Loading...
HomeMy WebLinkAboutDrainage Reports - 12/05/2016W MEMORANDUM To: Dan Mogen, EI, CFM From: Tim Halopoff, PE Date: December 1, 2016 Subject: 620 S. Sherwood Street- Drainage Analysis J•R ENGINEERING A Westrian Company City of F Collins Ap ro ed Plans Approved b Date; `2/s /Zotly JR Engineering, LLC has completed a storm drainage evaluation for the 620 S Sherwood Street project. The following is a summary of the findings and determinations made while performing an analysis of the proposed 620 S. Sherwood Street project in order to determine the site's drainage patterns, requirements, and conclusions. 620 S. Sherwood Street previously had a 1 story house that took up approximately .04 acres in addition to the existing duplex as can be seen in Exhibit A attached to this memo. Exhibit A also contains the proposed site layout. With the original house included, the composite imperviousness on site amounted to approximately 52%. In 2001, the house was demolished, but the duplex remained, leaving the lot in its current state; which will now be referred to as existing condition. Exhibit B shows the square footages of the impervious and pervious areas that will exist following construction of the new house. Due to the fact that the proposed new impervious area is only 2,882.1sf, significantly less than 5,000 square feet, no detention, water quality, or LID's are required. Exhibit C shows the results of the impervious area calculations for the site in its existing and proposed states. The composite percent imperviousness of the site will increase from approximately 36% to 68% once all improvements are constructed, which is not atypical for a residential lot. Additionally, it should be noted that the proposed composite imperviousness is only 14% higher than what it was in the sites original condition with the original house and duplex. Since it was determined that the additional impervious surface that is being added to the current site condition is less than the 5,000 square foot threshold, we then studied the flow path of storm water on and around the site. Currently, storm water conveyed by the subject sites includes a small portion of land on the north part of the adjacent property to the south and that which falls directly on the lot. The existing flow path for these waters is a sheet flow onto the lot north of our project. Thus, our design includes gathering the existing flows and safely conveying them to the existing Sherwood Street curb line via two concrete trickle pans and two curb chases. The use of gradually sloped trickle pans improves the drainage situation for all the lots involved. Finally, this project will have no adverse drainage effects on neighboring properties, if built per approved plans. Sincerely, Timothy J. Halopoff, PE 07200 South Alton Way. Suite C400 ❑ 130 East Kiowa Street, Suite 