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HomeMy WebLinkAboutSGM Engineering www.sgm-inc.com GLENWOOD SPRINGS 118 West Sixth St, Suite 200 | Glenwood Springs, CO 81601 | 970.945.1004 Page | 1 May 24, 2024 Mr. Dave Reynolds, Town Administrator Garfield County Community Development 108 8th Street, Suite 401 Glenwood Springs, Colorado 81601 RE: Grand Hogback Ranches, Lots 17 and 18 Review of Drainage Report and Civil Plans Final Technical Review Approval Dear Dave, The purpose of this letter is to provide our technical concurrence per our review of data prepared by High Country Engineering for the Drainage Report and Civil Plans in support of the watershed permit application and the Access permit application to the Town of New Castle. We provided a number of comments and concerns in our letter of May 24, 2024 by which the applicant and his engineer have addressed to our satisfaction. You will find attached the following information: a. Construction Drawings for Tract 17 & 18 – Final Plans dated 8-23-24 as prepared by High Country Engineering b. The 8-8-2024 Drainage Report prepared by High Country Engineering c. The email from Tom Scott to myself regarding the existing 30” culvert capacity d. The email from Tom Scott to myself regarding the existing 24” culvert capacity From the Town’s standpoint, we recommend issuance of the Watershed Permit as well as the Access Permit for this project. As well, we would recommend forwarding this letter to the County Planning Department indicating our concurrence with the project unless other staff members have any additional issues that need to be communicated to and addressed by the applicant. Upon receipt and review of this letter if you have any questions, please don’t hesitate to contact me. Respectfully, SGM Jefferey S. Simonson, PE Principal/Town Engineer CR 335 COLORADO RI V E R R O A D 1 inch = ft. (IN U.S. SURVEY FEET) GRAPHIC SCALE 0030 15 30 60 120 30 BY NO . DA T E BY PROJECT NO. OR 5 3 4 - 0 6 7 0 0 I N M E T R O D E N V E R UN D E R G R O U N D M E M B E R U T I L I T I E S EX C A V A T E F O R T H E M A R K I N G O F BE F O R E Y O U D I G , G R A D E , O R CA L L 2 - B U S I N E S S D A Y S I N A D V A N C E 1- 8 0 0 - 9 2 2 - 1 9 8 7 CE N T E R O F C O L O R A D O CA L L U T I L I T Y N O T I F I C A T I O N RE V I S I O N HI G H C O U N T R Y E N G I N E E R I N G , I N C . PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 - F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m dr a w n b y : ch e c k e d b y : da t e : fi l e : 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , GL E N W O O D S P R I N G S , C O 8 1 6 0 1 SHEET NUMBER 2231025.00 C 1 BE L O D I C R E E K R A N C H , L L C GA R F I E L D C O U N T Y , C O L O . EX I S T I N G C O N D I T I O N S M A P TR A C T S 1 7 A N D 1 8 GR A N D H O G B A C K R A N C H E S HC E HC E AU G , 2 0 2 4 EX - 0 1 ORF R EV I E W CR 335 25943.5725943.570.000.00 0.000.00 56 0 0 55 9 5 559 0 56 0 5 5610 5615 5615 5615 5610 5610 5585 5 6 3 5 5 6 3 6 5 6 2 5 5 6 3 0 5615 55 9 9 5 6 0 5 5600 5595 5590 55 9 0 55 9 5 56 0 0 56 0 5 5595 5600 5605 5600 5605 5605 5610 563 6 563 75635 5616 5620 5625 5630 5640 5620 5625 5630 5635 5640 5645 5645 5620 5 6 2 0 562 0 5585 COLORADO RI V E R R O A D 1 inch = ft. (IN U.S. SURVEY FEET) GRAPHIC SCALE 0030 15 30 60 120 30 BY NO . DA T E BY PROJECT NO. OR 5 3 4 - 0 6 7 0 0 I N M E T R O D E N V E R UN D E R G R O U N D M E M B E R U T I L I T I E S EX C A V A T E F O R T H E M A R K I N G O F BE F O R E Y O U D I G , G R A D E , O R CA L L 2 - B U S I N E S S D A Y S I N A D V A N C E 1- 8 0 0 - 9 2 2 - 1 9 8 7 CE N T E R O F C O L O R A D O CA L L U T I L I T Y N O T I F I C A T I O N RE V I S I O N HI G H C O U N T R Y E N G I N E E R I N G , I N C . PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 - F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m dr a w n b y : ch e c k e d b y : da t e : fi l e : 