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Home My WebLink AboutSWP272952(4) z U u I -' S-(q S 0 2, t • 5 \,hw 14- �-�c 0 r CL4) zs , 3cl(o ��.,•.C�- PGA UtiY �� Planning/Building/Public Works Department •• , r Transportation Systems Division 425-430-731F Fax: 425-430-7376 1VT�� Municipal Building 1055 S. Grady Way, Renton, WA 98055 To: D S i,'j K A DATE: f O 1 1i 6 - Jos No. "6- c] -l STo Fi9CIL-[ /L s We are sending you M Attached ❑ Under separate cover via the following items: ❑/S'HOP DRAWINGS ❑ PRINTS ❑ REPRODUCIBLE PLANS ❑ SPECIFICATIONS ❑ ORIGINALS D COPY OF LETTER ❑ COPIES DATE NUMBER DESCRIPTION / REMARKS i to /5 O 'vVo Fez 1;0Po5Gp (-0CA-r(,DNS /�-e/= S 7 'otAl,9 -77E e� Tl Es N L i MESSAGE: These are transmitted as checked below: ❑ FOR APPROVAL ❑ APPROVED AS SUBMITTED ❑ RESUBMIT COPIES FOR APPROVAL ❑ FOR YOUR USE ❑ APPROVED AS NOTED ❑ SUBMIT COPIES FOR DISTRIBUTION ❑ S REQUESTED ❑ RETURNED FOR CORRECTIONS ❑ RETURN CORRECTED PRINTS Lld 1 OR REVIEW AND COMMENT ❑ ❑ PRINTS RETURNED AFTER LOAN TO US Copies to: LC5 L/if L I inl1�T ( G✓�o ffi(�t HMG From: r wwke�'I7 IF ENCLOSURES ARE NOT AS NOTED, KINDLY NOTIFY US AT ONCE. I BERGER/ARAM ENGINEERS INC. PLANNING 33301 Ninth Avenue South Suite 300 BERGER/AB" ENGINEERING Federal Way, Washington 96003.2600 E N V I R O N M E N TA L 2061431-2300 • FAX 206/431-2250 E N G I N E E R S I N C. PROGRAM MANAGEMENT MEMORANDUM Date: 15 October 2004 Subject: Proposed Locations for Stormwater Facilities for Subbasin D1 From: Naomi Selove-Schneider Gary Phillips To: Mr.James Wilhoit, PE y J Leslie Lahndt, PhD, PE City of Renton 5th Floor, 1055 South Grady Way Renton, WA 98055 Eight potential locations to construct the stormwater facilities for Subbasin D1 along Duvall Avenue NE were investigated. The criteria for these facilities were based on the Stormwater Management Manual for Western Washington (SMMWW)published by the Washington State Department of Ecology in August 2001. The facilities were sized using the requirements for redevelopment (SMMWW, Vol. I, Ch. 2-10). The project site has approximately 47 percent existing impervious coverage. Both the new impervious surfaces (0.66 acre) and the converted pervious surfaces (0.44 acre) will be treated for both water quality and detention. The treated area will use the "equivalent area"method. This method provides flow control and runoff treatment for an existing impervious surface area. This existing impervious area must be equivalent in size, belong to the same drainage basin, and have similar traffic characteristics as the new impervious surface. An additional hydraulic analysis was performed based on the criteria in the Highway Runoff Manual (HRM)published in March 2004 by the Washington State Department of Transportation. This analysis was performed to determine if there would be a cost advantage in following the criteria of the HRM instead of the SMMWW. There was not a significant cost savings; therefore, the analysis is not included as part of our evaluation of options for stormwater and water quality. The eight configurations investigated are wet ponds, wet vaults, or a combination of both. Two of the options would be built within the City of Renton or King County right of way(ROW). Three of the options involve either a full or partial take of the Tharp property located at 1803 Duvall Avenue NE. The remaining three options involve a full take of the Grass property located at 10733 138th Avenue SE. Below is a brief description of eight options along with the original plan(Option 9) on the Bales property Option 1 This option would involve constructing two vaults within the King County ROW along Southeast 107th Place. The first vault (43 x 20 x 8 feet)would treat 100 percent of the water quality volume. The second vault(150 x 20 x 8 feet) would detain 