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Home My WebLink AboutNEW BELGIUM BREWERY, PROCESS WATER FACILITY - FDP - 1-95E - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTr 4' FINAL DRAINAGE & EROSION CONTROL STUDY FOR NEW BELGIUM BREWERY PROCESS WATER FACILITY I Prepared for: The Neenan Company 2290 E. Prospect Road Fort Collins, CO 80522 Prepared by: North Star Design, Inc. 700 Automation Drive, Unit I Windsor, Colorado 80550 (970)686-6939 July 30, 2001 Job Number 110-07 LUPINE DR / f l r ai!'Ji• -. - - YARROW l MASON f r CIRCLE U S°� STREET 4g68 Ag6 / r' i J r it J / `- SPURGE L T u` / CIRCLE 2 (7 4949 r ! G ki O;P 49g6 v ZONEAE/ r± anal g68 A_�--_ -- - . —_— -- — It, I — % �. - r t - -' ! t "' i ' Y 7 \ / ('� O T R S T L, C \Q, / CRISTO Ji Py` iDtri n DR'� y EKIS�WG .` ST Dam Agy LINDEN CENifR NEW •Vrf DRIVE 5c-l.Gl Um , TrE;ryrc1) SITE R_OM_ERO ST N BUCKINGHAM STREET i 1 tt-rLEou " 4954 n n 4`Ifi w SO('T/ w FT `SF 1 lU I LOGAN Y > AVE } Q0001 aG�`.�c pjl 1 GPi 9P NI Of" P ZONE AE 4 � s a v a F 1 2 ZONE pti A E o I a� (3) -494i vl VINErDRIVE Burlington Northern Railroad Truji I I a St P OJECT SITE Linden Son C i sto St Center Dr Romero St s Buckingham St QS� W i Logan Q v Sf �° ", Logn Ct i DPffO j ° Ave Q 1 W \ce Sf o� / . o W n Q Sf V cv U IL- J Q c E Lincoln Ave U) W N J Trimble Ct VICINITY MAP APPROXIMATE SCALE: 7" = 600' I I APPENDIX A VICINITY MAP I 0 I I I d I I I I I I I li I II Fd L7 I I d J d d d d d additional volume for water quality extended detention and a water quality outlet structure will be installed. 5.2 Specific Details To limit the amount of silt leaving the site, several erosion control measures shall be implemented during construction. Silt fence shall be placed around the area that will be disturbed and a vehicle tracking pad shall be installed at the entrance off Buckingham Street to control the mud being tracked onto the existing pavement. During overlot grading, disturbed areas are to be kept in a roughened condition and watered to reduce wind erosion. 6. CONCLUSIONS 6.1 Compliance with Standards All computations that have been completed within this report are in compliance with the Overall Drainage Concept for the Overall Development Plan for New Belgium Brewery, the City of Fort Collins Erosion Control Reference Manual for Construction Sites and the Storm Drainage Design Criteria Manual. The site is within the 500 year floodplain and per Chapter 10 of the City of Fort Collins code, no new critical facilities (which includes chemical storage facilities) are allowed within the 500 year floodplain. However, the site have been filled above the 500 year flood elevation in order to remove the site from the 500 year flood plain. 6.2 Drainage Concept The proposed drainage concepts presented in this report and on the construction plans adequately provide for the transmission of developed on -site runoff to the proposed detention pond or to the east following the historic drainage pattern. The onsite drainage facilities (trench drain, pipes) will provide for the 10- year and the 100- year developed flows from Basins 1, lA and 2 to reach the proposed retention facilities. If, at the time of construction, groundwater is encountered, a Colorado Department of Health Construction Dewatering Permit would be required. 6 d I from this basin because a majority of the basin will be landscaped or will remain undeveloped as it currently exists. The amount of runoff from this basin increases only slightly over the historic runoff from this basin. 0 4.3 Drainage Summary Retention ponds are being provided for this site in order to minimize the amount of flow leaving this site and impacting the drainage facilities at the intersection of Buckingham and Vine. The only runoff from this site is from Basin 5 which will be largely undisturbed and the total amount of runoff from this site will actually decrease from the historic runoff amount. In the future, when downstream improvements are made to the storm drain system, the retention ponds may be converted to detention facilities with release pipes. The drainage facilities located on this site will be maintained by the owners of the site. 1 5. EROSION CONTROL & WATER QUALITY 1 5.1 General Concept This site lies within the Moderate Rainfall and Wind Erodibility Zone per the City of Fort Collins Zone Maps. The potential exists for silt movement from the site and into the existing storm system during construction. Potential also exists for tracking of mud onto existing streets which could then wash into existing storm systems. Per the City of Fort Collins Erosion Control Reference Manual for Construction Sites and related calculations in Appendix D, the erosion control performance standard for the subject site is 74.8%. The erosion control plan gives a performance standard of 78.3%. The proposed plan meets the performance standard and utilizes Best Management