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HomeMy WebLinkAboutMONTAVA - PHASE D CORE AND IRRIGATION POND - BDR240006 - SUBMITTAL DOCUMENTS - ROUND 3 - Responses (11) August 7, 2024 Kimberly Nelson Larimer and Weld Irrigation Company WRCC, Inc. 106 Elm Avenue Eaton, CO 80615 RE: Montava Development and Construction, LLC Development Review Application for Phase D Core and Irrigation Pond, Review Number: BDR240006, 2nd Review. Dear Kimberly: As requested by Larimer and Weld Irrigation Company (LWIC), and WRCC, Inc. (WRCC), W.W. Wheeler & Associates, LLC (Wheeler) has reviewed the second round of documents submitted to the City of Fort Collins for Montava Development and Construction, LLC (Montava) Development Review Application for Phase D Core and Irrigation Pond, (Review Number BDR240006). Montava seeks approval of approximately 50 acres of residential development for Phase D along with a non-potable pond and irrigation system. Figure 1 presents a portion of the vicinity map from Montava’s Site Plan. WRCC operates several reservoirs and the No. 8 Outlet Ditch (No. 8 Ditch) which is located on the west side of the Phase D development. The No. 8 Ditch delivers irrigation releases from the No. 8 Reservoir, Annex Reservoir, and Elder Reservoir to the Larimer and Weld Canal (LWC) which LWIC owns and operates. This letter provides our comments on this second round of documents which we obtained from the City of Fort Collins public records website on July 24, 2024. In addition to the documents obtained from the website, Wheeler was also provided with two comment letters prepared by Heidi Hansen, Water Utilities Development Review Manager with the City of Fort Collins. In 1986, Anheuser Busch and LWIC signed an agreement (1986 Agreement) which provided for discharge of drainage into the LWC as described in the Agreement. Throughout the second-round documents submitted by Montava for Phase D, Montava still plans to discharge stormwater from its development into the LWC pursuant to this agreement. This letter does not address these issues, as they are legal in nature. Figure 1 – Vicinity Map depicting Phase D project boundary. The following sections provide our comments and a list of documents reviewed. Comment Response Filename: 1_CMNT_RESPONSE_Montava Phase D Core_BDR_Rd2.pdf 1. No comments. Martin/Martin Letter to Heidi Hansen re: Proposed Drainage Outfall for Montava Phase D Filename: 1_DITCH CMNTS_RESPONSE_2024.05.31_Phase D Outfall Response to COFC.pdf 2. Please provide the hydraulic analysis used to determine that the existing 12 inch high by 24-inch-wide wooden box culvert has a capacity of 50 cfs before the railroad overtops. Additionally, please provide documentation of any assumptions used in the analysis. RESPONSE: Existing conditions SWMM model with approximate wooden box culvert capacity can be downloaded using the following link. HY-8 analysis indicates that the culvert is barrel controlled with a capacity closer to 23 cfs prior to railroad overtopping. HY-8 calculations are linked below. SWMM Models: https://martinmartin.box.com/s/ciic1yacs2aampfmlhw9lkikmbiqhznw HY-8 Calculations: https://martinmartin.box.com/s/tax7ln7hxgzji5y9c8u7nl0hpzjf5dbr 3. Please provide the SWMM model used to estimate the drain down time of the fully developed Phase D and undeveloped area draining to the Railroad box culvert. RESPONSE: Pre- and post-project SWMM models can be downloaded using the following links. SWMM Models: https://martinmartin.box.com/s/ciic1yacs2aampfmlhw9lkikmbiqhznw 4. Please provide any analysis Montava completed on of the capacity on the 24-inch Corrugated Metal Pipe culvert and drainage ditch connecting the wooden box culvert to the Larimer and Weld Canal? RESPONSE: The normal depth full flow capacity of the existing ditch downstream of the 24in-wide by 12in-high box culvert is