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HomeMy WebLinkAbout2004-03-05 NAC Planning Report .G -lk- 1 NORTHWEST ASSOCIATED CONSULTANTS, INC. tiJ . ,; :., ,., -,• i k l i liii i lit I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I k I 1 1, 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 11 1 111 1 1 1 111 1 1 1, 1 1 1 1 1 1 1 1 1 1 111 1 1 11 1 1 1 1 11 11 1 1 1 1 1 l i i i i i i i i i i i i 1 ii i i i i i i 1 1 ii 114 ii 114 i iii. i iii i 1 ii 1 1 1 ii ii 1 k i i i i i i i ii k i i i i i i i i k i i i ii ii i i ii iii�ii��iiiii�i�iiii �i,Ir 5775 Wayzata Boulevard, Suite 555, Bt. Louis Park, MN 55415 Telephone: 952.595.9536 Facsimile: 952.595.9837 planners@nacplanning.com PLANNING REPORT TO: Eric Johnson FROM: Cynthia Putz -Yang 1 Scott Richards DATE: March 5, 2004 RE: Oak Park Heights -- East oaks PUD 2nd Addition: PUD concept Plan FILE NO: 793.02 -- 04.04 BACKGROUND River Valley Rentals, LLC is requesting approval of a Planned Unit Development (PUD) Concept Plan for a development called East Oaks PUD 2 Addition. The development is proposed to contain one 32 unit residential condominium building, one 2,100 square foot office building, and one 5,230 square foot office building. The site area is east of Osgood Avenue and south of Highway 35. Attached for reference: Exhibit 1: concept Plan Exhibit 2: condominium Building Elevations Exhibit 3: Office Building Elevations ISSUES ANALYSIS Comprehensive Plan. The entire project area is designated as commercial land use. The comprehensive Plan land use map should be amended to address the residential land use if this project moves forward. Zoning. The property is zoned B -2 General Business (north) and R -B Residential /Business Transitional (south). A PUD is a conditional use in those districts. The use of the PUD allows multiple buildings on one property with shared parking. The current zoning is consistent with the proposed project. Surrounding Land Uses. To the south of the project site is the East Oaks townhome development. To the east is club Tara and the Xcel Energy ash disposal facility. To the north is Highway 35 and to the west are apartment buildings. Phasing. The concept plan shows that the proposed residential condominium building will be in Phase 1 and the proposed office buildings are in Phase 2. The applicant estimates that Phase 1 will begin September 1, 2004, and be complete by December 31, 2005. The applicant estimates that Phase 2 will begin May 1, 2006, and be complete by June 1, 2007. Market. The applicant has provided the following description of the project: Phase I: A condominium building consisting of 32 units at a target price range of $180,000 per unit average. Three stories with 14,000 square feet per story and an additional 14,000 square feet of underground parking. An elevator serves the parking and three levels of living. Forty -five outside parking stalls for condos. The outside amenities include a pool and patio area, tennis court, and small picnic area near existing holding pond. Possible enhancing of the holding pond. We expect the demand for real estate under $200,000 to increase as property value continue to rise in this area. We feel this is consistent with the city's comprehensive Plan for mixed use in this area. Being residential and office space. Phase ll: office building(s) on 60 Street. one approximately 5200 square feet, the other approximately 2200 square feet. After this description was written, the applicant found that there was not enough open space for a tennis court. The only outside amenity illustrated on the concept plan is a swimming pool surrounded by a patio. Density. section 401.15.C.3 of the Zoning Ordinance requires 2,500 square feet of lot area per multiple family unit. In the R -B