': n l4.,Lv1 rQ -cSti 04TH PL. S F -�j a IS V (1 i 1, -+�J �lrr •1° t` Y,,y L r : `:Y1r! ' 4'r t�• stir .. a .• fir•,. �,= l r ff •� •�. •'1 \ h 4_ •.�•, i - I\'"' •�. It ar S •� w .1M -n' �t'► \� }G r " „ti. ` 1 wj 41) 41� i;,'1 1�j� a'k.t4 4i W1 11y � ;j� �C7.1 A i7t 161 E IJY 33S m y E c1a:7 TcLP2 y T N 4 4 CENTRAL E VAI LE 39 Rp ; o� E16TH AY S Ei6TH C .F�i'r- v+ 5 06TH PL T•,7 �' TIE'4 AV 5TH __AY_ S !'" I , I �q - _ R4E I R5E- _ B9r11 Ay S9M AV S ~}.�' s ii I F 119ni ---Ay sBeTMR ----5 - i 4�� SY LIND „ s Ai Y w Y RPYT 9M0 AY ca �~ S g BiTX Ar 5 94TH AV yy 94TH R S w +a A, Nw. •• 94 AV S^� N�w96TH I ,bTY n,x7CT ti* 2f2T 9riH .r vu 4]P➢ A111 AY $� �� `3yyJris p "!}•b W f.. S +m y.. WY i KTM u sa g N lit l._ Iy 1 B61H r . TALB(]TRD y 5 %TH R 98TH Ar S 7BrH s n A 99TH V A Li; ry �A r E re' ,. tiY S 100TH `a AY L Laori `" 7 rz AY r y 8 )a 1n LI I� ' r N I PL 4 �r 1 � � 1 IIY Ar Y .� >w .r 14)3181 YSE�� 110 - 34192x0 104TH ' n AV ISE 57 x �- i� n 1611m 1p7Pn PL SE 1 L 3E 8M. ip2x0 1p7Hn Ar 5E )o5TM AV SE "� Inm ^'M SE i ., k d w PL E . ��>. m K 104TH 1I _ r� '' 2 ���-~,�1, h u - Ertl v %I, 1p41H PL ie ry r z :an lY n1Y IOt+N rL a' �, AY SE 1114 J i x140 is y�I' PL PL SC 1041x Ar SE I 'w IKh Ip�l-� N .. µ34n - — - - - —Ar j� -,. 2 °s ATH "-' i -- - T.TI n r \: f u �' l' ' �^� .` Ar u 4 1067HIo '� )116 Tx PL l� u ,�{r t�. SE � �' � Ht PL SE F �! C ''- Y SC r^+ lo[rx m 1_ lolTx 'I _n r <' 5!- */YS`A IOSTN Yw_ � � I Tx Pt SkW '4'Na." . ,r f-, x' 3 I: 'T I ` -� �1n r 116TH PL SC'r'ni nJ��•.Yp.�; •. Y? S ry��iYx `i ; l Ip1H y��^ I� 1 o I AV ~SE 87N AV =� ' ' ,SEI SE 111'M;AY ii PLxJlr, t 4 J �._)_ 1�j11Y to {� :tnr u sA '"i'E . °I i'^^ry _ I)uy '"�\"+Ji l r^�nsi hL -yA'10LI ! 1L6TN ! n� .� 'c �� Ar l� SEI : - AY 5E 7 ��Ln:m 118 fix AY SF ]]SHAY SE'_ ' .:rl '116TH li AY -r ^ :° IL Y ,SI131 z0, .?-h S .1120Ti1 �Av SE =Lz ca � 1i: nTTfj„ '= .F A1' S[ AV SE __-'�---_, •N•, 1-"s 118TH Av SE P Y ., l iii C7R P _ trl{` K'.� n• .�,c lzlrloSE ��2Itlsra I__ Nl—� 20TH-L.-AY�7:i� I~ ! SE - 21 ST PL��24 \:1 �.�.•s .'q `ls~A�. Y 7P�' Ai 1,y� Q12t5 ;etla�-t 'S "f112 i r I[Lr/��jppr:li!i ur 1H .Y x...'+ 1Ha` !y�i$r nL24TH AY ko AY NSE 1 125THL4TH 1 �a in 11; k '6%�}��L, K • Yn .5-L }�:\%1 ��':I ..I� f s8=t r�s'I 1, l,rS �a _•lr. ry :•0 551] �_' el:7b` awn Iiy t Iz7rHIn « �I AV sE'R a ,P Ixi9i1 - = : � E ...� ,7H V; �rk Y""" N -' AY SE 12ocs, �N A IS ly ,4)Y 'e 2 TN AY SEI= yvl A W :K' K k > s fix„ L J y2arH ttu 126 - $ ILi I�r Y,Ii9 PL a - k ,� •, �' 'R 8 ¢p�1a i M,y3ti PL SI �/ti f %M�jl II N 5 ,y �� r �y ,:rs>• 3 v r• -1.S 4L ` M aI` 1 ` ld ��wzH m 2Wp 132Nd IIBW AY `� ��` r• / R s SE i4 1 2H0 i4' Ai ! '•'F "f�f -i_ 1qr - b rr' 9 Y AY SE y1 E' AY y� ,73+0 a'F r 115 SE I^ M e•9- M SDIX 5.,, 6.,' N 1M w 1]51,1 .rY r B '� '} I E)3o h I�eM t.r Ar i ��.-_..-� 1�.._.: y 41 rs 5 1> p 175 F f I ^ r } I7 .....-._ ..-:-_.-__...... 13 TH !7- Tx Ar f 9 H y- 16isT Ar kE SF y0 202W SE N �, AY rk a i` cu V u � h 14 I�pBpo AY .1'v �; y S y - !8p { 14 AY SE Cb *3t r1r w AY v v n R W AY `^5 .2 A 34 �r T6[ 144TH AY I _`_ 1 1laTx 344THAl w 1a3R11 ,� =rslaq Iai,lO R 1n Y l f� S Is' y j� sE y a .r s[ jZ-1 a I It�'w 1i `5t I aS1H AY SE 144TH I pv r _ I-- w 148TH 1a 7T1E I.rn s: Ar SE 'r' AY ]47714 AY a >E>G x I , h I '- SAmI Ar i2 f'} ,-.. y x I45EN n AY"SE T I AV - lb l �+ rBlx 22/C01- 2600 SE 148TH �%: AY i E 4 Yl r. + "AM L H y 1rry 9I 1^ 1 + yY 1a46p 24771f AV" IAM d •S x ]5 Jcc>l£ii i �I 1Rl 2Nd AY SE A� n r � C f' liiRa R 1530 Ar SE { 1 ; ! , a 4r 7c c ic B E IJY 33S m y E A b 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN 4.1 Existing Site Hydrology The site is located on the west side of 102nd Ave SE, near the 102nd Ave SE & SE 186th Street intersection, in a portion of Section 32, Township 23 North, Range 05 East, W.M., in the City of Renton. The project site is 2.45 acres in size (or 106,680 square feet). The property consists of one tax parcel (Tax Lot No. 3223059097) and there is one single- family home located on site (east side of property) as well as several associated outbuildings, utilities, and private gravel access drive. A majority of the property is a forested area (covered with mixed deciduous/coniferous trees; please reference the Tree Protection Plan prepared by Washington Forestry Consultants, Inc.) and a small wetland located in the northwest corner of the property (Category II Wetland; please reference the Critical Area Study prepared by Wetland Resources, Inc.)_ The site generally slopes from the east to west (approximately 35 feet in elevation change), with a slope averaging from 1% to 2%_ However, in a small area in the northwest corner of the site (near the on-site wetland), the topography increases between 30% and 35%. Per the project surveyor, there are no slopes on site that exceed 40% (as defined in RMC 4-11-190, Slope, Protected and Slope Sensitive). All significant trees on the site have been surveyed (6 -inch diameter at breast height [DBH] or greater) and are shown and identified on the Tree Retention Plan prepared by Barghausen Consulting Engineers, Inc. The understory cover is mixed with Salmonberry, Vine Maple, Western Hazelnut, Sword fern, Salal, Oregon grape, Pacific Blackberry, and portions of the property have ornamental landscaping and grass areas (around and near the existing residence). The on-site soils