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HomeMy WebLinkAboutDrainage Reports - 09/20/2010 (2)n� NORTHERN ADDRESS: _ PHONE:970.221.4158 WEBS. _ 200 S. College Ave. Suite 100 E N G I N E E R I N G Fort Collins, CO80524 FAX:970.221.4159 www.northemengineering.com September 13, 2010 City of Fort Collins Stormwater Utility 700 Wood Street Fort Collins, Colorado 80521 City of Ft. Collin"rQyAd Plans Approved By Date q-a.o la RE: Addendum to Final Drainage Report — Interchange Business Park Otterbox Warehouse Expansion . Dear Staff: Northern Engineering is pleased to submit this Addendum to the Final Drainage Report for Interchange Business Park dated April 13, 2001. The Otterbox Warehouse Expansion will occur within Lots 10 and-11 of Interchange Business Park. The expansion will consist of the addition of warehouse space to the current Otterbox facility located within Lots 9 and'10 of Interchange Business Park. In addition to construction of the warehouse addition, associated parking space and utilities will be constructed with the expansion. Also, expansion/modification to the existing water quality pond, at the rear of the building, will be constructed. A new water quality pond will be constructed at the northwest corner of the property as well. The expanded/modified pond at the rear of the building will consist of the addition of volume by grading. Also a modified outlet structure, consisting of the addition of a standpipe with water quality holes, will be constructed. The new water quality pond at the northwest corner of the property will be constructed as a standard 40-hour extended detention basin. In conformance with the approved report for Interchange Business Park, water quality enhancement is required. However, detention is not required with the Interchange Business Park development, due to its proximity to the Boxelder Creek major drainageway. The Boxelder Creek 100-year floodplain encroaches the project site and is delineated on the Drainage Exhibit (see back map pocket). FEMA FIRM Panel Number 08069C1003F for Larimer County (LOMR dated 2/22/2010) is referenced in this study, and delineation of floodplain and floodway boundaries shown on the Drainage Exhibit are consistent with the FIRM. The base (100-year) flood elevation in the vicinity of the proposed structure is 4925.00 (City of Fort Collins NGVD-29), 4928.00 (NAVD-88). The finished floor of the proposed structure is at elevation 4929.55 (City of Fort Collins NGVD-29), 4932.55 (NAVD-88), allowing the regulatory flood protection elevation (minimum 1.5-feet above base flood elevation) to be met. All HVAC will also exceed the regulatory flood protection elevation. The proposed structure is proposed to be located outside of the 100-year floodplain boundary by a minimum of 7-inches horizontally, and by a minimum of 3.42-feet vertically. Proposed use of the structure is a warehouse facility. The structure's foundation will be of slab on grade construction; the outer wall of the structure will be supported by a spread footing. The FEMA regulatory half -foot floodway also encroaches the site and is delineated on the Drainage Exhibit. No fill (or any other development/construction activity) shall be allowed within the half -foot floodway. A floodplain use permit is required for each structure and each site construction element (water quality pond, bike path, parking lots, utilities, etc.) in the floodplain.