400 M2900 South College Avenue, Suite 31) Centennial.. C0801 l2 Colorado Springs, C080903 Fort Collins. C080525 303-740-9393 • Fax 303-921-7320 719-593-2593 • Fax 303-921-7320 970-491-9888 • Fax 303-921-7320 w Exhibit A 07200 South Alton Way, Suite C400 0130 East Kiowa Street, Suite 400 02900 South College Avenue, Suite 3D Centennial, CON112 Colorado Springs, CO80903 Fort Collins, CO80525 303-740-9393 • Fax 303-921-7320 719-593-2593 • Fax 303-921-7320 970-491-9888 • Fax 303-921-7320 • � I I � I I I I 21 oRY JJ W WI I I I �IIIf' SERVICEI (EXIST) h 0 3/4- WATER I SERVICE I(EXISP 'S C RB SRO; II In I f0.0' Jj I 20' I EXISTING DRIVEWAJ I I SPHALT PATCH 30 +/ w lII �I I I t- V) I I r I I EXHIBIT A 10 5 0 10 20 SCALES P = 10' LOT 21 1' k HOUSE NCB I; _ SINGLE FAMILY RES. EXISTING TREE. J CANOPY NEV 6' r�------------ EXISTING TREE . -L _ _ _ _ - CANOPY �-'l LOT 22'` I % AREA=9436.E SF..` � I I 1 L-t •; I 14EXISTING I 1-STORY —___—_ —.� HOUSE I r TREES TO REMAIN � NiATER METER , �✓ I I I xIMULt ♦1' 3/4" WATER SERVICE—, T G 4" SANITARY SEWER SERVICE a r - --- r J LOTS 23 & 24 SHERWOOD GREENS �. CONDOMINIUMS NCB 1 I i WEST MYRTLE STREET zo' Q 10o O J J O \ O J J © O F — Q H < t W W O O 1i W O Qr' w� J� in Fn 6) O © 75 4 Z W o: © 0 © © Z� 0 W 0 sly N O m 0 O LLJ O it ®� CONDOMINIUMS fn O ; ®L---- O 0 0 20' o O 3 x K W N C soRORrSORORITYsoSORORITY HOUSE HOUSE Z) O V) O © O O 100' $ WEST LAUREL STREET _ o LOCATION MAP 1"=]00' 19' 6'a6' - ELECTRIC�� - ASSMENT I . I ELECTRIC r -I PEDESTAL I II I II I II I I I II I II I I I City of Fort Collins, Colorado UTILITY PLAN APPROVAL APPROVED: necfd of Enginminq oafs CHECKED BY:fpp,, roe1pC_ Dot. CHECKED BY: f" Sto-.1- utany Dote CHECKED BY. Dote CHECKED BY: Dote CHECKED BY: Date own I I I 1 I II R •m�■I■E��� il■I ■■■� END OF NEW PAVEMENT I TYPE 13 GRATED INLET GRATE E1=5001.00 I i INV IN(W)=4998.89 I EX INV WT(N):4998.89 I NEW PAVEMENT VICINITY MAP N TS j 7.97 LOT 11 I � NCB I i SINGLE FAMILY RES I � 1 i I I 7.8T — — I I LLJ EXISTING I J I 1 PAVEMENT I I J I 1 I Q I II I I -0 I II N I II I 1 I E705T 2' CONC. PAN I I I I i l o z I I II C 20' � c $ VARIES SEE PLAN 2' ARIES SEE PLAN � W 15AMEO; o. i 8' lleCl( LXINC. PAN ALLEY SECTION EoacWc Nonni O I\ IC, I IIn C I m Z J 0 LAND USE CHART m a U LOT AREA = 9.437 SF = 0.22 ACRES (n TOTAL FLOOR AREA = 5,173 SF F; fr~-t W FLOOR AREA RATIO = 0.55 N .J-. EXISTING ZONING NCB 0 TOTAL NUMBER OF DWELLING UNITS 3 C3 Z _ TYPE OF DWELLING UNITS HOUSE/DU-PLEX DENSITY 13.64 DU/ACRE O 94 Z TOTAL BEDROOMS PER DWELLING UNIT 2 FOR DUPLEX 3 ZQ [Y MAXIMUM BUILDING HEIGHT 21' 3 W II — PARKING SPACES REWIRED 4 = Q (n PARKING SPACES PROVIDED 4 V) J EL E SQ- FT. p BUILDING COVERAGE 35% 3.301 (n W DRIVEWAY AND PARKING COVERAGE 7% 684 F- SIDEWALK COVERAGE OS 0 0 y PUBLIC STREET RIGHT-OF-WAY OE 0 N OPEN SPACE AND/OR LANDSCAPED AREA 58% 5,452 (O 'ACTIVE RECREATIONAL