100 percent of the detention volume required. This Mr. James Wilhoit Ms. Les e ahndt 14 October 2004 Page 2 option would require no additional ROW acquisition. Further investigation would need to be done to determine what utilities are along Southeast 107th Place and any impacts this may pose. Option 2 This option would involve constructing a pond on the Grass property. The two-celled pond would treat and detain 100 percent of both the water quality and detention volumes required. In order to obtain the required volume, vertical walls would be required on two sides of the second cell. A full acquisition of the Grass property, along with demolition of the existing building, would be needed. The Grass property slopes upward from the east to the west side of the property. It was estimated that the change in elevation is approximately 11 feet. In order to construct a facility on this property, the parcel would need significant excavation, which is denoted in the cost estimate as"Excavation (property)"A new wall would need to be constructed on the west side of the Grass property to maintain the elevation of the property to the west. The existing wall on the south side of the property has been removed during construction of an oil changing facility to the south. It appears that this wall will be replaced but it is not known at this time what type of wall will be constructed. This wall would need to be partially demolished. It may be possible to reuse a portion of this wall to construct the new wall on the west side of the property. Reusing the existing ecology block wall was not accounted for in the cost estimate due to the uncertainty of the developer plans for a new wall. Option 3 This option would involve constructing a pond on the Tharp property. The two-celled pond would treat and detain 100 percent of both the water quality and detention volumes required. All sides of the pond would have 2H:1V slopes. A full acquisition of the Tharp property, along with demolition of the existing building, would be needed.. From site visits, it was noted that the property is basically level. Option 4 This option would involve constructing a vault(43 x 20 x 8 feet)and a pond on the Grass property. The vault would contain 100 percent of the water quality volume required. The pond would contain 100 percent detention volume required. All four sides of the pond would have 2HAV slopes. A full acquisition of the Grass property, along with demolition of the existing building, would be needed. The same site preparation tasks (partial demolition of the existing wall, construction of a new wall, and property excavation)would need to be performed as discussed in Option 2. Option 5 This option would involve constructing a vault and a pond. The vault(70 x 13 x 8 feet)would contain 100 percent of the water quality volume and would be constructed to the north of the property under the private roadway, located perpendicular to Duvall Avenue NE, at approximately STA 185+50. The pond would be located on the Tharp property and contain 100 percent of the detention volume required. All four sides of the pond would have 2H:1V slopes. Full acquisition of the Tharp property would be required, as well as demolition of the existing building. This parcel could possibly be subdivided into two parcels The north parcel would contain the pond and the resulting south parcel could be surplussed to offset a portion of the initial acquisition cost. For the cost estimate, the possibility of resale was not taken into consideration. Further investigation would need to be done to determine what utilities are along the private road. Mr. James Wilhoit Ms. Leslie Lahndt 14 October 2004 Page 3 Option 6 This option would involve constructing three vaults under the roadway along Duvall Avenue. The first vault (70 