- Additionally, a FEMA elevation certificate must be completed and approved for the structure prior to issuance of Certificate of Occupancy. Per the construction documents accompanying this drainage report, there are no proposed fences located within the floodway. The development will be in compliance with all applicable floodplain regulations per Chapter 10 of City Code. DESCRIPTION ELEVATION ELEVATION FTC NGVD-29) (NAVD-88 FEMA BFE 4925 4928 REGULATORYFLOOD 4926.5 4929.5 PROTECTION ELEVATION LOWEST FLOOR ELEVATION 4929.55 4932.55 FLOODPLAIN SUMMARY TABLE Please see attachments 1 through 4 for all pertinent drainage calculations for the proposed construction: Attachment 1- Developed drainage calculations Attachment 2 - Water quality pond calculations Attachment 3 - Riprap calculations Attachment 4 - Erosion control surety deposit calculations Attachment 5 — Portion of FIRM panel 1003 If you should have any questions as you review this report, please feel free to contact us. Si NG SERVICES, INC. ATTACHMENT 1 DEVELOPED DRAINAGE CALCULATIONS N G Z 0 2 000cfOo OCL0 a d o 1► c EoCD rnaoo U - Q N V m ._�. C u mG1 p Q U T p �j O O M 0 O 0 O Li oo m $ E ° ° O p d O U U 2 N 00 Ui7 M T •°• LL a V LIL U j, C m N O to W v N E y 0 0 0 O Q N O O U U ` M V Cl) a) u N '� m CL N O10 cn W CD N Zcm ' «p ° p C 0 0 O to (�j Ncc c Q Cl a E O rn a rn o o m U o c Q C 10 z m Q c 2 A d rn H o 'U) to T to O LQ to O to to c > y y Coco O 0 N O c O y O m0 0 0 0 0 IL m Q (n m y y d O ° ° 3 a 0 0 V N • i N ° C v N N W a 0 0, e 9 a 0 co c :or�m Y W Q a C y N o0 0 0 CD CO U o� m 0) rn co 0dH 75 a`y0 a c 0 O O to o ` Q y f0M _ U � . N 1 tnm O y m G C 0 0 y m O Q E ° i c L a o �ioo4- Q.y..O(ONM j 't C7 c G t W inY `o o =t W o Q U U X, to U a- N co V F 3 L J C m U �Q 'e O Y A L V G 5, ~ E N N N N y E c Z 0 No o C? c ~ E ¢¢¢¢ z z z z o 17 Q N c0 ¢ > N � m y O O O a O 5 U d y Z y O O e 0 O 0 O 6 0 O y QJ L cm� O O O O C Z J =�¢¢a W C� Z ~Eozzz 0 LL.N O p p a N N 0 O 0 O 0 O IL i W ` z y CL ooOO 0 c 00 o ` J r y co O v C �E V �Lo4ui N th ftft `o_ m 2 m 3 ai^ooNN W !L O d O N N c J C :i W N CM� C.1 0 N 0 m 0 N Oi 0 V c6 II p U Qv° a°ri Cll7. E * c gm iLL LLC c �LL S E `m NF+ y�NMa C1 3 Luli. 3 3 m m y LL ."i A 5 3 o F •- t9 v W ii 10 y C <n C U.0 oa 0 m b `ma e} 5 0 0 0 ooF- v EoNviui y d E_ Z ~ Oo o c ~ E Q z Q z Q z Q z 0 U N a0 Q i `Q d A m Ix ,o a o 0 0 o o OC � V A O d CL 0 0 0 0 0° 0 0 0 0 y J `Q 2 C W J Z E�000 Eozzz V 0 - c NLOa0m o���n000 c o 0 W "> y z CL m000 0 0 0 0 O Ix y J J //� COJ OR ~ E O N N N Cl) Q O W IL O y /� r m J > Q Ol x' a �•OjLn 1� W Ix �� m o �yUu J o W o r� 0 0 J C .Uf, N N ;� m 0 o _ ° d W Q L E o F U> 3 o FL FL o IL 1 �LL � E 0' d� m• -NMv U3 LOULL 3 3 m y LL l0 Q ° 3 o F= (� y FL O N coo + �A V py C 0 r" O. m o o 0O�NMa a a 0 F C9 F= F- c>> w o o tll G I co M - 0 (Y OV O to 00 - 3 w� O � LO N N 0 0 7 'A O Cp o U `- IL V CD 1 v+ N 00 Q O V ad+ T m d R w o Lp LO LO Ln C t O 0) 0) O 0) 0) C) c s aw�tnLO L Lc) Lf) y C 00 N 00 N 00 N 00 N O C U LL 00 o O M O 0 O 0 O (U 1 o l0 LO U) N - - V M N 0) m O O O O H O O _ G � Lon In tli l!i OG 2 O � O LA O O V a £ LO LO 07 t O W " Q O y `1 c- V (O CO d N YO 00 J R o 0 0 0 luj a W tl! NN CO c} l0 m � C da c ATTACHMENT 2 WATER QUALITY POND CALCULATIONS WATER QUALITY POND DESIGN CALCULATIONS_ Southwest Water Quality Pond - POND A Project: 236-002 By: ATC Date: 8.10.10 STORAGE & OUTLET WORKS: BASIN AREA = 0.910 <— INPUT from impervious calcs BASIN IMPERVIOUSNESS PERCENT = 95.00 <-- INPUT from impervious calcs BASIN IMPERVIOUSNESS RATIO = 0.9500 <-- CALCULATED WQCV (watershed inches) = 0.447 <— CALCULATED from Figure EDB-2 WQCV (ac-ft) = 0.041 <-- CALCULATED from UDFCD DCM V.3 Section 6.5 WQ Depth (ft) = 2.500 <-- INPUT from stage -storage table AREA REQUIRED PER ROW,.a (In) = 0.077 <-- CALCULATED from Figure EDB-3 CIRCULAR PERFORA' dia (in) = 5/16 <— INPUT from Figure 5 n = 1 <-- INPUT from Figure 5 t (in) = 1 /4 <-- INPUT from Figure 5 number of rows = 4 <-- CALCULATED from WQ Depth and row spacing I Q A Q 00 Qr t� N � V Rj T 11 J O ^ U i +' N M M m0 N n r\ M LO N d N d to st to m0 N 0 000 M CO N a• N Z O Q � O O N ^ M O N N � (D r 00 00 — 00 00 N O � o U 1— V N N M u) to 00 M c0 O N d N 0o N M M v H J ^ > Q n 00 tD 00 M r- o o M O o Ln 0 o r� 00 � M N 00 0) Z \ N o N (0 0) 0 (� Z ^ ON M MO (D 00 _ 0) Z � N N M M M LEI Q O ^ J M W > a.-� .� O a0 - 00 00 M 0 O 00 0) 0) M Ln cD 't M 0 cD n c0 O 0 �t qt 0 M Q -� Q 0 O 0 I� � ( M M N 00 0 0 N 00 N O) 00 I� 00 00 N 00 00 OJ o M 4 V � N > {— U N M U') (0 00 M CD O N ONO M Q O `� W f— _ Q OW> �-- Q 00 � ON o O M N O^ (D O M M V) \ Z r` M oN 0 (D O w (V 0) M 00 CO M Q1 (D M OM OV M r` M W (, M (D 00 N N � M N M Q Z U — ~ (n f— ^ 0 O 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 w= N N N N N N N N N N N N 0 N 0 N 0 N 0 N 0 N Z O O O O O O O O O O O O O O O O O ^ "- 0 (D 00 to N N N (0 M m N 00 O m N N M W 0 N N r\ r. (V � N O M M Uj 0 (0 tt N 0 O N M 00 Q co M N N M O N �t co 00 O N to N N N 0 O O O O O 0 o O O O O O O O O O 0 i O o o O O O O o O o O o O o O O O O co 00 O N � W M O N � cO M O N ., O 00 O W -i O N O N N N N N N N N N N N N N N N N M N M N ri N M N M N 4 N W 0) O) 0) 0) . 0) 0) 0) 0 O) 0) O) 0) 0) O 0) 0) 0) 0) .4 d7 .4 -47 d7 .4 47 q47 .4 .4 '47 .4 d7 q! (WATER QUALITY POND DESIGN CALCULATIONS Southeast Water Qualitv Pond - POND B ATC ..aI TLET WORKS: BASIN AREA = 0.830 <--INPUT from impervious talcs BASIN IMPERVIOUSNESS PERCENT = 89.00 <- INPUT from impervious calcs BASIN IMPERVIOUSNESS RATIO = 0.8900 <— CALCULATED WQCV (watershed inches) = 0.393 <— CALCULATED from Figure EDB-2 WQCV (ac-ft) = 0.033 <--CALCULATED from UDFCD DCM V.3 Section 6.5 WQ Depth (ft) = 2.000 <— INPUT from stage -storage table AREA REQUIRED PER ROW, a (in2) = 0.083 <— CALCULATED from Figure EDB-3 CIRCULAR PERFORATION SIZING: dia (in) = 3/8 <— INPUT from Figure 5 n = 1 <— INPUT from Figure 5 It (in) = 1/4 <— INPUT from Figure 5 number of rows = 6 <-- CALCULATED from WO Depth and row spacing J U > + O w cD N 4 M M CD CD c0 � of O Z J 0 Q O O rn ' a? °) � o Q) N O O U) N ri U M I" O M 0 � J � U O 4 Q 00 rn o O M M o N oo 00 z O \ Z COLn O . N O N N N M Z � LiJ p OJ -J m Z> ++ W "- O O = 00 r op O N M r- N M CD Q O cD M rn N O cD (D > f— U �- M M O CN c0 W Q O U ~ Q m � J O Z Q + W> `� Q O N Ln a7 a0 00 N M Ln O N 00 m M r- (' Z cD M I� N a7 W U Q Z .- N N N M Ucn — ~ = ~ Q O O O O O O O O O O O O O O O O O O O O W Z O O O O O O O O O O Q+ +- M cD M O M O N N O M N O M W ON r- M M — Q raj) M c0 m 0 (D M 00 O O O O O O O O O O O > O O O N O O cD O 00 O O O N O � O O O 00 O. O W N N N N N M M M M M 4 —� W N rn N 0) N rn N rn (N 0) N rn N rn N rn_ N rn N rn N rn 1*7 \ 13 , NA PROJECT JOB NO. CLIENT CALCULATIONS FOR C MADE BY DATE SHEET C CHECKED BY. FORT COLLINS, COLORADO 80521 i14 L t.1L O i . -04 L/,Q ..4-n c) . S v A{r. DIeI F�c.E 47 I --- z I _3— � � •� _�_5 I oz,5o 1 �� I I I f I Y✓�// I!