USE' AREA OS 0 TOTALS 100% 9.437 SHEET 2 OF 4 JOB N0. REV. )047.00 0 C-3 1601 µ�' �J �i CdIw, C0605111I3n I I I I I I I I I I I I I I I I I 1 i j l I I I II d �• I I I II I EXIST DRIVE APPROACH I I II CHANNEL jL I I Iln CURB CUT &MATCH CURB I1 F -EXIST C&G (SEE DETAIL BELOW) l� FL -' I V I I FL -EXIST C&G ,= I SW CHASE • o I INSTALL SANITARY SEWER 4" TEE REPLACE JR SADDLE TAP PER SANITARY EXIST SIDEWALK H ; I SERWCE DETAIL (BELOW). EXTEND I I EXIST FENCE it 11 4" SERVICE TO HOUSE AT 2% MIN I^ 3 (TO BE REMOVED) II I rr-� - --- - FALLx8 ' UT TO EXTENDWACROSS II (i' FULL 'MOTH OF ' �/ �' ' �' / i . �. / �i. 1111� EXIST SHERWOOD'''�'1� .._.1� LANDSCAPE REMOVE EXIST 4" SANITARY.I� N,- II ABANDON TO THE MAIN PER CITY I EX 3-rrFCRE. OF FORT COLUNS REOUIREMENTS. I WATER METER &VAULT EXIST 4" SANITARY (REFERENCED (TO REMAIN)FROM 620 S. SHERWOODiST.-BLDG. B, SHEET 2 CIRCA'96) W-----W-4.1'/CONTRACTOR TO VERIFY LOCATION1= I PRIOR TO SAWCUT AND REMOVAL EXIST CURB & GUTTER DRIVE APPROACH(TO BE REPLACEDSHER{41700STREET L S RIVE A ROW) I l 1 EX 3/4'EwsT DRIVE APPROACH °3WATER METER & VAULT FORDUPLE% EXIST 4" SANITARY (TO REMAIN)1.8'SERVICE FORDUPLEX a (CONTRACTOR TO _(TO REMAIN) I z VERIFY) 11 I I I EXIST CONC II APPROACH II I I D: I DRIVE APPROACH (TO BE REMOVED) II I _y k'3 (TO BE REPLACED) I 11 II I ml 31 I 1 100' ROW w 1 x l 0 3 I DISCLAIMER STATEMENT. NOTES. THESE PLANS HAVE BEEN RENEWED BY THE LOCAL ENTITY FOR CONCEPT ONLY. THE REVIEW DOES NOT IMPLY RESPONSIBILITY BY THE REVIEWING DEPARTMENT, THE LOCAL ENTITY ENGINEER, OR THE LOCAL ENTITY FOR ACCURACY AND CORRECTNESS OF THE CALCULATIONS. FURTHERMORE, THE REVIEW DOES NOT IMPLY THAT QUANTITIES OF ITEMS ON THE PLANS ARE THE FINAL QUANTITIES REQUIRED. THE REVIEW SHALL NOT BE CONSTRUED IN ANY REASON AS ACCEPTANCE OF FINANCIAL RESPONSIBILITY BY THE LOCAL ENTITY FOR ADDITIONAL QUANTITIES OF ITEMS SHOWN THAT MAY BE REWIRED DURING THE CONSTRUCTION PHASE. 1 1 0.75' 1 0.75' /2" — EXHIBIT A EXIST BUILDING L--------T--J II O EXIST TREE EXIST FENCE DRIP LINE FL-18" CONC DRAIN PAN I N8951'OB"E 190.09' LANDSCAPE - 16' 7' SETBACK — - — — STEEL HEADI SETBACK LANDSCAPE _ (TYP) 50' SITTING STONE RETAINING WAL S' //^^vv LANDSCAPE ODVD �` BBQ COURT YARD pDRGH 4" SAN. SERVICE 2 STORY BUILDING .I GRID PATIO AREA (2.0$ MIN FALL (COMPACTED TO MAIN) Sx4' CONIC n CRUSHER FINES STEPS - 4 RISERS LANDING - ) I _ 4' CONIC REQUIRED STEPS - 3 RISERS 1 -SIDEWALK'S -- 50• REQUIRED 30 BBO GRILL 3/4" ATER SERVICE EXIST TREES 1 (TO REMAIN) (CONNECT TO EXIST AT METER) � 2' SW CH SE C WHf FI STOP iHIYP 4.5' w- YP) . 20 20" 85' 85' // S BIKE RACK S i 1 0 8.5' / u (12 BIKES) 3 �RIVER "•.: tl) - � a COBBLL ASPHALT- MULCH - - - - W - - - - W Al WHI-h SIItIF'IhG SAN. i 1 .