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , GL E N W O O D S P R I N G S , C O 8 1 6 0 1 SHEET NUMBER 2231025.00 C 2 BE L O D I C R E E K R A N C H , L L C GA R F I E L D C O U N T Y , C O L O . G R A D I N G A N D E R O S I O N C O N T R O L P L A N TR A C T S 1 7 A N D 1 8 GR A N D H O G B A C K R A N C H E S HC E HC E AU G . , 2 0 2 4 GR - 0 1 ORF R EV I E W 559 0 5585 560 0 5595 5590 55 9 0 55 9 5 56 0 0 56 0 5 5585 CR 335 COLORADO RI V E R R O A D 1 inch = ft. (IN U.S. SURVEY FEET) GRAPHIC SCALE 0010 5 10 20 40 10 BY NO . DA T E BY PROJECT NO. OR 5 3 4 - 0 6 7 0 0 I N M E T R O D E N V E R UN D E R G R O U N D M E M B E R U T I L I T I E S EX C A V A T E F O R T H E M A R K I N G O F BE F O R E Y O U D I G , G R A D E , O R CA L L 2 - B U S I N E S S D A Y S I N A D V A N C E 1- 8 0 0 - 9 2 2 - 1 9 8 7 CE N T E R O F C O L O R A D O CA L L U T I L I T Y N O T I F I C A T I O N RE V I S I O N HI G H C O U N T R Y E N G I N E E R I N G , I N C . PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 - F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m dr a w n b y : ch e c k e d b y : da t e : fi l e : 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , GL E N W O O D S P R I N G S , C O 8 1 6 0 1 SHEET NUMBER 2231025.00 C 3 BE L O D I C R E E K R A N C H , L L C GA R F I E L D C O U N T Y , C O L O . DR I V E W A Y E N T R A N C E P L A N TR A C T S 1 7 A N D 1 8 GR A N D H O G B A C K R A N C H E S HC E HC E AU G . 2 0 2 4 DW - 0 1 1 4/ 1 5 / 2 4 TO W N O F N E W C A S T L E C O M M E N T S HC E ORF R EV I E W BY NO . DA T E BY PROJECT NO. OR 5 3 4 - 0 6 7 0 0 I N M E T R O D E N V E R UN D E R G R O U N D M E M B E R U T I L I T I E S EX C A V A T E F O R T H E M A R K I N G O F BE F O R E Y O U D I G , G R A D E , O R CA L L 2 - B U S I N E S S D A Y S I N A D V A N C E 1- 8 0 0 - 9 2 2 - 1 9 8 7 CE N T E R O F C O L O R A D O CA L L U T I L I T Y N O T I F I C A T I O N RE V I S I O N HI G H C O U N T R Y E N G I N E E R I N G , I N C . PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 - F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m dr a w n b y : ch e c k e d b y : da t e : fi l e : 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , GL E N W O O D S P R I N G S , C O 8 1 6 0 1 SHEET NUMBER 2231025.00 C 4 BE L O D I C R E E K R A N C H , L L C GA R F I E L D C O U N T Y , C O L O . ST A N D A R D D E T A I L S TR A C T S 1 7 A N D 1 8 GR A N D H O G B A C K R A N C H E S HC E HC E AU G . 2 0 2 4 DT - 0 1 1 4/ 1 5 / 2 4 TO W N O F N E W C A S T L E C O M M E N T S HC E >>>> COLORADO RIVER ROAD CR 335 COLORADO RIVER ROAD CR 335TRACTS 17 AND 18 ORF R EV I E W 1 DRAINAGE REPORT FOR TRACTS 17 AND 18, GRAND HOGBACK RANCHES NEW CASTLE, GARFIELD COUNTY, COLORADO Access permit application Applicant: Belodi Creek Ranch, LLC Prepared by: High Country Engineering, Inc. 1517 Blake Avenue, Suite 101 Glenwood Springs, CO 81601 (970) 945-8676 For and on Behalf of High Country Engineering, Inc. HCE Project No. 2231025.00 March 15, 2024 Revised: May 14, 2024 Revised: August 8, 2024 2 TABLE OF CONTENTS SECTION PAGE I. PURPOSE .......................................................................................................................... 3 II. LOCATION ....................................................................................................................... 3 III. EXISTING CONDITIONS .............................................................................................. 3 IV. PROPOSED CONDITIONS ............................................................................................ 3 V. SUMMARY ....................................................................................................................... 5 VI. REFERENCES .................................................................................................................. 