x 13 x 8 feet), located just south of Northeast 18th Place in the center of the roadway, would contain 100 percent of the water quality volume required. It would be possible to construct the water quality vault under the parking lot of the Bales'proposed development There does not appear to be a strong benefit in doing this. The second vault(98 x 20 x 8 feet), located just north of Southeast 107th Place in the center of the roadway, would contain 65 percent of the detention volume required. The third vault (53 x 20 x 8 feet), located south of Southeast 107th Place in the center of the roadway, would contain 35 percent of the detention volume required. No ROW would be acquired but utility conflicts may determine this option to be higher in cost and possibly unfeasible. Option 7 This option would involve constructing three vaults on the Grass property. The first vault(43 x 20 x 8 feet) would contain 100 percent of the water quality volume required. The second(75 x 20 x 8 feet) and third (75 x 20 x 8 feet)vaults would each contain 50 percent of detention volume required. A full acquisition of the Grass property, along with demolition of the existing building, would be needed. The same site preparation tasks (partial demolition of the existing wall, construction of a new wall, and property excavation)would need to be performed as discussed in Option 2. Option 8 This option would involve constructing three vaults on the Tharp property and on the private road to the north of the property. The first vault (70 x 13 x 8 feet) would contain 100 percent of the water quality volume and would be constructed under the private roadway. The second vault(46 x 20 x 8 feet)would contain 30 percent of the detention volume. The second vault would be located perpendicular to the private road and would partially reside on the north side of the Tharp property. The third vault(106 x 20 x 8 feet)would contain 60 percent of the detention volume. The third vault would be located west-east on the north end of the Tharp property. Partial acquisition would be required of a 31-foot-wide strip on the north side of the property. Only this area was taken into account for the cost estimate The existing building would not need to be demolished. Further investigation would need to be done to determine what potential utility conflicts may be along the private road. Option 9 (original plan) This option would involve constructing a pond on the Bales property. The two-celled pond would treat and detain 100 percent of both the water quality and detention volumes required. Full acquisition of the property would be required. We recently became aware of plans to develop this parcel. This option is, therefore, fatally flawed but is provided to you to compare the costs associated with the other options available to us. Further geotechnical exploration will be required for any option selected. If the groundwater table is high, the underground vaults may need an anchoring system to offset the buoyancy. This is a cost that has not been included in any of the options Based on the geotechnical borings we have from the draft geotechnical report, we do not expect to encounter a high groundwater table. Ilk Mr. James Wilhoit Ms. Leslie Lahndt 14 October 2004 Page 4 Sununary The ranking of the options in order of least estimated cost are as follows. 