District, apartment density bonuses are available to allow a maximum 20 percent reduction in square feet of lot area per unit for multiple family dwellings of ten units or more. Bonuses are granted for features such as type two construction, elevator serving each floor, and one -half of the required free parking underground or within the principal structure. The concept plan shows a total of 55,287 square feet (39,543 + 16,744) of lot area devoted to residential or common open space. The basic requirement of 2,500 square feet of lot area per multiple family unit results in a maximum of 22 units being allowed. If the building is type 2 construction with an elevator and underground parking, up to 25 units are allowed. The applicant must submit additional information to determine what density bonuses apply. In any case, the maximum density allowed has been exceeded, and the number of units proposed should be reduced. 2 Setbacks. The front of a lot is defined as that boundary abutting a public right -of -way having the least width. The roadway along the west boundary is a private road; therefore, the only boundary with frontage on a public road is the north boundary. The front yard setback requirement in the B -2 District is 40 feet. A setback of 25 feet is proposed. The Planning Commission should comment on this arrangement. The proposed setbacks may be allowed as part of the PU D and may be considered appropriate because the property will be fully developed with this project and the buildings will be set back over 60 feet from the pavement of 66th Street North. The project complies with the minimum side yard setback of ten feet on the east side of the property. Flexibility is being requested to allow a side setback of five feet, rather than ten feet, from the west property line. The Planning Commission should consider whether this setback is adequate given that the proposed condominium building is three stories high plus a sloped roof on this side. Similarly, flexibility is being requested to allow a setback of 21.3 feet from the rear, south property line, rather than the 30 feet required in the R -B District. This side of the building is even taller than the west end because the ground slopes away to the east. Even with evergreen screening, this height appears to be excessive for a reduced setback. Building Height. The maximum building height allowed in the R -B and B -2 Districts is 35 feet measured from the mean ground level to the midpoint of the roof. The condominium elevations indicate that the distance from the finished main level to the roof midpoint is 36' -6 ". The distance from the ground level in front of the underground parking garage door to the midpoint of the roof is 48 feet. We do not have enough information to determine the mean ground level; however, in any case, the maximum height allowed in the R -B and B -2 Districts has been exceeded. We recommend that the condominium building be reduced by one story because, as proposed, the project requires flexibility from density, height, and setback requirements. Landscaping and Tree 'reservation. General tree cover is illustrated on the concept plan. A detailed tree inventory and landscape plan will be required with the general plan of development. Grading, Drainage, and Utilities. At the time of this writing, additional information is needed in order for the city Engineer to comment on grading and drainage issues. The applicant is requesting that part of a drainage and utility easement be vacated to allow construction of a swimming pool and retaining wall. The applicant is also proposing to add fill on top of an existing sanity sewer pipe. The applicant must provide information about this pipe's ability to accommodate the additional weight. comment by the city Engineer is needed regarding these concepts, which are significant components of the design. Exterior Building Materials. Proposed exterior materials are rock face C.M.U., cultured stone, and vinyl siding. Steel siding or Hardi -board siding is preferred over vinyl siding. 