consist of approximately 4 to 18 inches of topsoil overlying native soils consisting primarily of medium dense to dense silty sand and sandy silt glacial till deposits which are one of the more common soil types in and around the City of Renton. Please see the Geotechnical Report prepared by Earth Solutions NW dated December 15, 2014. As discussed earlier, a small wetland is located in the northwest corner of the property and is classified as a Class 11 Wetland requiring a 50 -foot buffer. The proposed project is utilizing buffer averaging to allow for the construction and future extension of the on-site public roadway (proposed Road A). Please reference the Critical Area Study prepared by Wetland Resources, Inc. dated December January 5, 2015. Access to the site is from 102nd Avenue S.E. (residential access street). A public road will be constructed to provide access to the 8 lots, and will be extended as far north as possible so. that the neighboring property to be developed by Harbour Homes (Vuecrest Estates; City File No. LUA13-000642) can extend the roadway for secondary access. The project site is surrounded by existing single-family subdivisions with similar densities; however, along the south property line there are larger single-family lots (due to topography) that range from 1 to 2 acres in size. Please reference the Boundary and Topographic Survey in Section 1.8 for further detail 17254.001-TIR.doc 4.2 Developed Site Hydrology The Vuecrest II project is a proposed short plat, consisting of 8 lots. As designed, there are approximately 690 lineal feet of proposed on-site public right-of-way (half street), which will have 32 to 39.5 feet of public right-of-way with 20 to 26 feet of paving, curb, gutter, planter (8 feet wide in portions), and sidewalk (5 feet wide). The project development will utilize and extend existing public utilities through the project site (water and sewer provided by Soos Creek Water and Sewer District) along with storm drainage and dry utilities (power, telephone, natural gas, and cable) serving all lots. Sewer will be extended from the Plat of Vuecrest Estates (City File No. LUA13-000642) to the west property line of the Vuecrest II Short Plat. Please reference the Conceptual Utility Plan prepared by Barghausen Consulting Engineers, Inc. for more detailed information. In order to construct the project as generally depicted on the preliminary grading plan, approximately 2.05 acres will be cleared. Approximately 7,600 cubic yards of structural soil will be cut for grading the roads and lots. A majority of this cut material will be used on site to construct the project to the final design grades. Any excess structural material will be exported from the site during construction along with any excess topsoil_ These figures are approximate and will be determined at final engineering design. Stormwater runoff from the Vuecrest II project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). The project is located in a Conservation Flow Control area (Level 2 Flow Control); however, as noted in the TIR prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, due to a connection through the downstream system the project will adhere to Level 3 Flow Control requirements. A Technical Information Report (TIR) has been prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, dated July 15, 2014, which will be updated during final engineering design to include developed areas from the Vuecrest II project. For further detail please reference the Preliminary Grading & Drainage Plan in Section 1.3. 4.3 Performance Standards Stormwater runoff from the Vuecrest II project will be conveyed offsite to the drainage facility for Vuecrest Estates, which will be sized to include the future developed site area from the Vuecrest II project. The off-site drainage facility will be required to provide Basic Water Quality Treatment and Level 3 Flow Control for the developed areas from this project, following the 2009 King County Surface Water Design Manual (KCSWDM). The project is located in a Conservation Flow Control area (Level 2 Flow Control); however, as noted in the TIR prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, due to a connection through the downstream system the project will adhere to Level 3 Flow Control requirements. A Technical Information Report (TIR) has been prepared by DR Strong Consulting Engineers, Inc. for the Vuecrest Estates project, dated July 15, 2014, which will be `rk.&VIu111e11 arra updated during final engineering design to include developed areas from the Vuecrest II project. 4.4 Flow Control System Flow Control System details will be submitted during final engineering_ 4.5 Water Quality System Water Quality System details will be submitted during final engineering. irX.E.rIIIIaIIOrt r. 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN Conveyance system analysis and backwater calculations will be provided in final engineering. 