1. Option 3 (Tharp property) -- $209,317 2. Option 1 (County ROW) -- $210,356 3. Option 6 (City ROW) -- $230,628 4. Option 5 (Tharp property) -- $251,396 5. Option 8 (Tharp property) -- $286,729 6. Option 2 (Grass property) -- $302,310 7. Option 4 (Grass property) -- $338,832 8. Option 7 (Grass property) -- $443,006 Option 3 is the least expensive with Option 1 coming in a close second. Although these two options are close in price, Option 3 would be the most preferable of the two. Option 1 will have more long-term maintenance costs and increases the potential for utility conflicts. Option 5 is the fourth lowest in cost, but the estimate excludes the $48,000 that may be recovered if the property was to be subdivided and resold. Both Option 3 and Option 1 have a $130,000 approximate savings over thoriginal plan of utilizing the Bales property. BERGER/ABAM recommends the City accept Option 1 because it entails no need for additional ROW and still saves nearly $130,000 in construction' ts:' Thank you. ? NAS/GLP:kjr Attachments cc: Kelly Robinson, BERGER/ABAM COST ESTIMATE ITEM UNIT UNIT PRICE QTY COST Option 1 --County ROW Property LS $0.00 0 -- � "ii� b J,l,� Building LS $0.00 0 I Building Demo LS $0.00 0 J c� Vault(100%WQ) Excavation(property) CY $15.00 0 Vault(100%Detention) Excavation(vaults) CY $15.00 1,605 $24,078 Back Fill CY $30.00 286 $8,578 11 JI V Y3 J Wall SF Vault(43x20x8) EA $38,700.00 $38,700 / Vault(150x20x8) EA $135,000.00 �� $135,000 Flow Restrictor MH EA $4,000.00 1 $4,000 $210,356 Option 2--Grass Property Property LS $85,000.00 1 $85,000 Building LS $118,750.00 1 $118,750 Building Demo LS $10,000.00 1 $10,000 Partially Remove South Wall LS $5,000.00 1 $5,000 Pond Excavation(property) CY $15.00 1,947 $29,211 (100%WQ&100% Excavation(pond) CY $15.00 1,279 $19,179 Back Fill CY $30.00 0 Wall(property) SF $30.00 880 $26,400 Wall(pond) SF $30.00 159 $4,770 Flow Restrictor MH EA $4,000.00 1 $4,000 $302,310 Option 3--Tharp Property Property LS $96,000.00 1 $96,000 Building LS $80,000.00 1 $80,000 Building Demo LS $10,000.00 1 $10,000 Pond Excavation(property) CY $15.00 0 (100%WQ&100% Excavation(pond) CY $15.00 1,291 $19,371 Back Fill CY $30.00 0 Wall SF $0.00 0 Flow Restrictor MH EA $4,000.00 1 $4,000 $209,371 Option 4--Grass Property Property LS $85,000.00 1 $85,000 Building LS $118,750.00 1 $118,750 Building Demo LS $10,000.00 1 $10,000 Partially Remove South Wall LS $5,000.00 1 $5,000 Vault(100%WQ) Excavation(property) CY $15.00 1,947 $29,211 Pond(100%Detention) Excavation(vault) CY $15.00 367 $5,500 Excavation(pond) CY $15.00 957 $14,360 Back Fill CY $30.00 64 $1,911 Wall(property) SF $30.00 880 $26,400 Vault(43x20x8) EA $38,700.00 1 $38,700 Flow Restrictor MH EA $4,000.00 1 $4,000 $338,832 Option 5--Tharp Property(50%) Property LS $96,000.00 1 $96,000 Building LS $80,000.00 1 $80,000 Building Demo LS $10,000.00 1 $10,000 Vault(100%WQ) Excavation(property) CY $15.00 0 Pond(100%Detention) Excavation(vault) CY $15.00 367 $5,500 Excavation(pond) CY $15.00 1,019 $15,284 Back Fill CY $30.00 64 $1,911 Wall LF 0 Vault(43x20x8) EA $38,700.00 1 $38,700 Flow Restrictor MH EA $4,000.00 1 $4,000 $251,396 Option 6--City ROW Property LS $0.00 0 Building LS $0.00 0 Building Demo LS $0.00 0 Vault(100%WQ) Excavation(property) CY $15.00 0 Vault(65%Detention) Excavation(vaults) CY $15.00 1,850 $27,744 Vault(35%Detention) Back Fill CY $30.00 291 $8,733 Wall LF 0 Vault(70x13x8) EA $50,750.00 1 $50,750 Vault(98x20x8) EA $88,200.00 1 $88,200 Vault(53x20x8) EA $47,700.00 1 $47,700 Flow Restrictor MH EA $4,000.00 1 $4,000 By-Pass Flow MH EA $3,500.00 1 $3,500 $230,628 Option 7--Grass Property Property LS $85,000.00 1 $85,000 Building LS $118,750.00 1 $118,750 Building Demo LS $10,000.00 1 $10,000 Partially Remove South Wall LS $5,000.00 1 $5,000 Vault(100%WQ) Excavation(property) CY $15.00 0 Vault(50%Detention) Excavation(vaults) CY $15.00 994 $14,911 Vault(50%Detention) Back Fill CY $30.00 175 $5,244 Wall(property) SF $30.00 880 $26,400 Vault(43x20x8) EA $38,700.00 1 $38,700 Vault(75x20x8) EA $67,500.00 2 $135,000 Flow Restrictor MH EA $4,000.00 1 $4,000 $443,006 Option 8--Tharp Property(25%) Property SF $15.00 4,089 $61,335 Building LS $0.00 0 Building Demo LS $0.00 0 Excavation(property) CY $15.00 0 