5 APPENDIX A: Hydrologic calculations APPENDIX B: Storm water storage APPENDIX C: Hydraulic calculations APPENDIX D: Exhibits 3 I. PURPOSE The purpose of this report is to address storm water drainage associated with the proposed grading and driveway entrance improvements, situated within Tracts 16 and 17 of the Grand Hogback Ranches, at County Road 335 (Colorado River Road). II. LOCATION An existing driveway entrance is roughly centered between Tracts 16 and 17 of the Grand Hogback Ranches, opposite of existing Park Drive to the north. III. EXISTING CONDITIONS According to the Soil Survey of Rifle Area, Colorado, parts of Garfield and Mesa Counties, published by the United States Department of Agriculture, in cooperation with the Soil Conservation Service, the soil at the site is primarily Soil Type 51 – Olney Loam. This soil is formed in alluvium derived from sandstone and shale. The surface layer is generally about 12 inches thick. The sub surface layer is generally about 21 inches thick. The sub stratum is generally about 60 inches thick. Permeability is moderate. Available water capacity is moderate. Surface runoff is medium. The erosion hazard is moderate. This soil type is categorized as being within hydrologic soil group B. According Inter-Mountain Engineering Ltd. Letter Re: River Side Village PUD / River Park, dated: December 6, 2004, the runoff coefficient of the soils is: 73. Tracts 17 and 18 are currently undeveloped. The northerly portions are generally or are sparsely vegetation. The southerly regions to the Tracts have out crops, and vegetation, mainly comprised of native trees, shrubs and grasses. Existing storm water runoff generally sheet flows across the site from the South downward towards the North. Runoff is intercepted by existing roadside ditches along County Road 335 (Colorado River Road). The intercepted runoff then passes beneath County Road 335 via existing culverts leading towards the River Park neighborhood, and eventually to the Colorado River to the north. IV. PROPOSED CONDITIONS The Applicant, Belodi Creek Ranch, LLC, intends to make the following improvements:  Expand the limits of the existing driveway entrance, in order to accommodate turning movements of entering and exiting agricultural vehicles  Remove an existing 18-inch culvert at the driveway entrance  Install new 18-inch diameter storm drainage culverts at the existing driveway entrance to accommodate existing roadside drainage  Grade a new storm water retention basin near the northeast corner of Tract 17, to retain the increased tributary developed 25-year runoff volume 4  Grade a new storm water retention basin near the northwest corner of Tract 18 to retain the increased tributary developed 100-year runoff volume  Improve the existing private access road leading to Tracts 17 and 18 to accommodate agricultural vehicles  Grade shallow roadside ditches alongside the improved private access road  Grade a single flat pad within the northerly potions of Tracts 17 and 18, to be utilized for agricultural storage use. The proposed surface of graded areas flat pad is to be overlaid with gravel asphalt millings According to Table 2-2a of Urban Hydrology for Small Watersheds Technical Release 55: hydrologic type B soils that are overlaid with gravel has a curve number of 85. Since the proposed surfacing of the proposed flat pad is to be overlaid with gravel asphalt millings, an increase in surface runoff is anticipated. Therefore, two (2) storm water retention basins, to accommodate the increased 25-year runoff volume are proposed. Tracts 17 and 18 have been analyzed as two (2) watershed basins, under historic and proposed conditions. The peak runoff rates for the basin has been calculated using Soil Conservation Service (SCS) TR-55 Method. A summary for the site peak runoff rates are summarized below in Table 1. According to SGM Letter Re: Grand Hogback Ranches Lots 17 and 18, dated May 24, 2024, maximum allowable runoff rates for the project are as