17254.001-TIR.dac 6.0 SPECIAL REPORTS AND STUDIES The following special reports have been prepared and have been submitted under separate cover. • Critical Area Study prepared by Wetland Resources, Inc. dated December January 5, 2015. • Geotechnical Report prepared by Earth Solutions NW dated December 15, 2014. The following reports are included in this section: 6.1 Black River Basin Reconnaissance Report No. 14, prepared June 1987 17254.001-TIR.doc 6.1 Black River Basin Reconnaissance Report No. 14, prepared June 1987 RECONNAISSANCE REPORT NO. 14 BLACK ]LIVER BASIN JUNE 1937 Natural Resources and Parks Division and Surface Water Management Division King County, Washington P.M.TOC/mlin King County accutiive Tim Hill King County Council Audrey Ginger, District 1 Cynthia Sullivan, District ? Bill Reams, District 3 Lois North, District 4 Ron Sims, District S Bruce Laing, District 6 Paul Barden, District 7 Bob Grieve, District 8 Gary Grant, District 9 Department of Public Works Don LaBelle, Director Surface Water Management Division Joseph J. Simmler, Division Manager Jim Kramer, Assistant Division Manager Dave Clark, Manager, River & Water Resource Section i.arry Gibbons, Wnager, Project Management and Design Section Contributing Staff Doug Chin, Sr. Engineer Randall Parsons Sr. Engineer Andy Levesque, Sr. En;ineer Bruce Barker, Engineer Arny Stonkus, Engineer Ray Steiger. Engineer Pete Ringen, Engineer Consulting Staff Don Spencer, Associate Geologist, Earth Consultants, Inc. John Bethel, Soil Scientist, Earth Consultants, Inc. P:CR Parks, Planning and Resources Joe Nagel, Director Natural Resources and Parks Division Russ Cahill, Division Manager Bill Jolly, Acting Division Manager Derek Paan, Chief, Resources Planning Section Bill Eckel. Manager, Basin Planning Program Contributing Staff Ray Heller, Project Manager & Team Leader Matthew Clark, Project Manager Robert R. FEierstenberg, Biologist & Team Leader Matthew J. Btnengo, Geologist Lee Benda, Geologist Derek Booth, Geologist Dyanne Sheldon, Wetlands Biologist Cindy Baker, Earth Scientist Di Johnson, Planning Support 'Technician Robert Radek. Planning Support Technician Randal Bays, Planning Support Technician Fred Bentler, Planning Support Technician Mark Hudson, Planning Support Technician Sharon Clausen, Planning Support Technician David Truax, Planning Support Technician Brian Vanderburg, Planning Support Technician Carolyn M. Byerly, Technical Writer Susanna HorniCr g. Technic�ll Writer Virginia Newman, Graphic Artist Marcia McNulty, Typesetter Mildred Miller, Typesetter Jaki Reed, Typesetter Lela Lira, Office Technician Marty Cox, Office Technician TABLE OF CONTENTS I, SUMMARY II. INTRODUCTION III. FINDINGS IN BLACK RIVER BASIN A. Overview B. Effects of Urbanization C. Specific Problems IV. RECOMMENDATIONS A. Expand existing and/or construct additional R/D facilities B. Preserve wetlands on plateau to provide natural storage C. Protect steep valley walls from erosion and landslides D. Reduce sedimentation in streams alone valley floor E. Enforce prohibitions against dumping domestic trash F. Increase the overall effectiveness of surface water management V. MAI' APPENDICES APPENDIX A: Estimated Costs APPENDIX B. Capital Improvement Projects Rating List APPENDIX C. Detailed Findings and Recommendations P:BR.TOC/mlm I I 2 2 4 5 7 7 7 7 7 7 8 9 A. -I B-1 C -I I. SUMMARY Black River Basin, located in south King County, is named for a river that ceased to exist in 1917, after major alterations to river systems were made to build the Lake Washington ship canal. The reconnaissance was conducted along the streams and tributaries still remaining in this basin. Development in the basin in and around the cities of '(Cent, Renton, and Tukwila has produced extensive areas of impervious surface, which are expected to double by the time the basin reaches its development capacity. Storm runoff from impervious surfaces is drained through pipes and discharges in some cases directly into the stream system. Field investigation of problems in the Black River Basin revealed that volumes and rates of stormwater flows have contributed to serious acceleration of erosion of streambanks and lower slopes and have produced dowurutting and landslides in some places. Sedimentation resulting from these processes has, in turn, clogged existing conveyance systems, rendering many of them ineffective, and destroycd fish habitat for spawning, rearing, and migrating. In addition, the general inefficiency of the basin drainage system has increased the potential for flooding. Another problem cited was visibly poor water quality resulting from large amounts of domestic trash placed in streambeds and from commercial industrial runoff, particularly near the Longacres Racetrack in Renton. Recommendations for action in the Black River Basin include: 1) expanding RID facilities and preserving wetlands to assure adequate stormwater storage, 2) taking measures to protect steep valley walls from, erosion and landslid(s, 3) reducing sedimentation on the valley floor with sediment traps. 