approximately 70 cfs. HY-8 analysis of the existing 24-inch CMP culvert, showing approximately 20 cfs capacity, can be downloaded using the link below. HY-8/Normal Depth Calculations: https://martinmartin.box.com/s/tax7ln7hxgzji5y9c8u7nl0hpzjf5dbr Map of Montava Property and Briky Lands Filename: 1_DITCH CMNTS_RESPONSE_Birky Order Map and Summary v2.pdf 5. No comments. Response to LWIC and WRCC Comment Filename: 1_DITCH CMNTS_RESPONSE_Letter in response to Ditch Company Arguments.pdf 6. No Comments. Project Information and Narrative, Updated July 17, 2024. Filename: 1_NARRATIVE_Montava Phase D Core_BDR_Rd2.pdf 7. No Comments. Round 2 Lot Typicals Filename: 2_ARCH_Montava Phase D Core_BDR_Rd2.pdf 8. Wheeler did not review this document. Landscape Plan Comment Responses Filename: 2_LANDSCAPE_Montava Phase D Core_BDR_Rd1_RESPONSES.pdf 9. Wheeler did not review this document. Round 2 Overall Landscape Plan Filename: 2_LANDSCAPE_Montava Phase D Core_BDR_Rd2 10. Wheeler did not review this document. Lighting Plan Comment Responses Filename: 2_LIGHT_Montava Phase D Core_BDR_Rd1_RESPONSES.pdf 11. Wheeler did not review this document. Round 2 Lighting Plans Filename: 2_LIGHT_Montava Phase D Core_BDR_Rd2.pdf 12. Wheeler did not review this document. Site Plan Comment Responses Filename: 2_SITE PLANS_Montava Phase D Core_BDR_Rd1-RESPONSES.pdf 13. No Comments. Round 2 Site Plans Filename: 2_SITE PLANS_Montava PhD Core_BDR_Rd2.pdf 14. No Comments. Montava Subdivision Phase D Boundary Closure Calc Filename: 3_CLOSURE-PLAT_Montava Phase D Core_BDR_Rd2.pdf 15. Wheeler did not review this document. Comments on Final Plat for Montava Subdivision Phase D. Filename: 3_PLAT_Montava Phase D Core_BDR_Rd1_RESPONSES.pdf 16. No Comments. Round 2 Final Plat for Montava Subdivision Phase D. Filename: 3_PLAT_Montava Phase D Core_BDR_Rd2.pdf 17. No comments. Requirements for Utility Plans Filename: 4_UTILITY PLANS E-4 Checklist_Montava Phase D Core_BDR_Rd1.pdf 18. No comments. Potable Water Analysis for Montava Phase D, July 17, 2024. Filename: 4_UTILITIES Potable Water Report_Montava Phase D Core_BDR_Rd2.pdf 19. No comments. Sanitary Sewer Analysis Results for Montava Phase D, July 16, 2024. Filename: 4_UTILITIES Sanitary Sewer Report_Montava Phase D Core_BDR_Rd2.pdf 20. No comments. Utility Checklist Filename: 4_UTILITY PLANS E-4 Checklist_Montava Phase D Core_BDR_Rd2.pdf 21. Wheeler did not review this document. Round 2 Utility Plans Filename: 4_UTILITY PLANS_Montava Phase D Core_BDR_Rd2.pdf 22. No comments. Round 2 PDP Final Drainage Report for Montava Subdivision Phase D, July 17, 2024 Filename: 5_DRAINAGE_Montava Phase D Core_BDR_Rd2.pdf 23. LWIC’s attorney has indicated that any drainage through the wooden box culvert under the railroad is not a part of the 1986 AB Agreement, and therefore, LWIC does not allow a change to the historical quantity, quality, type, rate, or location of water draining into the LWC. Wheeler reviewed the proposed drainage documents and believes that the volume of discharge will increase with Phase D, and thus is not acceptable. Please revise the plans to meet the LWIC requirements or develop a system that conveys the runoff to the Cooper Slough on the south side of the LWC canal. RESPONSE: It is Montava’s position that the existing 24in-wide by 12in-high box culvert represents the point source identified in the 1986 AB Agreement, which allows Montava to discharge at the historic rate of this culvert crossing. This is well described in the memorandum from Steve Bushong to city staff dated Sept 11, 2024 in response to Ryan Donovan’s letter dated August 7th, 2024; a copy the memorandum is included with our Round 3 re-submittal documents. Proposed detention for the Phase D development will reduce 100-year developed discharges to historic 2-year rates. Note that the AB agreement acknowledges that