3 Parking. At least 2 spaces are required per multiple family dwelling unit. Therefore, at least 64 parking stalls are required for the 32 --unit condominium building. Three parking stalls plus one parking stall per 200 square feet of floor area are required for each office building. If appears that there is floor area on two stories of each proposed office building. This should be clarified with floor plans. Based upon the building areas indicated on the concept plan, 13 parking stalls are required for the smaller office building (2,100 x .9 1 200 sq. ft. + 3), and 27 parking stalls are required for the larger office building (5,230 square feet x .9 1200 + 3). The total required parking for the site is 104 stalls. The concept plan includes 121 stalls, 41 of which are underground. Condominium Trash Enclosure. With the general plan of development, the applicant must submit trash enclose details. The trash enclosure materials must be consistent with the materials used on the condominium building. Lighting and Signage. with the general plan of development, the applicant must submit information related to lighting and signage. RECOMMENDATION The Comprehensive Plan designates this area as commercial, while the zoning separates the property into commercial and residential /business districts. If residential use is approved for the site, the Comprehensive Plan map will need to be revised to address the use. While the use, as proposed, is consistent with the zoning and surrounding land uses, there are a number of outstanding issues with the concept plan as proposed . Density, setbacks, building height, and engineering issues will need to be resolved before the concept plan can move forward. The Planning Commission should comment on the proposed setbacks and the possibility of exceeding allowable building heights through the PUD process. we recommend the Planning Commission review the project, make comments, request additional information as necessary, and continue the project to the April meeting. 4 EAST OAKS F> . U . E:>. �ro I AS7E30LlNCJ I STATE T-RU NK HEGHWAY N O. 36 41-5 J 2ND ADDITION --- ------ EXHi BIT 1 -ET NORTH 6 T H S T R.-E X JEFF HAUSE S89"48'04"W I*z RIVER VALLEY RENTALS, LLP 1937 SOUTH GREELEY STREET 5&0 STILLWATEP, MN 55082 - Phone: 651 -77S -0587 ----- ---- 4 4 ew eel m CITY - COUNTY: P2070%_O�la sm YARD 7S J�AH 2 CE PROPOSED dkFl 117= in in (z i - �9. � f j 2S OA�K PARK GHTS HEI 2S me- exz WASHINGTON, COUNTY o WICAON: -n CER A �30 A7 I harebwr corMy ha th1r. plan wo oftwod that I am a duly Wimased LandSurvtycf • CD by rm, or unda t my d mmuvw sm! $ 20 under *4 Wnwx erf the scam a( IAW*WTA- _b.KftILThUfwbnR*j0Ar&bDnN0: 25718 Gr) REVISIONS: PROPOSED -- �°� -�UN1Tz6NDOMiN1[JM PARKING REOUIRMENTS: DAn n-MSCK %%_ f3 S fL >> + 12-23-0 comer StISWITAL - RtVMD SM OFF= SPACE KUDING*1 5.230SQFT. I 2DDSMFT+ 3 2 2-25 ­" -04 CITY MEEM CONCEPT G CHANGES ITTAL r 29.1 STALLS RUILOM 92 - 2.101) MFr• 1 200 SOFr + 3 13.50 D1. 