�: --{TYASPF ALT� - - - - - LT-P) I (TO BE REMOVED) I L ------ T 24" k _ 3 1 FL CONCH DRAT DRAIN PAN EXIST SHRUBS &TREES (TO BE REMOVED) ro— 0— F J EXIST BUILDING Z i 1. GENERAL CONSTRUCTION NOTES f1 THROUGH 18, 20 THROUGH 39, AND 42 THROUGH 46 AS LISTED IN APPENDIX E-1 OF THE LARIMER COUNTY URBAN AREA STREET STANDARDS (LCUASS) SHALL APPLY AND BE FOLLOWED FOR THIS PROJECT. 2. EXISTING WATER AND SEWER SERVICE LOCATIONS TO BE FIELD VERIFIED PRIOR TO CONSTRUCTION. 3. THE ENGINEER WHO HAS PREPARED THESE PLANS, BY EXECUTION Al SEAL HEREOF, DOES HEREBY AFFIRM RESPONSIBILITY TO THE LOCAL ENTITY, AS BENEFICIARY OF SAID ENGINEER'S WORK, FOR ANY ERRORS AND OMISSIONS CONTAINED IN THESE PLANS, AND APPROVAL OF THESE PLANS BY THE LOCAL ENTITY ENGINEER SHALL NOT REUEVE THE ENGINEER WHO HAS PREPARED THESE PLANS OF ALL SUCH RESPONSIBILITY. FURTHER, TO THE EXTENT PERMITTED BY LAW, THE ENGINEER HEREBY AGREES TO HOLD HARMLESS AND INDEMNIFY THE LOCAL ENTITY, AND ITS OFFICERS AND EMPLOYEES, FROM AND AGAINST ALL LIABILITIES, CLAIMS, AND DEMANDS WHICH MAY ARISE FROM ANY ERRORS AND OMISSIONS CONTAINED IN THESE PLANS. 4. DAMAGED CURB, GUTTER AND SIDEWALK EXISTING PRIOR TO CONSTRUCTION, AS WELL AS STREETS, SIDEWALKS, CURBS AND GUTTERS, DESTROYED, DAMAGED OR REMOVED DUE TO CONSTRUCTION OF THIS PROJECT, SHALL BE REPLACED OR RESTORED IN LIKE KIND AT THE DEVELOPER'S EXPENSE PRIOR TO THE ACCEPTANCE OF COMPLETED IMPROVEMENTS Al PRIOR TO THE ISSUANCE OF THE FIRST CERTIFICATE OF OCCUPANCY. THE LIMITS OF THE REPAIRS WILL BE IDENTIFIED IN THE FIELD BY THE CITY ENGINEERING INSPECTOR PRIOR TO AND OVER THE COURSE OF THE PROJECT AND WALL NOT BE SHOWN ON THE PLANS. 5. LIMITS OF STREET CUT ARE APPROXIMATE. FINAL LIMITS ARE TO BE DETERMINED BY THE CITY INSPECTOR. ALL REPAIRS TO BE IN ACCORDANCE WITH CITY STREET REPAIR STANDARDS. _'KLE PAN A— _ BACK OF CU,IB VUVAWES 1L'"ORIl555CRLWjO.C. CCROdIIINNTTHHILW 5�S EDGE OF STREET n1 I1 nW� KATE _--- 3 (TYP.) EXPAl MATERULL _ 7 WI STEEL SECTION A -A f0 tB - B} SWCW'ALK r il•GALV. S'fffLPIATE r• .%'GACI AN'. DETAIL 1 .1 4" '.I _ z 3 ND WA b•ON • OF tC Cj s.oes wAx SECTION B-B f� icl 12"R ITR L, A EIC TE MAT E ss SCREW y� EETT J 3'-3" 3-3" 1OF B O.C. WITn COUNTERSUNK MEAD a,�, 3' OF➢RESSFD FLASH WITH PLATE raHP PLAN O.[. -- Opu• AL GA GLE e3 REBAR 4 ° ANCHOR 18 O.C. A4l3Y o.0 DETAIL 1 SECTION C-C ;UREI & GUTTER AND DETACHED OU'= MOTE: 1. NOT ALL SEMCE UNES WERE ATTACHED TO NEW KALN US­-BEN- 2 "TAMNG DNLL 3LT . CNNEON MADEMA EE SADDLETAPW/GASKETS&S LBAI,DEDTO SANITARY SERVICE DETAIL SCALE: NTS EXIST TREE EXIST FENCE DRIP UNE I � I I LOT 22 1 I IF AREA 9511.1 SF 1 L — — — — — — — — — — I I I I - I I I I J � III I I I EXIST PARKING STALLS c EXIST BUILDING 1 i I I I II i I i III I I L- - - - - - - - - - - II Q 24" 6' _ - -- - _-- ---X— I I 13 _ x EXIST EE DRIP LINE I — — — 20' ALLEY I II I MULBERRY ST P��,E I I I I I F` I MYRTLE ST LAUREL ST SITE CSU CAMPUS z N Zw NW < mot wlnswz -! - Z FZyKwWwmO I�m����OU3F jK �l�(/I�LJO'FN FNm.Z. C waawa zvl� W Q �0Go Go OJ of 5; 5;0 o ��>oHtO, QO O ZU I jZQY�O w < VwZUO� a w Z)Ir D 6 > J 7 �Z EnN N U z ►y RL 'T 5 z3 ZEE X X \ x II DO O VICINITY MAP w J < SCU1 N < ALE: 1'-300' j � • W W 10 5 0 10 20 KRoW Whal'S below. x ORIGINAL SCALE: 1" = 10' Call before you ENGINEER'S STATEMENT o HEREBY AFFIRM THAT THESE FINAL CONSTRUCTION PLANS WERE City of Fort Collins, Colorado UTILITY PLAN APPROVAL O PREPARED UNDER MY DIRECT SUPERVISION, IN ACCORDANCE WITH 3i ALL APPUCABLE CITY OF FORT COLLINS AND STATE OF COLORADO APPROVED: W' STANDARDS AND STATUTES, RESPECTIVELY; AND THAT I AM FULLY City 1i One LLI RESPONSIBLE FOR THE ACCURACY OF ALL DESIGN, REVISIONS, AND CHECKED BY. _ RECORD CONDITIONS THAT I HAVE NOTED ON THE Water&WNNmwercrIJl One o�Pp sCNqICHECKED BY: StommWaa Ull Ell `po'a CHECKED BY: N 37953 Pub&Re°t d- IA.e CO CHECKED BY: TIMOTHY JAMES HALOPOFF, P.E. S:{,,,, �� Tr.B Fs�,«r Dale COLORADO NO, 37953 S-ONAI, E� CHECKED BY: F,Lwemv,ental PhtN,er Date FOR AND ON BEHALF OF JR ENGINEERING, L-C. SHEET 1 OF 2 CHECKED BY: Date JOB No. 3973800 \I Exhibit B 07200 South Alton Way, Suite C400 0130 East Kiowa Street, Suite 400 192900 South College Avenue, Suite 3D Centennial, CO80112 Colorado Springs, CO80903 Fort Collins, CO80525 303-740-9393 • Fax 303-921-7320 719-593-2593 • Fax 303-921-7320 970-491-9888 9 Fax 303-921-7320 Date: 12/1/2016 Location: Fort Collins Project Name: 620 S. Sherwood Street Project No.: 3973800.00 Calculated By: AJH Additional Imperviousness Area Designation Area (sf) Additional Building 834.35 Concrete Walks 125.69 Concrete Pans 621.44 Asphalt Parking 1312.34 Total 2893.82 Additional Perviousness Area Patio (Crusher Fines) 987.21 Landscape Area 1640.17 Total 2627.38 Existing Site Imperviousness Area Duplex 1780.8 Concrete Walks 295.46 Parking 1101.28 Total 3177.54 Existing Perviousness Area Landscape Area 812.36 Total 812.36 Total Addition 5521.2 Total site 9511.1 qw Exhibit C 07200 South Alton Way, Suite C400 0130 East Kiowa Street, Suite 400 02900 South College Avenue, Suite 3D Centennial, CO80112 Colorado Springs, CO80903 Fort Collins, CO80525 303-740-9393 • Fax 303-921-7320 719-593-2593 9 Fax 303-921-7320 970-491-9888 • Fax 303-921-7320 N Z O H g D V J Q u N D 0 W a Z w V LLI a W H O a O u v C E O O m m A t E ri V 00 ° H v u O ID 00 n I� 3 �o 01 a m E 0 N 0 o o •-y o — 3 r� o v C 01 L V d Q N O O O a° G o 0 E � a v o m 0 0 t to M 'm E 3 — l7 c 3 m � M o 0 O 0 a 0 a o 0 3° Oq E � 3 z° y a r, o0 00 a o 0 E � � 0 a�i E C 3 — a £ V n M 0 a d a o 0 a E 0 o o 0 v a V ti O N N O O O O H om C Q m ¢ t o o 0 YO m O a o0 3 a E o 0 0 0 0 a c m N o O 0 N d O O L Q J U 0 G o 0 E v a 0 0 v o v t 0 O 0 o 'a E N 3 — l7 u ti O 3 v o O ° Q 0 a 0 0 E ^ c 0 0 c ° -a. w o 0 V o � 00 L00 O N 'm E 'T X 3 w ° = o V 00 cc o0 a 0 a E o 0 u 0 t a O O ^ eo o C 3 — v £ v o o M 0 a o 0 ti o o o o a Q u d o N F m ¢ C F G IC 00 a K W O