there will be an increase in stormwater volume, and this increase is acceptable if historic 100-year rates are maintained. Comments on Stormwater Management Plan for Montava Subdivision Phase D. Filename: 5_SWMP_Montava Phase D Core_BDR_Rd1_RESPONSES 24. No comments. City of Fort Collins Information for Development Agreements Filename: 6_DA_INFO_Montava Phase D Core_BDR_Rd2.pdf 25. Wheeler did not review this document. Development Agreement Between the City of Fort Collins and Montava Partners, LLC and Montava Development & Construction LLC for Montava Subdivision Phase D Core and Irrigation Pond. Filename: 6_DA_Montava Phase D Core_BDR_Rd2.pdf 26. Wheeler did not review this document. Utility Plans for Montava Non-Pot Pump Station, July 2024. Filename: 6_NON-POT CONSTRUCTION PLANS_Montava Phase D Core _BDR_Rd2.pdf 27. No comments. Appendix E-4, City of Fort Collins, Requirements for Utility Plans Filename: 6_NON-POT E4 Checklist_Montava Phase D Core_BDR_Rd2.pdf 28. Wheeler did not review this document. Non-Potable Irrigation System Report For Montava Subdivision, July 2024. Filename: 6_NON-POT SYSTEM REPORT_Montava Phase D Core_BDR_Rd2.pdf 29. No comments. Responses to May 21, 2024 Comment Letter. Filename: 6_OTHER_LWIC Wheeler-COMMENT RESPONSES_Montava Phase D Core_BDR_Rd2.pdf 30. The Montava response indicates that the historic 2-year and 100-year peak discharge estimates and drainage patterns relative to Phase D of Montava are outlined on the exhibit titled “2024.07.09_Historic Land Use Conditions.” The response includes a figure at the end with a file name “2024.06.14_Historic Land Use Conditions.” Wheeler assumes this is the correct figure, even though the dates are different. Please confirm. RESPONES: Confirmed. This is the correct exhibit. 31. The 2024.06.14 Historic Land Use Conditions figure shows that historic basin 32 drained to the northeast corner of Mountain Vista and the BNSF railroad, which Wheeler believes ultimately ended up in the Birky detention area. A review of 2020 lidar data indicates that runoff from this area continues to drain to the northeast corner of Mountain Vista and the BNSF railroad where it is inadvertently detained. It is unclear to Wheeler how, or if this runoff reaches the LWC under current conditions. However, Phase D proposes to re-route this runoff to the LWC which we believe may be a change to the historical location that the runoff was discharged to the LWC. Montava should provide additional details and analysis on how and where this runoff historically flowed. RESPONSE: The exhibit and supporting topography show that Basin 32 drains to the NORTHWEST corner of Mountain Vista and the BNSF Railroad, where it combines with runoff from the nearly 26 square mile Cooper Slough watershed, overtopping Mountain Vista Dr. and draining to the existing 24in-wide by 12in-high box culvert under the BNSF Railroad and into the LWC. Flows from this basin do not enter the Birky Order detention area, as there is a low point in Mountain Vista directly west of the BNSF Railroad crossing. Montava is not proposing re-routing of flow to the LWC. Stormwater from Phase D will discharge to the southeast corner of Mountain Vista and Giddings at or below historic rates and enter the historic drainage path to the LWC, as allowed by the 1986 AB Agreement. 