4) increasing enforcement of regulations against the dumping of trash into streams, and 5) increasing the overall effectiveness of surface water management in the basin through doing more maintenance of facilities, continuing intergovernmental agreements, lowering volumes and rates of release for stormwater, and other measures. II. INIRODUCITON, I-Estory and Goals of the Program In 19:15 the King County Council approved funding for the Planning Division (now called the Natural Resources and Parks DNESion), ill coordination with the Surface Water Management Division, to conduct a reconnaissance of 29 major drainage basins located in King County. The effort began with an initial investigation of three basins -- Evans, Soos, and Hvtebos Creeks -- in order to determine existing and potential surface water problems and to recom- mend action to mitigate and prevent these problems. These initial investigations used available data and new field observations to examine geology. hydrology and habitat conditions in each basin. Findings from these three basins led the King County Council to adopt Resolution 6013 in April 1986, calling for reconnaissance to be completed on the retraining 26 basins. The Basin Reconnaissance Program, which was subsequently established, is now an important ele- ment of surface water management. The goals of the program are to provide useful data with regard to IJ critical prob[ettts heeding immediate solutions, 2) basin characteristics for use in the preparation of detailed basin Enanagement plans, and 3) capital costs associated with the early resolution of drainage problems. The reconnaiss<-ince reports are intended to provide an evaluation of present drainage con- ditions in the County in order to transmit information to policymakers to aid them in deve- loping more detailed regulatory measures and specific capital improvement plans. They are not intended to ascribe in any conclusive manner the causes of drainage or erosion problems; instead, they are to be used as initial surveys front which choices for subsequent detailed engineering and other professional environmental analyses may be made. Due to the limited amount of time available for the field work in each basin, tate reports must be viewed as P:BR/jr i Black River Basin (continued) descriptive environmental narratives rather than as final engineering conclusions, Recon3mcndations contained in each report provide a description of potential mitigative measures for each particular basin; these measures might provide maximum environmental protection through capital project construction or development approval conditions. The appropriate extent of such measures will be decided on a case-by-case basis by County offi- cials responsible for reviewing applications for permit approvals and for choosing among com- peting projects for public construction. Nothing in the reports is intended to substitute for a more thorough environmental and engineering analysis possible on a site-specific basis for any proposal. M. FTNDINGS IN BLACK RIVER BASIN The field reconnaissance in Black River Basin was conducted in February 1937 by Ray Heller, resource planner; Ray Steiger and Doug Chin, engineers; and Matthew ). Brunengo, geologist. Their findings and recommendations are presented here. A. Overview of Black River Basin Gwg-dphic and land use features. Black River Basin is generally bounded on the north by the cities of Renton and Tukwila and on tate south by the city of Kent. The western and eastern boundaries are formed by the Green River and 116th Avenue Sty, respectively, in this southern King County basin. The Black River, which gives its name to this basin, actually ceased to exist in 1017, when the Uike Washington ship canal was built and the level of Lake Washington was lowered, cutting off flow to the Black River. Tile 28_square-mile basin investigated by this field team includes what remains of the network of tributaries that formerly connected with the Black River, The Black River Basin is split nearly equally into an eastern upland plateau and a western floodplain in the Lower Green River Valley along State Road (SR) 167. The floodplain is almost wholly contained within the cities of Tukwila. Renton, and Kent, where extensive development in the last two decades has changed the landscape from a rural farming area to a commercial and industrial one. While open space and farming still exist here, the area will be infilled, primarily by a combination of commercial, industrial, and some multi -family complexes, by the year 2000. The King County Comprehensive flan shows that the upland area will be developed at urban densities. This transition is already in progress, with commercial developments emerging along the Kent-Kangley Highway (SR 516), the Benson Highway (SR 5I5). and the Carr Road -176th Street Sir-Petrovitsky Road corridor_ Multi -family land use occurs in tite uplands also and surrounds commercial developments. New single-family units are beijtg built throughout most of the eastern upland portion of the basin. Thee amount of impervious surface is expected to nearly double between 1985 and tate time the basin is fully developed. This will require strict controls on surface water discharge to assure prevention of further degradation of the stream system, which has already begun to exhibit adverse environmental impacts resulting from urbanization. Other factors of concern in this basin are those sensitive areas occupied by wetlands, streams, floodplains. coal -mine zones, and landslide zones. Mostly located in tate eastern portion of the basin. these areas have already been damaged by the effects of develop- P:B'Rlir Black River Basin (continued) mens, Details of the damage, along with suggestions for mitigation, are contained in later section of this report. Dominant geologic and: geomorphic features, Black River Basin