4 STALLS PROPOSED USE: '7 < PRO PESIDENTAX - 32 UNFTS X 2 UNITS - 64 STALLS e TO TAL REQUIRED STALLS - 106.65 STALLS x- d�ylts L 0 PL-461" " 1= NUMBER OF STALLS PKMDM - 121 STALLS C> aNg'EL_<> P M F_ FV I ic - MAWACE U'rLIT'y EA3EtEN PHASE I REWIRED STALLS - 64 PHASE I PROVIDED STALLS 65 67, N L= 72-79 GARAGE PARKING PLAN: 4 I STALLS .5 T7 9' i i 0 30 60 NORTH 4,37 0 A s-rw E-Y,[ z rj N � a c-yj5T1f4c Em-mc r=x63,4 TWWOME, TWNHOM ''1 � � ' I 1 r RXI Tvc rww TWWOM TWWOME , TWNHONe MN40M� Tw k440M PLAN 7 112 SCALE 1 9012 South Gmlay $imat + Suke 93 GWOr ElMffi SumNater, MN 55082 Dhow esi=Am Fox 651.27,'LW75 VICINITY MAP - NO SCALE, SYMBOLS: SURVEY NOTES: DMLOPMENT DATA: dk-=kQ <+/\ SECTION 4,TOWNSHT?29, RANGE 20, BASIN 1, USE DETAIL, mdoodusm tp CATCH MANHOLE K HYDRANT 7. BLAMICS ARE BASED ON TKE PLAT Of CAST OAKS P.U.D. V CURRENT ZONING P.U.D. WASHINGM COUNTY ix CULVERT SIGN 2- LEGAL DESCRtPTFON PROVIDED BY THE OWNER. ZONED 82 AND PLAN FENCE WATER VALVE HWY, 36 60TH ST. FENCE LmLmPm 3. EASEMENTS SHOWN PE&COUNTy HALF SEcTKw mAn oft 1 3 SCALE CONC LICHT POLE RETE KECORD PLAT. OTHM E&SEMEWM IF ANY. MAYEXISZ A PROPOSED USE - 32 UNIET CONDO B UILDING AND 2 GENERAL, OFFICE DENOM FOUND EL ROX ARE NCITSHCWN ONTHISSUIVIAX WILDING& I Ir " PIPE; MALW 4. TOPMRAPHY FROIV WASMGTON COUM ORTHO PH10M OVERMEADVdtF4 DATMAPRIL2000. PROPOSED SErBAIC13 ARE SHOWN ON DRAWING. o DENOTO SET 1 12' IR1W _r.' 71� Ell --- LJ WELL comtw"CaX PIPEMAMMIKLS2S719 49,049 S ft. CORNERSTONE AREA, ................. , L_4k1N t> SURN/177'INC. INC TOTAL AREA OF PARCEL = 104,3S7 SIIFT. 1 7.396 ACRES CALL 11.01M YOU =1 RESDOMAL 39IIS4� s I& K TREE CDM BAS ON OKM PHOTO EXISTING LEGAL DESCRIFFION: Gopher State One Call \ �t 4/ TWNCrryAXFA' JNYi-4S4-*= TmTRm 1-800-2S2.11cs COMMOK PROI= Na. JH030M OUTWTA. EAS717 OAXS P.U.D. WAS14NCTDN COU?M. fr- 07 MINNESOTA. CONCEPT PLAN AR THE ARCHaBCrURAL NEf WORK, NC ARCHITECTURE ' PUNNING; 1NTOWR DESIGN' COWMUCTO WWNAGEA04T 12445 5% STREET SWE A LAKE ELMO. UN. 55042 PHONE 651/430 -0605 { FAX 553/430 --0180 v �u sl f 9, If 9% E .....� � � _ ! r. • � II • — � - ��� i _... -�� ._.... � , - -. r _. ..�. �. 11 4 P ... _ _ __�w _ -� _ - A'"a°" 7 _•in 7 r <.... _ .. -- � �f �`^ 1s --- ,.J,r� ��` ir h yr++reh. I '"�•-o+� . �` .wiry � �'- _�.'�F+/n�y '<� ��_ w Ma EES ����il��l(ll�liii �i�llj fl � �iiili��l��iii���«l i(f#il l;��r . - SR' •: ;�"' (/ \� V Project � ELEVAT[03� sra• • s' EAST OAKS P.U.D. .+a.a 2ND ADDITION JEFF HAUSE OAK PARK t 6665, M {3P,VI3iPTIS , Item Date A+t°HPdiT 9FAIYA,�S MSt7PptN7 A A, p DQN4R37 iVEL _ +� ,�� ._ ,.�� �-. t •,fir. �._� ,`. ,� LL - ---- L2�'-0" g . - - • i- - �'--' rte. r �� - �,-.,. .: r' -�Yf' �K: ��(/ !S \,q` ^`• y3�..- YIHYI. 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ARCHITECTURE F PLANMIKV was WTEIIDR DESM ■ CDRSTRUCT101,I MAWLEMENT 12445 551h STREET y� SUITE A LAKE ELMO, MN. 55D42 PHONE 651/43D -D606 FAX 651/430--MW }- ..tea - - v vi m�ery ► - --,.�.. ��i r S'� -. _ . '�F mv� - /ins./ ..i y, ��� - -• J . _ .... ' Vptyt. SFCI!!fi ............ : /.•.'I I ..... ,..,,. �, ,.,� ...,��,,.��, �,,.�� . " ,.I. - .... .. ,. , ...............,,....,..i EXHlBiT 3 T ` -- I f4 1ii l I - ` - �prri=st�a, ccl.olz� souTH ELEVATION „°` ' "' �4 1 ry - �..,,.., \ ) rnr G/ a ,r• •i • r n i \'vrT / /la n%a / �Cl - fi4f✓f�t% ". - •w •s a+� s� -r. n -,w .. �7ii� �k.. - P roject C JT QYyK RU D. 1 I� � 2NQ A VIT1ON - — - _ • � -- . � - • ... .. ' ....: . -' ..... _ _. , ,�. rte... < . / ,` , .. � �1�1 OAK PARK FM*n, MR Revisions ltem D ate (EPS5T ELEVATION a Ve5T ELEVATION 7 ^'�••Ir 1 { - 4J?.'�l_ - •1'? .91 \Y: �n��y��}, N \ / • -`• ••.R1.N.�"\ •- ! ' �.�� •� dem registration Informa r. .,, ', I �ru.i� - r..��.. _. f \ :: �1 •__ _ I hwd)y &,rktry !hat"pldt, spoak=UoN or report xps � b5 me x radar wy r�lrezt - a,pervisk) !Slat i ram a ; r AwdAwl t ~ the k" of tram State of - � Mlkrlescta. 0 NORTH ELEVATION Prrei �e .ins tte Ira• . Ib" 5kr+aturar hate, ape s, Sheet Information EMAMONS Project No : W-M terming No Dote : sr}12t�74 • � I I i I li i illl illl AR CHNE T THE NETWORK UqC ARCHITEMRE " PLANNING" INFERIOR DESIGN ! CON'MUCIiON MANAGEMENT T2445 55th STREET SUITE A LAKE ELMO. MN, 55042 PHONE 651/430 -0606 FAX 651/430 -0180 (` I.1 11 I 1 16.1 11 1— iii 11 1 �4 1 /may —'-�� t_ ��."ah"' ....i.. �5�:,...a' -.