32. The figure also shows that basin 27 drains to an existing open channel which Martin and Martin indicates drains to the wooden box culvert under the railroad. Wheeler staff visited the site and were unable to locate any such channel. Instead, it appears that the channel has been blocked by berms for the pivot sprinkler towers. Even if these berms were removed or pipes installed under the berms, the channel ends after approximately 700 feet at an inlet structure with an 8-inch clay pipe. Appendix A of this letter provides pictures of this inlet structure. Wheeler also located a concrete box in a depression in the field approximately 1400 feet from this inlet structure. This box allowed water to drain into the structure and had several inlet pipes, with one or two outlet pipes. Wheeler was unable to confirm that the channel inlet pipe reaches this concrete box, or that the concrete box drains to the area near the wooden box culvert. However, the notion that the historic flow reached the LWC via an existing channel is incorrect. It is possible that the stormwater historically discharged from Phase D was detained or that the flow rates were otherwise reduced from the 50 cfs that Montava believes can pass under the railroad. RESPONSE: Martin/Martin and Montava recognize the existing agricultural tile drain system within the field southeast of Mountain Vista and Giddings, which is not being relied on as a stormwater drainage component for Phase D. Topography in this area supports the fact that the 26 square mile Cooper Slough watershed drains to and backs up behind the BNSF Railroad embankment and enters the existing 24in-wide by 12in-high box culvert and ultimately the LWC. This historic drainage path has been recognized by stormwater modeling that dates back as far as 2006. The 50 cfs capacity of the existing BNSF box culvert is the 100-year flow at the headwater depth prior to overtopping the railroad embankment, based on the SWMM model included. Analyzing the same condition using HY-8 resulted in a peak discharge of 23 cfs, considering barrel capacity. 33. Please provide any model runs used to develop the 2024.06.14 Historic Land Use Conditions figure, or the 2024.07.09_Historic Land Use Conditions figure. RESPONSE: SWMM model linked below. SWMM Models: https://martinmartin.box.com/s/ciic1yacs2aampfmlhw9lkikmbiqhznw 34. The response indicates that the “proposed Phase D 2-year and 100-year peak discharge estimates and drainage patterns are outlined in the exhibit Titled 2024.07.09_Phase D Land Use Conditions. Wheeler was unable to locate this document. Please provide this document. RESPONSE: Document date was updated and is linked below. 2024.07.31_Phase D Land Use Condition: https://martinmartin.box.com/s/rgjkifka4zg4us4p8lca9h5gotfjriuf 35. Montava indicates in its response that “Based on the 1986 AB-LWIC agreement, if development within Montava west of BNSF (excluding Phase G) meets the historic 100- year capacity of the existing 24” (W) x 12”(H) point source, the existing stormwater outfall can be utilized prior to or as part of the implementation of the ultimate stormwater infrastructure solution.” As described above, and based on information provided by LWIC’s legal counsel, Wheeler disagrees. LWIC does not allow a change to the historical quantity, quality, type, rate, or location of water draining into the LWC. Furthermore, the June 18, 2024 letter from Heidi Hansen indicates that the city will not accept the current configuration of the wooden box culvert or the existing 24-inch CMP pipe without further analysis, and a structure that “… meet(s) the standards of the Irrigation Company …”. Because of the change to the historic stormwater discharge, Wheeler recommends that Montava develop a pipeline over the ditch which conveys the stormwater to the Cooper Slough. RESPONSE: It is Montava’s position that the existing 24in-wide by 12in-high box culvert represents the point source identified in the 1986 AB Agreement, which allows Montava to discharge at the historic rate of this culvert crossing. Proposed detention for the Phase D development will reduce 100-year developed discharges to historic 2-year rates. Note that the AB agreement acknowledges that there will be an increase in stormwater volume, and this increase is acceptable if historic 100-year rates are maintained. July 17, 2024 Montava Response to June 18th