consists of the part of the Duwamish Valley east of the Green River and the western edge of the Covington drift plain, a plateau underlain by glacial deposits. Small creeks, which flow across its rolling surface, have eroded deep, narrow ravines up to 1.5 miles into the plateau. Downeutting is migrating headward in the upper reaches, and erosion of banks and lower slopes causes landsliding in the canvon walls, most of which are naturally unstable. Both of these processes are accelerated by increased flows attributable: to urbanization. Sediment is deposited where the streams flow onto the valley floor. The surface of the Covington drift plain is dominantly basal till, mantled in places will, recessional outwaslt or deposits of post -glacial lakes. Near the edge of the plateau are several lenses of sediment deposited adjacent to a glacier lobe in the Duwatnisl3 Vallev, Older sedimcnis are exposed in the ravines and bluffs. In the north, unconsolidated sediments lap up onto the southern limb of the Newcastle anticline: sedimentary and volcanic rocks crop out in the bluffs north of Panther Creek and form the Renton. Talbot, and Earlinbton Hills in the northern end of the valley toward Tukwila_ Coal was mined from this area from 1353 until the 1940s. The Duwarnish Valley is part of a trough carved into the drift plain during the last glaciation; it later became an arm of Puget Sound. A catastrophic mudflow originating on Mount Rainier approximately 5700 years ago dumped massive amounts of debris into the trough. 'This and other events, plus the deposition of alluvial sediment, expelled the salt water. Thlrouglt the nineteenth century, the combined White and Green Rivers n7Candered through the valley, Near Renton, the Cedar River flowed into the Black which drained Lake Washington and flowed into the Duwamish. Beginning in 1906 a series of changes was made to these river systems. The Cedar River was diverted into Lake Washington, and the White River was diverted south to the Puyallup. The Black River itself ceased to exist. Geomorphic processes in the Black River Basin are most active on tite western edge of the plateau. Lakes and wetlands formed here in tite poorly drained swales. Where conditions of drainage and percolation are appropriate, small streams flow between the drumlins, eroding deep ravines into the unconsolidated sediments in the process. Opfer time, the ravines have been widened by mass -wasting of their walls (a process aided Uy groundwater) and erosion by tributary creeks; their upper ends ]lave migrated their upstream into the plateau. Sediment carried by these streams was deposited in the Duwamislt trough; after the trottgli became an alluvial valfev, small fans formed on its edge. IIydrologic and hydraulic feature. 'There: are three distinct geographic features asso- ciated with the hydraulics of Black River Basin: the plateau east of the Lower Green River Valley, the steep (5-35°) erosive hillsides, and tite flat floodplain of the valfev floor. Mill. (jarrison. Springbrook, and Panther Creeks, as well as three small, unnarrted tri- butaries (0023, 0006B, and 00060), all originate from locations oft top of the plateau. Panther Creek originates from Panther Lake and the surrounding wetlands. The P:BR/Jr 3 Black River Basin (continued) retraining tributaries originate primarily from Srirface water stored in natural depressions and wetland areas along the top of the hill. The surface water is collected and routed generally north and west via natural swales, open roadside ditches, culverts, and pipelines within street rights-of-way and, finally, down the steep hillsides to the valley floor. Mill Creek, located at the southernmost end of the Black River Basin. flows north between the Green River and SR 167 and then crosses under the highway at various locations. Mill, Springbrook, and Garrison Creeks continue north along the west side of SR 167 and eventually combine as Springbrook Creek before being pumped into the Green River through King County's Black River pump station. Tributaries 0006B and 00060 flow north independently down the hillside adjacent to Interstate 405 and into Renton, where they enter the city's storm drain system. Habitat characteristics. 'floc use of natural streanis for urban stormwatcr conduits has had a detrimental effect on most stream systems in the Black River Basin. Increased stormwater release rates that are higher than streams can convey without problems have resulted in extensive erosion, sedimentation, and landslides. Water quality problems caused by domestic aarbaAe placed in strvFims. and point discharges of pollutants are additional factors. What is striking about this basin is that these habitat problems exist everywhere. While some problems are worse than others, their impact on the fish habitat of each stream examined was profound. No fish were observed in any streams during (lie investigation. For this reason it is surprising that tine fish counter at the Black River pump plant located on Monster Road (through which all water in the basin is discharged into the Green River recorded 44 fish entering the stream system in 1456. While this figure is higher than that for fish counts in the previous five years, it is significantly lower than historical levels or the potential levels