<�' � \or'4� K"` • =.1 i. ..� -:sr' - r _., VIi7YL x1r7iH6 L li I .H it 1 i �\ >I�a } '--a, AL WU::R ROCXFACr GMEf. �50UTH ELEVATION - OFF €CE B A I b 4.1119 11 1 Yi1 Y. I.i yYl i 11 11 .dil IW AIIIH�dumiG Projact -LIZZ4 F_A5T O AKS P.U.0, 2ND ADDITION '': vii r .:. w � _ — - JEFF HAU5E f11 �11f Iif1 Ell fi�'� =_ OAK PARK H�16HT5, �N AO 11 1 i i Y LA 1 �i1i I i � d 1,, AgYl Wi ilO.i i Item Dote � >=A5T ELEVA71 - OFHCZ 5 NE5T ELEVAT - OFFICE :3 ..�.[ VW t I.-0. i I 11 1 it l e i YI i ilin 1 it iO IinYYU. �4 Registration information 1 harWy wr[Ify t31at tFrM plan, epocif lwtbn a repor[ — prap --d q mo- a u�dor my zoct [Slorl, �, i _ . ri�wwr�ri_•!I�s,Arilrui�IM. - • rl�: �--- aupery and that i crn n (104 l.rccrroad Arch4ect wader the lams of Mi State of -'1 m 5lgnature: Datei Lkers.p A NOiP,TH ELEVATION. — OFF €GE 5 J�.1 118' >: rte• Sheet information CON= Ef MATIONS ProjciA No 06-117 Drawing No Drain : Ft7lt �. y Chocke 9y K I-0r7'LL'R We a/=004 02004 The Architectural Network, Inc. March 5, 2004 STEVENS E N G I N E E R S Mr. Jeff Hause River Valley Rentals 14210 1 01h Street North Stillwater, MN 55032 Re: East Oaks Development -- Storm water Management Plan and Pond Alterations Dear Mr. Hause: This fetter is a summary report on our findings and recommendation on the subject of the storm water pond design for your proposed amendment to the East Oaks PUD. The City of Oak Park Heights requested that we address the question of whether the existing pond will need to be increased to handle the additional hard cover on the site. we have done that and determined that the existing pond must be increased in size, the outlet pipe must be replaced with a larger pipe and an outlet structure, but this can be accomplished within the parameters of the site plan as proposed. The revised storm water pond and outlet will meet current design standards for storm water ponds. The design of the existing pond included the total area of the PUD and immediate tributary area. However, the runoff' curve numbers did not consider the amount of hard cover proposed for this project. The existing pond has a 21" diameter RCP pipe outlet. This is connected to the existing 36" storm surer that runs through the site. Our calculations and concept design indicate that we can maintain the existing peak rate of discharge to this storm suer by expanding the pond and by replacing the 21 outlet pipe with a 24" pipe and an outlet control structure. We used HydroCAD TM software to model the runoff and pond routing. The commercial outlot proposed for development is not now routed through the pond. This is shown in our existing condition routing schematic. we routed the flours to the existing 36" storm suer for purposes of computing summed hydrographs to compare existing and proposed flows. After development, the outlet runoff will be routed through the pond. This is shown in the proposed condition routing schematic. The schematics and flow summaries are attached to this letter. JIMAMY DOCUMENTSIJEFF HAUSE 030504.DOC 50 1656 Livingstone Road ® Hudson, WI 54016 715- 386 -5819 • 651 - 436 -2075 l 800-822 -7670 * fax: 715 -386 -5879 o www.stevensengineers.com We will be available to answer your questions regarding this subject at your meeting of March `l 1 1 h. We are available to discuss this with your staff at their convenience. Sincerely, James P. DeEenedet, P.E. STEVENS ENGINEERS, INC. enc. c. Eric Johnson, City Administrator Dennis Postler, P.E., City Engineer Mr. Jeff Hause March 5, 2004 Page 2 .4R is C Outlot istin 36 in Pipe V / S b I 3 P _......, Pond 1 a y �x a�^czr.�r+:a.arxczsra. Twinhome Area �'r^•- *- �..w.�.. -; ��+"M.......w.�..w � ill i i ii � i ii I. Lei l�i�ii�� iii �i iii .i i n�iiiiai�einiioieiie IkIN -11. iii�i ii ni ........ '"Iiiki ni '11-H... iiii Dili iioi i iii.... I, k".01i ii 1 kii ik i i ii ii ii iiiiiiiiiiI ii I- i�i�i IIIiiiio i o iii iniioiii i�i�ii iiii��i�iiiiii���i ......i�eii�". i. ni � t Drainage Diagram for East Oaks Exist 2004 L,Subcaf/ Reach on Link Prepared by {enter your company name here} 3/4/2004 HydroCADO 7.00 sfn 002721 019$8 -2003 Applied Microcomputer Systems „, , East Oaks Exist 2004 Type /I 24 -hr 100 Year Rainfall =5.90" Prepared by Stevens Engineers - JPD Page 7 HydroCADO 7.00 sfn 002721 D 1985 -2003 Applied Microcomputer Systems Q 315/20 4 9:09:35 AM Time span =5.00 -24.00 hrs, dt =0.05 hrs, 301 points Runoff by SCS TR -20 method, U P =SCS Reach routing by Stor -Inds -Trans method - Pond routing by Stor -Ind method subcatchment IS: Commercial outlot Runoff Area =2.330 ac Runoff Depth =2.50" Flow Length =750' Tc =9.8 min CN =70 Runoff =9.70 cfs 0.485 of ubcatchment 2S: Twinhome Area Runoff Area=5.970 ac Runoff Depth =3.04" Tc =10.0 min CN =75 Runoff =29.70 cfs 1.514 of Reach 4R: Existing 36 in Pipe Peak Depth =0.82' Max Vel =15.8 fps Inflow =24.44 cfs 1.977 of D- X35.0" n =0.013 L =500.0' S=0.0500'/' Capacity =149.14 cfs Outfiow=24.28 cfs 1,975 of Pond 3P: Pond 1 Peak Elev =844.58' Storage = 17,598 of Inflow =29.70 cfs 1.514 of 21.0" x 98.0' Culvert Outflow =15.27 cfs 1.493 of Total Runoff Area ® 8.300 ac Runoff volume = 1.999 of Average Runoff Depth = 2.89 " „, - - -- � -- , �,,::7v l - :: - V - rug: -, � iiJ�u���� w ”` Y'( uw � r �. �. �. w.,. �,. uw�u, L, �deitw.,. uoi. ��». sA1 �,. L, ���., r,,, ��.,,,.,.,,.,. ��w�ul�, �::: 1J�:. is�uua u' l�iu; ti' u �w; �. � �» ��� �. wt ,, .d'6l'tul�i'?/�Uia1L.w , �fo . =. - -- - .. w/ - - . �, Y , , ..�. .. _. �ww. r u. w�a�: �w, �rc�+r,w.www.w.urW.,�Luli��WO�I CJI�h uw. � al. �r�u �•,T .. ... .. ---•� �. ,<.......... ...,.... ..._�..._._..._..._ ... .. ..... . . . .._.........- ... -.,. ,- .... -- ...,, wawau.+ .'4R is � C omm e rc i al Out istin 36 in Pipe EXi s i 3 �.p Fond 1 Ar 6 f Twinhome Area ♦ � i , iii,i��i�ii�iiiii,i , i 111141... 1.., 1'k 1. N k 1,iii kiiii k iiiii. iiii 11114 I'll iiiii ii fill I'll 1, iii iiiiii iii iii I'll 1. 1,11,1111,lk 11. I'l, iii iiiiii ik IIi k1,i'Ikl"'lP1, iiiiiii k iii iiiii, i, 1, Ilk ii,ii,�, iii„ �i, ii ,�i „i�„i��,�ii�i�,iiii�i,�ii�i f (Subvaf� Reach vnd Link Drainage Diagram for East Oaks Proposed 2404 Prepared by Stevens Engineers - JPD 3/5/2004 •�° .. HydroCAD9) 7,00 s/n 002721 0 1988 -2003 Applied Microcomputer systems iii „ii'k 11, 111. 1,1 iii, ,, i, ii,,, I., d„.i „ii ................. . , 1 , k 1 1 , 111 , 111111111111 iii ,i iI'm i, "I''k -,I iii, lull.... ii, III iiii I-I i i i i i iii i i i i i I I I I i i i i i East oaks Proposed 2004 Tye 1! 24 -hr 100 Year Rainfall =5.90" Prepared by Stevens Engineers W JPD Page 14 HydroCADO 7.00 s/n 002721 @ 1985 7 2003 Applied Microcomputer Systems � :28 :1 7 AM, � ��20�4 9: Time span =5.00 -20.00 hrs, df =0.03 hrs, 501 points Runoff by SCS TR -20 method, UH =SCS Reach routing by Stor -Ind +Trans method - Pond routing by Storwind method ubcatchment IS: C ommercial Outiot Runoff Area =2.330 ac Runoff Depth=3.53" Flow Lengtth =750' Tc =5.2 min Ch1 =81 Runoff =15.71 cfs 0.585 of subcatchment 2s: Twinhorne Area runoff Area =5.970 ac Runoff Depth =3.04" Tc =10.0 min DN =76 runoff= 30.10 cfs 1 .514 of Leach 4R: Existing 38 in Pipe Peak Depth =0.78' Max Vet =15.1 fps Inflow =21.92 cfs 2.156 of D =36.0" n =0.013 L =500.0' S =0.0500 '1' Capacity =1 49.14 cfs Outflow =21.88 cfs 2,154 of Pond 3P: Pond I , Peak Eleu =845.44' Storage= 35,301 cf Inflow =43.44 cfs 2.199 of Outflow =21.92 cfs 2.155 of Total !runoff Area 8.300 ac Runoff ''Volume 2.199 of Average Runoff [depth 3.18`° is rr STEVENS oto March 4, 2004 ENGINEERS Mr. Jeff Hause River Valley Re ntd s 14210 1 Oth Street North Stillwater, MN 55082 