Vault(100%WQ) Excavation(vaults) CY $15.00 1,671 $25,067 Vault(30%Detention) Back Fill CY $30.00 293 $8,778 Vault(70%Detention) Wall SF 0 Vault(70x13x8) EA $50,750.00 1 $50,750 Vault(46x20x8) EA $41,400.00 1 $41,400 Vault(106x20x8) EA $95,400.00 1 $95,400 Flow Restrictor MH EA $4,000.00 1 $4,000 $286,729 Option 9--Bales Property Property LS $313,400.00 1 $313,400 Building LS $0.00 0 Building Demo LS $0.00 0 Pond(100%WQ) Excavation(property) CY $15.00 0 Pond(100%Detention) Excavation(pond) CY $15.00 1,520 $22,803 Back Fill CY $30.00 0 Wall SF $30.00 0 Flow Restrictor MH EA $4,000.00 1 $4,000 $340,203 u- I ----__ --__—__ - - I 7 FLOW RESTRICTOR ► m ► ---------J I I Ij I o ►---------- j OPTION 3 POND 100% WQ 100% DETENTION I ► _ ► OPTION 1 VAULT OPTION 2 POND I I 150x2Ox8 100% WQ I 100% DETENTION —— — -—--— _� --— j100% DETENTION ► — — � I I ---r - - ------ - I- I I i - I � ►► ,I j � l I ► I OPTION 1 VAULT —1 43x20x8 I 100% WQ ^/ I I w I i I I I I FLOW IRESTRICTIOR FLOW RESTRICTOR ■ I I`► I �t - - -I- - 17 9+00 a -09 -�;-;—�J9 r 99 19 4-a-9-9 -� 1�-� I-{39 'Q a I V/ k, ti, r - - - - - - - - - - - - - - - — 1- - - - - - - - - - - - - - - - - - - - - - - - - - - - - � \ — — — — - - - - � 0 25 0 25 50 1"=25' scale feet ".,....,.s 33301 9TH AVENUE SOUTH , 1 =zs ��' A DUVALL AVE NE/COAL CREEK PARKWAY SE 10/15/04 ,. "~` FEDERAL WAY,WASHINGTON � � N ON RECONSTRUCTION PROJECT _ ,. rnmoe 98003-2600 E N G I N ER/ABAM VOICE: 206 31-2300 r�s � DATUM °"q 10 ( 14 Planning/Building/Public works Deft. PROPOSED LOCATIONS FOR FIG-1 f.s FAX: (206)431-2250 NO. REVISION BY DATE APPR STORMWATERFACILITIES ' ` 1 "3 N 0 LL I I I I - ----------------- l I I 1 I o r Z 1 I I OPTION 5 VAULT 0 OPTION 4 POND I = I I 1 100% DETENTION I I I I OPTION 5 POND 100%% WQ 100% DETENTION --- FLOW RESTRICTOR I I I OPTION 4 VAULT I I i i I I I 43x2Ox8 I 100% WQ I I FLOW RESTRICTOR /I OPTION 6a VAULT r I i I I 70x13x8 i FLOW RESTRICTOR - - - - - - - - - -- I- 100% WQ _ - I- - - - - - - - - - - - - - - - - - - - - - - rl ---- -------- ----- - ------+00 7 — - - � - - - - - - - - - - - - - — — — — — — — — — — - - - 0-4 - - - - - - - - - — — — — — — — — — — — — — — — — — \ OPTION 6 VAULT I OPTION 6 VAULT I / 53x2Ox8 88x20x8 —' a \ 35% DETENTION I 65% DETENTION I I OC) \ I OPTION 6b VAULT i I 70x13x8 I 100% WQ II i I I I I I I I I I I 25 0 25 50 1"=25' iiii scale feet 33301 9TH AVENUE SOUTH ..Mm =zs' "� DUVALL AVE NE/COAL CREEK PARKWAY SE 1o/15/0+ CITY OF FEDERAL WAY,WASHINGTON MAS RECONSTRUCTION PROJECT ecRcee�aean� 98003-2600 a... RENTON VOICE: 206 1-7d00 � DATUM «ac Na ( )� Planning/Building/Public works Dept. PROPOSED LOCATIONS FOR FAX: (206)431-2250 NO. REVISION BY DATE APPR STORMWATERFACILRIES FIG-Z 1 -3 r s,..w o,w ar�a zav or asq[av ar sdoK rx m . o Ixarlr�prr-a-aulamldm lv a wrnzla_�m�e.o sad:r . •r� j I Z I 'I . LL I -------1 1---------- - ----- I I I -' - OPTION 8 VAULT C) I 46x2Ox8 I I I i 30% DETENTION I = j OPTION 7 VAULT I I I 75x2Ox8 50% DETENTION I I I I - _T z __ OPTION 8 VAULT FLOW RESTRICTOR I I---------- I I 70% DETENTION I I --—- ) OPTION 8 VAULT L--------------- I j j j j 70xl3x8 II 100% WO OPTION 7 VAULT I I I 50% DETENTION I I I I I I I OPTION 7 VAULT i j 100% 8 I I I I I I i 00% WO I FLOW RESTRICTOR 'I i - - - - — � - - �— - - - -I- - — — — — — — — — — — — — — — — — — — — — — — — — — — — — 179+00 - - - - - - - � - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - —� — - - - - � z / - - - - - - - - - - M / M -� W T rV 1 25' 25 0 25 50 1•'= scale feet 33301 9TH AVENUE SOUTH 1'=25' CITY OF DUVALL AVE NE/COAL CREEK PARKWAY SE 10/15/04 FEDERAL WAY.WASHINGTON NAS •+ RENTON RECONSTRUCTION PROJECT _ 98003-2600 B��/�_�� VOICE:(206p131-23DO ...�"� f—A DATUM Play ri9/eund y/Pubrc worms Dept. PROPOSED LOCATIONS FOR FIG-3 FAX: (206)431-2250 NO. REVISION 8Y DATE APPR STORMINATER FACILITIES ' ' 3 '3