that nnight be achieved if streams were in better condition for spawning. The current habitat conditions offer little hope for the future of these salmon runs. To reach spawning areas fish must first pass through an open flood -control drainage ditch for a nnintnlutn of five miles. This ditch has no vegetation or pool protection for fish to take refuge against predators or water -temperature increases. In addition, water quality is visibly poor. The eggs of fish that do reach spawning territory are likely to be smothered with sediment or washed out during ltcavy rainstorms. If these problems associated with development worsen, streann systems will probably be left biologically sterile. Reversing this pattern of degradation is dependent on revising the policies and priorities in the planning and zoning activities. the develop- ment review processes on the Surface Water Management programs of King Covrav, Renton. Tukwihi. and Kent. B. Effects of Urbanisation in the Basin The existing upper reaches of the Black River Basin were once heavily vegetated, and natural depressions retained much of the surface water. Water was released slowly Illen, and [lie stream systems could convey flows easily. Development has brought about tile, removal of this veoctative cover and filling of the natural depressions. Many streams arc now being piped. Impervious surfaces are increasing and will eventually account for 50 percent of the basin's surface area. In general, surface water is entering natural systems at a faster and higher rate than before development accelerated two decades ago. ]1:BR4ir 4 Black River Basin (continued) Earlier discussions pointed out the serious effects this is producing in the form of ero- sion and sediment transport to lower stream reaches. Additionally, sedimentation decreases the efficiency of the entire basin drainage system by filling culverts and chan- nels. This in turn increases the potential for flooding. The city of Kent removes an estimated 1,100 cubic yards of sediment annually from its sediment facility at Mill Creek Park. 'The Washington State Department of Transportation also employs a regular cleaning schedule to remove gravel and sediment from its culvert under South 212th Street on Tributary 0023. Sediment from Springbrook Creek has been transported downstream from the erosive hillside to a pri- vate trout farm west of Talbot Road and rendered it inoperative. Similar examples occur throughout the basin along the bottom of the steep hillside and east of State Road 167. Erosion is further accelerated by drainage outlets from developments and public areas. Discharge from a pipe into Garrison Creek adjacent to Benson Road freefalls for approximately 10 feet before scouring the ravine it enters. Similar erosion occurs on Tributary 0006B where water is discharged from the Fred Nelson .Junior High School across Benson Road to the top of a severely eroded ravine. An onsite detention facility downstream at the Victoria Hills housing development accumulates large amounts of sediment. Its capacity is decreasing, and the function of tite facility is threatened. The development trends in this basin mean that land for regional R/D facilities will become more difficult to obtain at the same time that erasion and potential for flooding are increasing. Additional problems may arise if existing onsite R/D systems malfunction from improper design or construction or from lack of maintenance. An onsite facility for a privately developed trailer park, located west of the Benson Rodd adjacent to Garrison Creek, exemplifies the potential hazard. Unstable fill was placed on the steep ravine and an R/D pond built on its edge. The fill becomes saturated when the pond is in use, and tension cracks in the fill along the slope indicate potential fallt[!'C. Such an event would add large amounts of sediment to the drainage system. Development may create similar problems elsewhere if the proper design, construetion, inspection, and maintenance of R/D facilities is neglected. C. Specific Problems Identified Black River i3asin exhibits serious problems throughout its system, with exceptions only in the south fork of Springbrook Creek and on Panther Creek in subcatchment 10. The most significant problems noted by the field team during its investigation are listcd below. I. Stream channel erosion accelerated by the routing of runoff from developed areas into streams. Major problems exist in the ravines, where streams are cutting into till at the upper ends of cane_ ons and associated landsliding and surface erosion occur (see section 3 below). Although these processes have been taking place naturally for a long time, increased runoff from developing areas on the plateau is causing acceleration of the erosion. a. The worst cases of erosion observed include those on Mill Creek (0005), P:BR/ir 5 Black River Basin (continued) Garrison Creek (0022) and its tributaries (0023, 0024, and 0025), the north fork of Springbrook Creek (0021), and Panther Creek (0006). b. Prominent examples of gullying at drainage-stmcture outfalls are in Mill Creek (0005), Sprinpbrook Creek (0021), Panther Creek (0006), and below Benson Road on both Garrison Creek (0022) and Talbot Creek (0006B). c. Examples of accelerated downcutting resulting from increased runoff from developing areas are located in Talbot Creek and two small streams (0064A and 00060) in Renton. 