follows: Existing 30” culvert adjacent to west side of site: 25-year: 17.93 cfs 100-year: 32.49 cfs Maximum: 35.86 cfs Existing 24” culvert adjacent to east site of site: 25-year: 7.91 cfs 100-year: 14.27 Maximum: 15.88 Table 1. Basin Watershed Runoff Summary Site Condition Basin (ID) Area (ac.) Composite Curve Number Time Conc. (Hr.) Q25 (c.f.s.) Q100 (c.f.s.) Pre-Developed HI-1W 30.00 73 0.22 9.0 15.7 Pre-Developed HI-1E 28.83 73 0.31 6.5 11.4 Pre-Developed HI-1W & HI-1E 50.83 73 0.22 17.9 32.5 Proposed PR-1W 30.00 73 0.22 9.2 16.0 Proposed PR-1E 28.83 74 0.25 6.7 14.8 Proposed PR-1W& PR-1E 50.83 74 0.22 20.2 35.6 The required 100-year storage volumes have been calculated for Tracts 17 and 18, based upon Soil Conservation Service (SCS) TR-55 Graphical Method, as summarized below in Table 2. 5 The proposed 100-year storage volumes have also been calculated based proposed grading shown on the attached exhibits, using the average end method and comparisons were made, as summarized in Table 2 below. The proposed storage basis have been sized to release rates the following allowable release rates of Basin PR-1W: Existing 30” culvert adjacent to west side of site: 100-year: 32.49 cfs Basin PR-1E: Existing 24” culvert adjacent to east site of site: 100-year: 14.27 Table 2. Proposed 100-year Storage Volume Summary Site Condition Basin (ID) Required 100-Yr Volume (ac.-ft.) Proposed 100-Yr Volume (ac.-ft.) Adequate 100-Yr Storage capacity? Proposed PR-1W 0.024 0.086 Yes Proposed PR-1E 0.020 0.252 Yes Since the proposed 100-year storage volumes, exceed the required 100-year storage volumes, the proposed storage volumes will have adequate storage capacity. V. SUMMARY The applicant intends to overlay surfaces the proposed graded pad with gravel asphalt millings. Therefore, an increase in surface runoff is anticipated. In accordance with Town of New Castle standards, the applicant proposes to construct two (2) storm water retention basins, to accommodate the increased 100-year runoff volumes. The two (2) proposed storm water retention basins are also intended to intercept and sequester any sediments or waterborne pollutants, to provide water quality and thereby protect the aquatic habitat of the Colorado River to the north. VI. REFERENCES 1. Soil Survey of New Castle Area, Colorado, U.S. Department of Agriculture, Soil Conservation Service, May 1985 2. Urban Hydrology for Small Watersheds Technical Release 55 (TR-55),United States Department of Agriculture, Natural Resources Conservation Service, Soil Conservation Service, 1986 3. Precipitation –Frequency Atlas of the Western United States, Volume III-Colorado, National Oceanic and Atmospheric Administration, 1973 4. Letter Re: River Side Village PUD / River Park, Inter-Mountain Engineering Ltd. December 6, 2004 5. Letter Re: Grand Hogback Ranches Lots 17 and 18, SGM, dated May 24, 2024 APPENDIX A Hydrologic Calculations APPENDIX B Storm water storage APPENDIX C Hydraulic Capacity Calculations scale: page: Project No: drawn by: checked by: date: file: HIGH COUNTRY ENGINEERING, INC. 14 INVERNESS DRIVE EAST, STE F-120, ENGLEWOOD, CO 80112 PHONE (303) 925-0544 FAX (303) 925-0547 1517 BLAKE AVENUE, STE 101, GLENWOOD SPRINGS, CO 81601 PHONE (970) 945-8676 FAX (970) 945-2555 www.hceng.com Belodi Creek Ranch LLC Garfield County, CO. TRACTS 17 AND 18 HYDRAULIC CAPACITIES HCE HCE 8 - 8 - 24 C - 01.DWG N.T.S. 2231025.00 APPENDIX C 1 APPENDIX D Exhibits scale: page: Project No: drawn by: checked by: date: file: HIGH COUNTRY ENGINEERING, INC. 1517 BLAKE AVENUE, STE 101, GLENWOOD SPRINGS, CO 81601 PHONE (970) 945-8676 FAX (970) 945-2555 www.hceng.com 1 2231025.00 1" = 1,000' EX-01.dwg 03-15-24 HCE HCE VICINITY MAP GRAND HOGBACK RANCHES TRACTS 17 AND 18 GARFIELD COUNTY, COLO. BELODI CREEK RANCH, LLC CR 335 COLORADO RIV E R R O A D 1 inch = ft. (IN U.S. SURVEY FEET) GRAPHIC SCALE 00100 50 100 200 400 100 BY NO . DA T E BY PROJECT NO. OR 5 3 4 - 