\'fir-. - -__ C2iFI�E Z {Zi '.�(ODfOf 61l�/ O j,'� 6`�.�.�8 I I 4:07-4L FLO' 00(o en �.r IFS � � o �- �iP� LL k)►--P��� �'L n�q 4r�1Y 553) Worksheet Worksheet for Circular Channel Project Description Worksheet 4-INCH PVC CA Flow Element Circular Channe Method Manning's Forme Solve For Discharge Input Data Mannings Coeffic 0.013 Slope 005000 ft/ft Depth 0.33 ft Diameter 4 in Results Discharge 0.14 cfs Flow Area 0.1 ft' Wetted Perime 1.03 It Top Width 0.02 It Critical Depth 0.21 It Percent Full 99.9 % Critical Slope 0.010176 ft/ft Velocity 1.56 ft/s Velocity Head 0.04 ft Specific Energ: 0.37 ft Froude Numbe 0.14 - Maximum Disc 0.14 cfs Discharge Full 0.13 cfs Slope Full 0.005137 ft/ft Flow Type 3ubcritical q Project Engineer: Northern Engineering Services c:\haestad\fmw\dummay.fm2 Northern Engineering Services FlowMaster v6.1 [614n] 08/10/10 03:40-13 PM ©Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1 ATTACHMENT 3 RIPRAP CALCULATIONS % ) } , $!!`£ ! i r• ■mc/ ��k� \ / vm ); � ƒ« 2 LU )k\M IL , o, « 2 y §,j/ «ƒ§) 2 ; \ K � w Q < _ < � ui * / /4� 0 2;gym 0- a 0. o !! _ - S 2 g e z � § w}}« « $ k Co =! ƒJ!® ■ \ ` \�kF z §[_ e\_ ];j; R� U) `j~ /4< )�)� �cm ATTACHMENT 4 EROSION CONTROL SURETY CALCULATION Erosion Control Cost Estimate Project Number: 236-002 Location: Fort Collins, CO Date: July 13, 2010 Total Disturbed Acres: 1.9 Estimated Unit Total EROSION CONTROL MEASURE Units Quantity Price Price Wattle Inlet Filters each 3 $100.00 $300.00 Silt Fencing L.F. 325 $1.50 $487.50 Wattle Dikes each 2 $125.00 $250.00 Vehicle Tracking Control Pads each 1 $300.00 $300.00 TOTAL = $1,337.50 AMOUNT OF SECURITY = 1.5 x $1,337.50 = TOTAL = $2,006.25 -OR- COST TO VEGETATE: TOTAL ACRES x ($1000/acre) x 1.5 = TOTAL = $2,850.00 (WHICHEVER IS GREATER) REQUIRED AMOUNT OF SECURITY = $2,850.00 ATTACHMENT 5 PORTION OF FIRM PANEL 1003 E 1455000 FT ZONE AE 4 BR. < o". i a z ZONE AE (EL 4924) ZONE AE . B"elder Creek 1-25 Split LARIMER COUNT' i IN'CORPORATED ARE, "Olaf ZCtiE AE .. S LARIMER ZONE AE Z COUNTY 3 \ A AD 4� AN 494 4950 RAUIEL c RT PONOEROSA DR ••r NILDW [AWE 4945 QR 4947 HOC AL 8 F v aacLE a 4944W 11 ° Baker Loki !! urlArr Gmmk s a RE\/ISED Ift,N�R AF' AREA MULBERRY STREET ' [ ANNUAL CMANCE FLOOD DISCHARGE ONTAITAINED IN CULVERT N 4 493�3< 4 4 i 1 �� 2 ZO,SlE AO PALAMINO LN LARIMER COUNTS' UNINCORPORATED AREAS V 4 81 8 DENROSE 49 4-,-[ 3, tt DEATH B 1T 1nexS 090101 e BR5 ./ A P SO"Ih BRENTON ORNE P.. - Z NE AE A l�li•� Jay oANOE cT /u •i-"� AE Legend _1%annual chance .APO p910 ♦ °- 4932 p2 (100-Year) FIOOEplain "I +� I_1%annual chance Business -/�� v Bu inc s ° (1 00-Year) Floodway r�- •,' -.. Park Wesl ' par Mi dla Q 0.2% annual chance qO suncHAee m DRNE (500-Year) Flootlplain 2 CSPIRIi DRNE u MAP SCALE V = 500- souws DRNE PROJECT SITE /„zoNE FEET AO , 50 0 150 I Pie .y 2 LARIMER COUNTY 15 CITY OF FORT COLLINS P I r CITY OF FORT COLLINS �j� "01a} / ZONE AE .t PANEL 1003E FIRM FLOOD INSURANCE RATE NAP LARIMER COUNTY, COLORADO AND INCORPORATED AREAS I PANEL 1003 OF 1420 ISEE EUY ,MF ., I'.. I., IAYaUII :W. IBS: f.(aCM90'^ tlYl9E3 ANEL 51/E:IE EVISED TO EFLECT LOMR :FECTIVE: February 22, 2010 .... NAP RUNIER OIONC7001F -� `. `-„P.• &TWnYE DATE DECBlER1E,M011 FW" Eneeauey M.A.P—RI AaeRn