Re: East Oaks Development - Existing Sanitary or Storm Sewer Pipes Our File No. 5046 Dear Mr. Hause: We have evaluated the structural capacity of the exisfing 12' RCP Class 4 sanitary sewer pipe and the existing 36' RCP Class 5 storm sewer pipe that crass the property. Both p i p es are at or exceed the design maximum depth of bury as they currency exist. If fill is added to the site, the pipes must be replaced with a heavier grade pipe. The proposed grading plan requires till to be added to the site therefore requiring the replacement of both pipes with Class 4000D and 5000D RCP depending on the location. In our opinion, any reasonable development on this site will require the replacement of the two pipes. If you have any questions regarding this information please feel free to calf our office at 651 .436.2075. Yours very truly, STEVENS ENGINEERS, INC. Scott A, Ward, P. E. : Eric Johnson - City Administrator Dennis Poster - Bonestroo & Associates Jim DeBenedet. - Stevens Engineers 1555 Livingstone Road - Hudson, W1 54015 715-386-5819 ° 851 -438 -2075 - 300- 822 -7570 - fax: 715-386-5879 - www,stevense.ngineers.com March 5, 2004 STEVENS E N G I N E E R S Mr. Jeff hlause River Dailey Rentals 1421 oth Street north Stillwater, MN 55052 Re: East Oaks Develop Storm Water Management Plan and Pond Alterations Dear Mr. Hause: This letter is a summary report on our findings and reco mendabon on the subject of the storm water pond design fior your proposed amendment to the East oaks PIED. The City of Oak Park Freights requested that we address the quesfion of whether the existing pond will need to be increased to handle the additional hard cover on the site° We have done that and determined that the existing pond must be increased in size, the outlet pipe must be replaced Ah a larger pipe and an outlet structure, but this can be accomplished within the parameters of the site plan as proposed. The revised storm water pond and outlet will meet current design standards for storm water ponds. The design of the existng pond included the total area of the PUD and immediate tributary area. However, the runoff curve numbers did not consider the amount of hard cover proposed for this project. The existng pond has a 21" diameter RCP pipe outlet. This is connected to the ex#sbng 36" storm sewer that runs through the site. Our calculafions and concept design indicate that we can maintain the existing peak rate of discharge to this storm sewer by expanding the pond and by replacing the 21 outlet pipe with a 24" pipe and an oubet control structure. We used Hyd roCAD I' software to model the ru noff and pond routing. The commercial o utlot p rop osed for development is not now routed through the pond. This is shown in our existing condition rout. g schernatce We routed the flows to the existng 36' storm sower for purposes of cornpufing summed hydrographs to compare existing and proposed fi0wse After � develo men the out runoff will be routed through the pond. This is shown in the proposed development condifion routing schematic, The schematics and flow summaries are attached to this letter. J 1 M AM Y DOCUMENTSQEF F HAUS E 03C604.DOC 504 1666 Livingstone Road *Hudson, W1 54016 716- 386W6819 - 436w�075 800- 822 -7670 fax: 715 - 385 -5879 • www.stevensengineers.com We wiii be available to answer your guestons regarding this subject at your nneebng of March .11��. We are available to discuss this with your staff at their conven Sincerely, antes Pa Denedet, P.E. STEVENS ENGINEERS, INC. enc. Pc. Eric Johnson, City Administrator Dennis poster, P,E., City Engineer Mr. Jeff Hause Pag e 2 March 5, 2004 .. .. •. � �. ���. ��....�� I 1, .1„ 11 1 111,1.1,111„ 1,1 11w1�,11,, •�il i. ,,,, „ ......... .. .. . .. . ... IN. 111.11 k „ � 41. ,• 1,,,1,11.1,1 � 11,..111.1... �.. �• 1,111, 1,111• I16 ,.11.111Y1, 1,11,1 ,i1 1.41. 