0 6 7 0 0 I N M E T R O D E N V E R UN D E R G R O U N D M E M B E R U T I L I T I E S EX C A V A T E F O R T H E M A R K I N G O F BE F O R E Y O U D I G , G R A D E , O R CA L L 2 - B U S I N E S S D A Y S I N A D V A N C E 1- 8 0 0 - 9 2 2 - 1 9 8 7 CE N T E R O F C O L O R A D O CA L L U T I L I T Y N O T I F I C A T I O N RE V I S I O N HI G H C O U N T R Y E N G I N E E R I N G , I N C . PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 - F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m dr a w n b y : ch e c k e d b y : da t e : fi l e : 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , GL E N W O O D S P R I N G S , C O 8 1 6 0 1 SHEET NUMBER 2231025.00 EXDR-01 2 BE L O D I C R E E K R A N C H , L L C GA R F I E L D C O U N T Y , C O L O . PR E - D E V E L O P E D C O N D I T I O N S M A P TR A C T S 1 7 A N D 1 8 GR A N D H O G B A C K R A N C H E S HC E HC E MA R C H , 2 0 2 4 EX - 0 2 3 10 S 85 W Pi t k i n ORF R EV I E W ” ” 25943.5725943.570.000.00 0.000.00 5 6 0 0 55 9 5 55 9 0 56 0 5 5610 5615 5615 5615 5610 5610 5585 5 6 3 5 5 6 3 6 5 6 2 5 5 6 3 0 5615 559 9 5 6 0 5 5600 5595 55905590 5595 5600 5605 5595 5600 5605 5600 5605 5605 5610 56 3 6 56 3 7 5635 5616 5620 5625 5630 5640 5620 5625 5630 5635 5640 56455645 5620 5 6 2 0 5620 5585 CR 335 COLORADO RIV E R R O A D 1 inch = ft. (IN U.S. SURVEY FEET) GRAPHIC SCALE 00100 50 100 200 400 100 BY NO . DA T E BY PROJECT NO. OR 5 3 4 - 0 6 7 0 0 I N M E T R O D E N V E R UN D E R G R O U N D M E M B E R U T I L I T I E S EX C A V A T E F O R T H E M A R K I N G O F BE F O R E Y O U D I G , G R A D E , O R CA L L 2 - B U S I N E S S D A Y S I N A D V A N C E 1- 8 0 0 - 9 2 2 - 1 9 8 7 CE N T E R O F C O L O R A D O CA L L U T I L I T Y N O T I F I C A T I O N RE V I S I O N HI G H C O U N T R Y E N G I N E E R I N G , I N C . PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 - F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m dr a w n b y : ch e c k e d b y : da t e : fi l e : 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , GL E N W O O D S P R I N G S , C O 8 1 6 0 1 SHEET NUMBER 2231025.00 PRDR-01 3 BE L O D I C R E E K R A N C H , L L C GA R F I E L D C O U N T Y , C O L O . PR O P O S E D C O N D I T I O N S M A P TR A C T S 1 7 A N D 1 8 GR A N D H O G B A C K R A N C H E S HC E HC E MA R C H , 2 0 2 4 EX - 0 3 3 10 S 85 W Pi t k i n ORF R EV I E W ” ” sc a l e : pa g e : Pr o j e c t N o : dr a w n b y : ch e c k e d b y : da t e : fi l e : HI G H C O U N T R Y E N G I N E E R I N G , I N C . 14 I N V E R N E S S D R I V E E A S T , S T E F - 1 2 0 , E N G L E W O O D , C O 8 0 1 1 2 PH O N E ( 3 0 3 ) 9 2 5 - 0 5 4 4 F A X ( 3 0 3 ) 9 2 5 - 0 5 4 7 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , G L E N W O O D S P R I N G S , C O 8 1 6 0 1 PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m B e l o d i C r e e k R a n c h L L C Ga r f i e l d C o u n t y , C O . TR A C T S 1 7 A N D 1 8 EX I S T I N G 3 0 " C U L V E R T A N A L Y S I S HC E HC E 8 - 2 2 - 2 4 EX I S T I N G 3 0 " W E S T C U L V E R T C A P A C I T Y S T O R M - 2 . D W G N. T . S . 22 3 1 0 2 5 . 0 0 AP P E N D I X C sc a l e : pa g e : Pr o j e c t N o : dr a w n b y : ch e c k e d b y : da t e : fi l e : HI G H C O U N T R Y E N G I N E E R I N G , I N C . 14 I N V E R N E S S D R I V E E A S T , S T E F - 1 2 0 , E N G L E W O O D , C O 8 0 1 1 2 PH O N E ( 3 0 3 ) 9 2 5 - 0 5 4 4 F A X ( 3 0 3 ) 9 2 5 - 0 5 4 7 15 1 7 B L A K E A V E N U E , S T E 1 0 1 , G L E N W O O D S P R I N G S , C O 8 1 6 0 1 PH O N E ( 9 7 0 ) 9 4 5 - 8 6 7 6 F A X ( 9 7 0 ) 9 4 5 - 2 5 5 5 ww w . h c e n g . c o m B e l o d i C r e e k R a n c h L L C Ga r f i e l d C o u n t y , C O . TR A C T S 1 7 A N D 1 8 EX I S T I N G 2 4 " C U L V E R T A N A L Y S I S HC E HC E 8 - 2 2 - 2 4 EX I S T I N G 2 4 " E A S T C U L V E R T C A P A C I T Y S T O R M - 5 . D W G N. T . S . 22 3 1 0 2 5 . 0 0 AP P E N D I X C