2. Iandsliding associated with stream erosion in ravines, as a result of steep slopes and saturated soils. Instability generally takes the form of rotational failures or debris slides triggered by stream undercutting. In many cases, natural instability is exacerbated by filling and/or by construction on canvon wails: for example, a new fill above Garrison Creek at Benson Road is failing, and old fills are being under- cut. All of the ravines should be considered landslide -hazard areas. The same is true of the bluffs at the western edge of the plateau. even though there have not been many problems yet. These are moderate to steep, landslide-stiseeptible slo- pes, especially in the northern (Renton) and southern (Kent) ends of the basin -- the area under the most development pressure. 3. Damage to (or destruction of) habitat due to: a. High flows and high velocities, which remove macroplhytes and benthic orga- nisms, plants, insects, and possibly fish. Visible evidence of high velocities was noted on all the streams in this basin except the south fork of Springbrook Creek. b. Sedimentation from excessive erosion, which is fitting pools, choking spawning gravels, and in some cases filling stream beds to the point of making channels impassible to fish. All of the four big stream systems in Black River Basin exhibit this problem. The Kent parks department annually removes 1.100 cubic yards of material from ,Mill Creek. A large sediillcrlt flow has filled the Sprinpbrook Creek stream channel to a depth of approximalely 5 feet, and Panther Creek just north of Valley General Hospital leas a large alluvial fan_ c. Visibly poor water quality: 1) I_arge amounts of domestic trash have been deposited in these stream cannons. Mill Creek has become a dump for appliances at river mile 9.60, and Garrison Creek appears to be more of a landfill loan a creek at 1.30. Such practices have a detrimental effect on water quality as well as the visual duality of the environment. 2) Commercial and industrial enterprises are producing runoff that causes nhaity streams to be oily, turbid, and sudsy. Springbrook Creek (Trib- 0005 at RM .1.30), flowing tinder the bridge of Southwesi 16th Street just cast of Longacres in Renron, is one of the worst examples noted. The Western Processing facility just upstream has been LdeLltifLed as a source of toxic wastes entering both surface and groundwater systeins, 1':BR/jr 6 Black River Basin (continued) IV. RECOMMENDATIONS FOR ACITON Habitat, erosion, landslidin& and flooding problems in the Black River Basin can be addressed by the measures identified below. Most of tite solutions listed here will mitigate specific problems observed during field investigation or will prevent similar problems in the future. Howevea-, additional recommendations have been included to sugg in this basin. est administrative or regulatory measures that would increase the overall effectiveness of surface water management A. Expand existing and/or construct additional regional RID facilities on the plateau in order to control storm flows that originate there. Site facilities upstream of the four large creek ravines that are experiencing the worst danyage. )Facilities should be regional in scope and should follow the general specifi- cations outlined in Appendix A of this report, These will impede the direct conveyance Of runoff into the steep, naturally erosive ravines, thereby reducing erosion rates that result in sediment transport and slope instability and that damage habitat. B. Preserve wetlands on the plateau to provide natural storage. In addition, reconsider Panther Uke for use as a regional R/D site. Although the lake has been classified as i #1-C wetland, the amount of storage it offers is substantial with a moderate addi- tional (.25 -to .50 -foot) fluctuation in depth. - C. Protect steep valley walls from erosion and landslides caused from direct discharges of stormwater_ I. Tight"c discharges or provide other appropriate nonerosive conveyance over steep hillsides; provide energy dissipation at the outfalls. This has already been done at several points on Mill Creek (Tributary 0005) with good results. 2. Consider rerouting flow in cases where tightlining or other methods are not feasible. For example, runoff from the area southeast of Springbrook Creek might be piped down Southeast 200th Street rather than routed into the north fork (0021) as it is now. 3. Lower the potential for landslides by restricting development in and along the tops of ravines. In particular, strongly discourage filling along the edges; the fill at Benson Road above Garrison Creek (0072) will probably have to be removed. D. Reduce sedimentation in streams along the valley floor in eases where sedimentation is not adequately prevented by R/D and other upstream measures. In extreme cases (probably including Panther Creek (00061?, construct sediment traps (with convenicnt access for removal of accumulated material) at points where streams flow onto the vallev floor, E. Increase enforcement of regulations against the dumping of domestic trash into ravines and stream channels. The Seattle -King County Health Department and the Kin; County office of Building and Land Development should be asked to investi gate this ongoing problem and to take appropriate action when violators are identified. P:BR/ir 7 Black River Basin (conllnued) F Increase the overall effectiveness of surface water management in the Black River Basin: L Continue cooperative intergovernmental arrangements between the cities of Tukwila, Kent, and Renton; the Washington State Department of Transportation; and the King County Surface Water Management Division to identify and propose solutions to habitat and hydraulic problems in the basin. These efforts should include de- velopin; cost-sharing agreements where capital improvements are required. 