11111 „ 11 , 1 , 1� „.1 �I1. ��,1 .�� ., „111111x,1 , 11 , 1.1 , 1 „ 1 , A 11,�1�1,111� 1.1.. Pl ,���.�.�� •. .1 1,1 4111,1,.1 iii 1,6,111.1611 A, 1, -11 1. 11 ANN ,�,,, ��11,6111 „1 „1 „1, �, 1,16. f��1 „111.1 „1111 ii li���ii 6,� „�,i,�� , ������ , 11,4 „111,,1,.,�11�,161,611i ih1 „111�1,11 .•.1 .��� •..1 „i611,•,lk sting Commercial Outlot. in Pip P Pond 1 2S ) - Y Twinhome Area .1,1.,1,6 ,1,. 1,., ,,, 1, 11, 1, ,16,1 11,11 unn 11111 „1111116,111,1,1,1,11,1,.1 „ 6 11.1.1 �.. 111.•,.It Re ach G� L - D rafnage Di for East O aks E x ist 2004 te �ub�'d Prepared by (err your company name hvrp 3142t3 ---� '' Hydro Al0 1.00 s� 002721 0 1986 Appiled M croaomput�r Systems ,1, 1 11 11 11111116111 I 1 ,11„ 1 1 1, 11 11 p4W„ East teaks Exist 2004 Type 1124 -hr 100 Year Ralnfa &5.90 Prepared by Stevens Engineers - JPD Page 7 �droCADO 7.00 s1n 002721 0 1986 -2003 Applied Microcomputer systems 3151294 9:09,35, AM Time span --5.00 -29.00 hrs, dt=0.05 hrs, 301 poi Runoff by SCS TR--20 method, UH= SCS Reach muting by Stor " Ind +Trans method - Pond routing by Stor -Ind method Su bcatchment 1S: Commercial Ourlot Runoff Area =2°330 ac Runoff t)epth =2.50" Flow Length =750' Tc =9.8 min CN ~70 Ruhoff=9,70 cfs 0.485 of Suhcatchment 2S: Twlnhome Area runoff Area =5.970 ac Runoff Depth- To =10.0 min CN =76 Runoff29.70 ofs 1.514 of Reach 4R: Existing 36 in Pipe Peak Depth =0.82' Max Vet =15.5 fps Inflow =24.44 cfs 1.977 of Dw36.4" nwO.413 L =500.0` Sn0.0500 "r Capac ;=149.1 ofs Outflow -24.28 cfs 1.975 of Pond 3P: Pond 1 Peak Elev=844.58` Storage ®17,596 of Inflovim29.70 cfs 1.514 of 21.0" x 98.0' Culvert 0Utfl cfs 1.493 of Total Runoff Area - 8.300 ac Ru noff Volume 1,999 of Average Runoff Depth 2r89i ti I'll � ���� 1 .. �k k....... k 1 i�����0�. ...... .... ����� �� .11 �i���lail li.o� i ns n, ����� �111114.11...... 1.. 011. n l�n '.... '.. ���.�� � ���� ��� 0. 1 1, 11111111 i�.�� �� 1. 1.... 1� � u.. 1. �. 111 k III I. h ICI, I I.. 1111..1. �. �k 1. �.�..����- 1...1 la,.I,k1 ��u��lno�� 4.1 l.oao 1 k.111 "1 ilk.. �. .. �. ���.61.61 Ilwi����n... �� i. � 1 -1,1 1.i...1111.1 16, k I 1 -1, �l. uillu11,dsn n n l ally.. ,lmna 111.. fia..� I -11. ...n l�n l���' ll�l.��.�. . .... ......i•sl��s d����.n...,l.a.��.��.�l,n�, l.i i.111 l.Is. rlFir'�� �... 1 ...1. � 1 it ' A '•r Commercial Out k ' Sting 3 - n Pipe Pond 1 Twinh Area ^ • 1 e i.ii iii i ..i ii ii.i i i i it .il i � i i i i iii i i i ii ii ,. i•i � .. i iliiil�i. iiii i.iii � AO ..[ Drainage Diagram for East Oaks Nropc�sed 20D4 Ub ,. prw r �uans Engineers,- JPD $� �' Mydro CA T. s1n D ?�1 1 N Apped Ml000mpur 5�ms 1 � „�, 11 � 1...11 � .1..•.111�1� ,111 � �� 1 � � � � 1 .1.1..1.1 � 1..11.. 11 �1• I 1 11 Ilk IIIIIk II.IkIII 1 .lei I k11 li�i lii 1 li 1 1 East oak s P rop osed 2004 Type i► z4-h 100 Year Kara ]1 =5.90" Prepared b Stevens Engine - JPD Page 14 Pr � y iydr oCALO 7.00 s1n 002721 01 986 -2003 Applied Microcomputer i Iputer SVsts i s 3/5120 9 :28:17 AM Time span =5.00 -24.00 hrs, dt =0.03 hrs, 501 points Runoff by SCS TR-20 method, U H=SAS Reach routing by Stor-- ind+Trans method - Pond routing by Stor- nd method Subcatchment 1S,: Commercial OW110t Runoff Area =2.330 ac Runoff Depta3.53" Flow Length =750' Tc =5.2 min CN41 Runoff- cfs 0.686 of Subcatchment 2S; Twinhome Area Runoff Aream5.970 ac Runoff Depth=3.04" To -10.0 min Chi =76 Runoff- cfs 1.514 of Reach 4R: Existing 36 in Piwpe Peak Depth =0.78` max Vel =15.1 fps Inflow - -21.92 ofs 2.156 of D=36.0"' n =0.013 L=5 00.0' S=0.0500 capacity=149.1 4 cfs outllow=21.88 cfs 2.154 of Pon P Pon 3P: and I Peak Elev= 845.44' Storage = 35,301 cf Inflow cfs 2.199 of Outflow- cfs 2.155 of Total Ru noff Area ° 8.300 ac Runo 'Vo 2.199 of Average R unoff De pth