Practices to limit the amount of sediment that will leave the site. The plan is adequate to meet the intended purpose of erosion control. Refer to the calculations provided in Appendix D for specific details. Permanent water quality on the site will be incorporated into the two proposed retention ponds. Since the ponds will not have a release, the runoff from the site will collect in the ponds and allow sediment and contaminants to settle out of the water. In the future, when the retention ponds are converted to detention ponds, the ponds shall be sized with 4 5 I 0 1 4.2 Specific Flow Routing A summary of the drainage patterns within each basin is provided in the following paragraphs. Subbasin 1 contains the north portion of the site including the access road and a large portion of landscaped area. Runoff from this basin will be collected in a ditch along the south side of the access road and be conveyed east to Retention Pond 1. Subbasin IA contains a small portion of the site including the maintenance building, the chemical storage building and the concrete parking area north of these buildings. The minimum elevation of the chemical storage tanks is 4953. Runoff from this basin will flow north to a trench drain and be conveyed in a 12" PVC to the proposed Retention Pond 1. The storm runoff will be contained in the paved area by mounding the concrete at the north end of the pavement. In the event of a chemical spill the paved area and the mounded concrete will contain the maximum anticipated volume of a chemical truck. A valve system will be installed on the outfall pipe that will be manually activated in the event of a chemical spill. Subbasin 2 contains the center portion of the site including west side of the treatment plant berm, the western access road and a large portion of landscaped area. Runoff from this basin will be collected in a ditch along the west side of the treatment plant and be conveyed south to Retention Pond 2. Subbasin 3 contains the western portion of the site including the west portion of the access road and a large portion of landscaped or undisturbed area. Runoff from this basin will be collected in a swale (that will have a concrete pan in the future) and be conveyed rsouth to the existing detention pond. Subbasin 4 contains a portion of the treatment facility that will not drain out of the treatment plant area. Runoff from this basin will be collected in the treatment ponds which will act as retention facilities for the storm water. This water will eventually be reused in the brewery process as cooling water or be discharged into the sanitary sewer. Subbasin 5 contains the majority of the eastern portion of the site including a large area of the site that will remain without disturbance. It is not proposed to detain the runoff 4 i r r 3.3 Hydrologic Criteria r Runoff computations were prepared for the 10-year minor and 100-year major storm frequency utilizing the rational method. All hydrologic calculations associated with the basins are included in Appendix B of this rreport. Standard Form 8 (SF-8) provides time of concentration calculations for all sub - basins. Standard Form 9 (SF-9) provides a summary of the design flows for all Sub- rbasins and Design Points associated with this site. 3.4 Hydraulic Criteria All hydraulic calculations within this report have been prepared in accordance with the City of Fort Collins Drainage Criteria and are also included in Appendix C of this report. 4. DRAINAGE FACILITY DESIGN 4.1 General Concept In general, the drainage design of the process water facility site will be required to conform to the previously completed Overall Development Plan drainage study that governs the drainage design of this site. The drainage design will be designed to accommodate the Rainfall Intensity -Duration -Frequency curve data adopted by the City of Fort Collins on March 26, 1999. This project will also provide retention ponds in order to minimize the runoff to the existing storm system at the intersection of Buckingham and Vine. r The Treatment Facility will have minor impacts on the amount of runoff from the site. The roadways will all be gravel, recycled asphalt or a material with similar low imperviousness. The remainder of the site will be landscaped or will contain the treatment ponds. The only paved area is north of the maintenance building and runoff from this area will be directed into a retention pond. A retention pond is also provided at the south end of the site. It is proposed to allow the remaining area to continue to drain as it has historically done because the increase in the amount of runoff is very minor. r 3 I 9 2.2 Sub -basin Description The ODP area was divided into two basins and were delineated in the ODP drainage report as the West Basin and East Basin. The West Basin included the area that is currently developed and contains the existing New Belgium Brewery as well as a portion of the undeveloped area. The East Basin included the remaining ODP area and is entirely Iundeveloped. The process water facility is located entirely within the East Basin. 