2. Evaluate and reduce, if appropriate, the volumes and rates of release for stormwater originating from developments. Present release rates and volumes are causing erosion, sedimentation and habitat ,problems. 3. Increase the maintenance and inspection of existing King County and city drainage systems to ensure that they are functioning properly. 4. Encourage public participation in maintaining water quality and in stormwater management in the basin, including citizen action projects to clean trash from streams and education about citizens role in maintaining clean water and stream systems. S. Perform more detailed and comprehensive hydrologic/hydraulic analysis of all drainage systems within the basin to determine how the existing facilities will function under existing and future flows. G. Prepare a comprehensive basin plan with participation by all agencies concerned with surface water management in the Basin. The plan should assess the econo- mic, hydrologic, and habitat impact of individual projects on a basin -wide scale. P:DR/jr 4 BLACK RIVER BASIN Basin Boundary Subcatchment Boundary Collection Point Stream 0006 Tributary Number 00301 Proposed Project July, 1987 APPENDIX B CAPITAL IMPROVEMENT PROJECT RANKING BLACK RIVET{ BASIN Prior to the Black River Basin field reconnaissance, seven projects had been identified and rated using the CIP selection criteria developed by the Surface Water Management {SWM} and Natural Resources and Parks Divisions. Following the reconnaissance, seven projects remain proposed for this area. They include one new, previously unidentified and unrated project. This displaces one previously selected project, which was eliminated based on the consensus of the reconnaissance team because no problem was apparent in the field. The previous SWM capital improvement project list for the Black River Basin had an estimated cost of $1,250,000, while the revised list increases to an estimated cost of $1,230,000. This 2.4 percent increase in estimated capital costs is due mainly to upward revised cost figures for securing, or acquiring easements over wetlands and costs associated with a new project to solve a previously uni- dentified problem. The following table summarizes the scores and costs for the CIPS proposed for the Black River Basin. These projects were rated according to previously established SWM Program Citizen Advisory Committee: criteria. The projects ranked below are those for which the first rating question, ELEMENT 1: "GO/NO GO," could be answered affirmatively. These projects can be considered now for merging into the "live" CIP list. RANK PROJECT NO. SCORE COST 1 0302" 125 $ 203,000 2 0303" 110 125.000 3 0309 100 26.000 4 0301" 95 345,000 5 0305* 90 116,000 6 0307* 60 309,000 7 0304* 55 151,000 TOTAL $1,230,000 Indicates project was identified by the Surface Water Management Division prior to reconnaissance. P:BR.APB. B-1 3 a o " o A � a a�.�� c c d Q°g o— � c pp u 0` =vs a w G C] 6l 4D g� c > 'a CA � � . G � C ••r. c 3 v 4 C t 3 CL.; - to f3 i v 2 GJ � c z° ws rx 0 c3 Eu° v Uoa o 0 u � c w: O c '" c �. r 0 co c c 0 w .d aw p o V C O c� 0 3 —IPA- 49 �' C w V R G ,r ca 0 Y w O O Op ai G 0 , ,a v w c O: O �• u p c ^p U c v w &. Y c u '? -0 0 0 q � r1'> g6 Cey itti V 3 C t f C 0' � � � E � � w A .� a � c �.� E cc e E O O w O r �^. O a.: u .,Q M U O °C U �• o U QI O!! f%l O o O I i`+. CI C� er] N n V P "m' O C K � u 'Tr• � O � �„ O � � i � O C� _� '� Gu 0 N O. v V� C CS C p v 4� O O O C .:, T i Q W tl C O h E uuell :j c cs o rg -Ztr O G Q U O O G �. m ', > {7 b SSS p G ti h '�. QI -0ci fir, NN m'O h y Vi fJ 0 w G P G N c $ yr r y to � c O 4 O O G.9 3 _Q �., VST r• Q a7 w �. O 2 Z Cp r- 0 �, r O ? pp 4 () G,,, 4 O O (.j Ga 3 rs r s. 4. I% R. .O r= ci .3 u w c� C •C CIj + tom. C C N V.' FG.• C3 r V' ..V hG p 3 a D_ 'GU s .2� cO O tA` v s u 3 ami O y v' O u O ¢. '�. G 3 ,«r,: � � � � � to ,`••'G--, 3 -'= v of G 0 Vr O a t cw i '� v G u m a c m _ • G �^.: "0 wG C O �7 O 67 G G C , O O O t) O w C O w^ O c C v c G o$ O a �O ti�C'Or'w 'Va N OO �• ta.a ryO3 `* C14Cvj .y r SZ, W a gk ;;o (a O D u Q. O s. M Q rr p a .r � � a o p � U T � rl f`I (•Z G o�iii co U 7.0 OTHER PERMITS This section will be completed in Final Engineering. 1WAN.yiuIlLam1:re ran 4 8.0 CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (CSWPP) ANALYSIS AND DESIGN This section will be completed in Final Engineering. 17254.001-TIRAoc 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT This section will be provided in Final Engineering. 17254.001-TIR.doc j Q 0 10.0 OPERATIONS AND MAINTENANCE MANUAL This section will be provided in Final Engineering. 17254.001-TIR.doc