Letter Re: Proposed Drainage Outfall for Montava Phase D. Filename: 6_OTHER_Stormwater-COMMENT RESPONSES_Montava Phase D Core_BDR_Rd2.pdf 36. Please provide copies of both BNSF railroad crossing agreements referenced in the letter. RESPONSE: BNSF Railroad crossing agreements are linked below. Railroad Crossing Agreements: https://martinmartin.box.com/s/2mu2qsqwotftgrd4rw9rja0sw8eyvlv3 37. These responses are largely legal in nature. Any engineering issues have been raised above, and thus Wheeler has no further comments on this document. RESPONSE: Comment noted. Thank you. Comment Response, ELCO Comments on Utility Plans Filename: 6_OTHER_Utility Plans-ELCO-COMMENT RESPONSE - Montava Phase D Core_BDR_Rd1.pdf 38. Wheeler did not review this document. Comment Response ELCO Comments on Water Plan and Profiles Filename: 6_OTHER_Water Line Plan and Profiles-ELCO-COMMENT RESPONSE - Montava Phase D Core_BDR_Rd1 39. Wheeler did not review this document. PFA Fire Turn Templates Filename: 6_PFA_Truck Turn Ex_Montava Phase D Core_BDR_Rd2.pdf 40. Wheeler did not review this document. Traffic Impact Study, Montava Phase D, July 2024 Filename: 6_TRAFFIC_Montava Phase D Core_BDR_Rd2.pdf 41. Wheeler did not review this document. Variance Request Response Filename: 6_VAR-ENG Centerline Radius_Montava Phase D Core_BDR_Rd1_RESPONSES.pdf 42. Wheeler did not review this document. Variance Request Filename: 6_VAR-ENG Centerline Radius_Montava Phase D Core_BDR_Rd2.pdf 43. Wheeler did not review this document. Variance Request Response Filename: 6_VAR-ENG Centerline Tangent_Montava Phase D Core_BDR_Rd1_RESPONSE.pdf 44. Wheeler did not review this document. Variance Request Filename: 6_VAR-ENG Centerline Tangent_Montava Phase D Core_BDR_Rd2.pdf 45. Wheeler did not review this document. Variance Request Filename: 6_VAR-ENG Centerline Tangent2_Montava Phase D Core_BDR_Rd2.pdf 46. Wheeler did not review this document. Variance Request Response Filename: 6_VAR-ENG Roadway Sections_Montava Phase D Core_BDR_Rd1_RESPONSES.pdf 47. Wheeler did not review this document. Wheeler recommends that Montava address the issues above before LWIC provides any notice to the City of Fort Collins approving these plans. In addition to the issues above, there are several legal issues that need to be resolved. The issues identified above are based on the data and documents we have currently available and may change as additional information becomes available. Sincerely, W. W. Wheeler & Associates, Inc. Hayden Strickland, P.E. Cc via Email: Autumn Penfold, Andy Pineda, Linda Bower, Lawrence Custer Grasmick Jones & Donovan, LLP Ryan Donovan, Lawrence Custer Grasmick Jones & Donovan, LLP File Location: R:\1900\1953-LWIC\01_Montava_PhaseD\7_Documents\Rd 2 Aug 2024\08-07-24 Phase D Round 2 Comments.docx Appendix A – Site Visit Photos Photo 1 – Looking Northwest at drainage channel. Note pivot tower berm blocking flow path. Flow direction is from top of photo to bottom. Inlet structure in poor condition. See Photo 2 for pipe diameter. (Location: 40.608039, 105.018369) Photo 2 – Drainage channel outlet pipe. Clay tile approximately 8 inches. Invert filled with debris. (Location: 40.608039, 105.018369) Photo 3 – Drainage structure located in depression of field. Two entrances to the structure from the surface. Box dimensions are 5 feet wide by 5 feet wide (Location: 40.605297, 105.014983) Photo taken looking south. Photo 4 – Inside of drain structure. Photo taken looking north from south surface entrance. Pipes shown are likely inflow to the box. Photo 5 – Inside of drain structure. Photo taken looking south from north surface entrance. Pipe on the right, and in lower left corner likely inflow pipes. The pipe on the far wall center is the lowest pipe in elevation and likely an outlet pipe. The pipe in the right corner of box may be a drain or an inlet pipe.