1 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations This report was prepared to meet or exceed the "City of Fort Collins Storm Drainage Design Criteria Manual' specifications. Where applicable, the criteria established in the "Urban Storm Drainage Criteria Manual" (UDFCD), 1984, developed by the Denver Regional Council of Governments, has been used. 3.2 Development Criteria Reference and Constraints The runoff from this site has been routed to conform to previous calculations completed with the Overall Development Plan for the New Belgium Brewery by North Star Design dated February 20, 2001. Detention for this site is provided on site as required in the above -mentioned report. This site is within the 500 year flood plain based on the FEMA maps, panel # 0801020004C dated March 18, 1996. The approximate elevation of the 500 year floodplain at this site is 4953. Part of the site development will include chemical storage which will be required to be above the 500 year floodplain elevation. This is being accomplished by importing fill into the site and setting the lowest finished floor elevation for the building that contains the storage tanks at or above the 4953 elevation. Per Chapter 10 of the City of Fort Collins code, no new critical facilities (which includes chemical storage facilities) are allowed within the 500 year floodplain. However, the site have been filled above the 500 year flood elevation in order to remove the site from the 500 year flood plain. The elevation of the berms surrounding the water treatment ponds is a minimum of 4960 and is higher in some locations. This will prevent overtopping of the treatment ponds in a 500 year storm event. 2 I I TABLE OF CONTENTS TABLEOF CONTENTS............................................................................................................... ... iii 1. GENERAL LOCATION AND DESCRIPTION 1.1 Location and Description of Property......................................................................1 1.2 Purpose of Report ....................................................................................................I 2. DRAINAGE BASINS AND SUB -BASINS 2.1 Major Basin Description..........................................................................................I 2.2 Sub -Basin Description.............................................................................................2 3. DRAINAGE DESIGN CRITERIA 3.1 Regulations..............................................................................................................2 3.2 Development Criteria Reference and Constraints....................................................2 3.3 Hydrologic Criteria..................................................................................................2 3.4 Hydraulic Criteria....................................................................................................3 4. DRAINAGE FACILITY DESIGN 4.1 General Concept......................................................................................................3 4.2 Specific Flow Routing.............................................................................................3 4.3 Drainage Summary ...................................................................................................4 5. EROSION CONTROL & WATER QUALITY 5.1 General Concept......................................................................................................4 5.2 Specific Details........................................................................................................5 6. CONCLUSIONS 6.1 Compliance with Standards....................................................................................5 6.2 Drainage Concept.....................................................................................................6 7. REFERENCES....................................................................................................................7 I W7 I I North Star `, design, inc. July 30, 2001 Basil Harridan City of Fort Collins Stormwater 700 Wood Street Fort Collins, CO 80522-0580 I I I r I I 9 RE: Final Drainage & Erosion Control Study for New Belgium Brewery Process Water Facility Dear Basil, I am pleased to submit for your review and approval, Final Drainage & Erosion Control Study for New Belgium Brewery Process Water Facility. I appreciate your time and consideration in reviewing this submittal. Please call if you have any questions. Sin `Patricia Kro President ii 700 Automation Drive, Unit I Windsor, Colorado 80550 970-686-6939 Phone • 970-686-1188 Fax i 1 i d i i 7 1 J i i i 1 1 i 1 FINAL DRAINAGE & EROSION CONTROL STUDY FOR NEW BELGIUM BREWERY PROCESS WATER FACILITY AUG 2 2001 INLM. i