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HomeMy WebLinkAboutRUDOLPH FARMS INFRASTRUCTURE PROJECT - FDP220010 - SUBMITTAL DOCUMENTS - ROUND 3 - SUPPORTING DOCUMENTATION Memorandum The Rudolph Farm project will utilize available well and surface water to serve all landscape areas within the development and to fill the three on-site ponds. System Overview Irrigation water from the well and surface water sources, as well as site stormwater will be directed to three on-site pond locations, as detailed in the current drainage plan prepared by Northern Engineering. Pond 2, with a proposed surface area of 2.42 acres, will serve as the primary collection pond for storage of irrigation water and pond make-up water to be distributed to the secondary ponds 1 and 3. Pond 2 will receive water from the surface water sources and from the on-site wells such that water delivery will be available to maintain the target water level. Water will enter from the existing surface ditch, located on the West side of the site, that will convey the available surface and well water. Make-up water will be transferred to ponds 1 and 3 via an irrigation pumping station which will draw water from pond 2 and into distribution piping to serve irrigation needs and maintain the water elevation in each of the ponds. The irrigation pump station will employ multiple variable speed pumps to provide system redundancy and to enable the system to respond efficiently to a wide range of system flow rates. The pumps will maintain pressure in the system in order to provide a ready supply for the various irrigation systems throughout the site and for the pond fill needs. The ponds are intended to function as wet ponds with storm detention capacity. Pond water levels will be maintained continuously by a float fill system so that storm flows will pass over and will not be held beyond the stormwater detention limits. The proposed pond wet elevations are as follows. (See the Northern Engineering Drainage Plans for more information). Pond 1 = 4904.10 Pond 2 = 4911 Pond 3 = 4919 It is expected that water levels in pond 2 would recede only during peak season irrigation operations. Water delivered from each source will be measured upon delivery to the pond system as will the volume of water transferred through the pump station. In the event that stormwater is received during irrigation operations or at any time when the pond is below the maintenance level, the water volumes received in the pond and the water volume discharged through the pumping system can be tracked via appropriate telemetry to transfer the appropriate volume of stormwater for discharge directly to the TRIC. Date: November 2, 2022 To: Mr. Blaine Mathison, Northern Engineering From: Hines Inc Re: Rudolph Farm - Non-Potable Water Supply Overview Colorado Office 323 West Drake Road, Suite 204 Fort Collins, CO 80526 Phone: 970-282-1800 Fax: 970-226-4662 Rudolph Farms – Non-Potable Water Supply Overview November 2, 2022 2 Water Supply The project will be supplied from a combination of well and surface water sources which will be delivered to the irrigation pond for distribution. Based on previous analysis, up to 304 acre-feet of water may be available in an average year from the various sources provided. Compared with the approximately 78 acre-feet required for irrigation, an excess of native waters will be available for the site. Currently, two of the existing wells are permitted for residential use & only offer the right to irrigate up to one (1) acre at the original home sites. We do not believe it will be cost effective or practical to maintain these wells for on-going site irrigation. Existing Wells There are two wells in the northwest corner of the property that have been discharged to a point in the onsite lateral just east of Vixen Dr. for delivery to the irrigation pond. As described in our 2016 irrigation water use analysis, the following water resources are available. 1. Well # 2-11993 a. Decreed for a substantial pumping rate of 1.65 CFS however, b. Production records state the well only operates for 15 days per season then runs dry c. Additionally, this well is decreed to be used for a 40-acre section at the northeast portion of the project site. 2. Well #’s 8-19642-1 & 7-19642-2 a. Together these wells are permitted for 240 acre-feet of water per year. b. This well is decreed to be used for a 40-acre section at the northwest portion of the project site. Surface Water From the East, the property is provided Kitchel Reservoir water via an open ditch that runs northwest from the reservoir, crosses CR5, runs along the North and then West side of several 10 acre lots, then West along the North side of Kitchel Estates to the northeast corner of the Rudolph property. It is reported that this water source has rarely been used in the last 10 years. From the North, the property is able to receive Eaton Ditch, Larimer-Weld and No. 10 water. This water is delivered via ditches that start where the Larimer-Weld ditch crosses Hwy 14, and then run West along the South side of Hwy 14, then turn South near Sunchase Dr and continue South along the West side of the Clydesdale neighborhood via a combination of pipes and open ditches. This is the primary delivery route for ditch water to the property. a. In an average year both surface rights (Kitchell & Larimer & Weld) provide an estimated 61 acre-feet of water. b. This water can be used anywhere on the property c. In a dry year, an estimated 14 acre-feet may be available for use. d. *Please note: Kitchell does not have good records for available water & effective delivery rates for the property. While up to 74 acre-feet may be available as a maximum allowance, historic notation indicates that none of the current delivery infrastructure to the property is metered. Delivery structure efficiency should be researched and reviewed. Surface water and well water will be conveyed through the on-site ditch which flows from the NE corner of the site to the West and then South to the proposed irrigation pond location. Rudolph Farms – Non-Potable Water Supply Overview November 2, 2022 3 Water Source Management Strategies Surface Water o Surface water supplies will be delivered to the site via surface ditch delivery. o A measurement structure meter, meeting ditch company standards, will be utilized to chart water deliveries to the site o The community water manager will coordinate deliveries with the ditch company ditch rider and irrigation system manager o Pond water levels will be managed utilizing water level sensors located at the pond Well Water Supplies o Use of well water will be prioritized during irrigation shoulder seasons, when surface water supplies may not yet be available and when minor mid-season irrigation water requirements arise. o Delivery from each well to the pond will be controlled via lake water level sensor and coordinated electronically with surface water deliveries. o Each well will include a meter with remote read and monitoring capabilities to manage water supplies. A surface water delivery schedule, utilizing average year yields and deliveries by month, should be developed by a water resource engineer as a general guideline. A monthly recording of irrigation demand requirements will be kept by community management. Water deliveries amounts, from both well & surface water sources will also be provided for reconciliation of supply and demand calculations and reporting. The non-potable water system, storage, distribution and irrigation will be designed to match the decreed area requirements for each water source. Irrigation water dedication will be required for each residential lot to serve exterior lot landscape irrigation purposes & open space landscape irrigation requirements. Hines has provided the following to facilitate more detailed water planning, raw water dedication negotiation, improved water conservation planning & a reduction of developer costs. Rudolph Farms – Non-Potable Water Supply Overview November 2, 2022 4 Estimated Water Demand Based on Hines analysis of combined irrigation demands to serve both open space & residential (on-lot) water use calculations, the total irrigation water demand for the project is estimated to be approximately 78 acre-feet. Interior water use dedication requirements for this project are estimated at 203 acre-feet. ELCO does not provide final tap sizing for commercial taps until final building design. The above amounts are an estimate based on historic projects and discussion with ELCO. The exact amount may vary with some significance depending on usage and tenant needs. IRRIGATION REQUIREMENTS AND LANDSCAPE AREA CALCULATIONS The following parameters have been utilized to estimate irrigation water use for the project site. Please refer to the attachment below for Water Use Estimates organized by Project Area. Landscape water use and irrigation water demands have been calculated using: o Regional evapotranspiration (ET) rates averaged over 30-years o Specific plant coefficients based on proposed landscape material o Irrigation equipment efficiency data based on Rotor sprinklers serving large turf and native grass Spray sprinklers serving small turf areas Drip irrigation serving trees and shrubs o 8-10 hour watering window on common landscape areas Turf, shrub, & tree plant material will be permanently irrigated Turf is assumed to be a bluegrass/fescue blend Native areas will be irrigated for establishment o Irrigate only during an establishment period of approximately 3 years Irrigation Water Budget Summary Equipment Area (acres) Month Plant Water Req'mt (in) Monthly Water Req'mt Monthly Water Use Plant Water Req'mt (in) Monthly Water Req'mt (in) Monthly Water Use (gal) Plant Water Req'mt (in) Monthly Water Req'mt (in) Monthly Water Use (gal) January 0.00 0.00 -0.00 0.00 -0.00 0.00 - February 0.00 0.00 -0.00 0.00 -0.00 0.00 - March 0.00 0.00 -0.00 0.00 -0.00 0.00 - April 1.35 2.08 597,257 0.99 1.10 280,433 0.54 0.77 496,894 May 3.90 6.00 1,725,409 2.86 3.18 810,138 1.56 2.23 1,435,471 June 4.95 7.62 2,189,942 3.63 4.03 1,028,253 1.98 2.83 1,821,944 July 5.33 8.19 2,355,847 3.91 4.34 1,106,150 2.13 3.04 1,959,970 August 4.65 7.15 2,057,219 3.41 3.79 965,934 1.86 2.66 1,711,523 September 3.38 5.19 1,493,143 2.48 2.75 701,081 1.35 1.93 1,242,235 October 1.35 2.08 597,257 0.99 1.10 280,433 0.54 0.77 496,894 November 0.00 0.00 -0.00 0.00 -0.00 0.00 - December 0.00 0.00 -0.00 0.00 -0.00 0.00 - Subtotal (inches/year) Subtotal (gallons/year) Subtotal (acre-feet/year) Peak Flow (gpm) PROJECT DEMANDS TOTAL SOUTH NORTH IRRIGATED ACRES 44 17 26 GALLONS/YEAR 25,353,428 9,763,781 15,589,647 ACRE FEET/YEAR 78 30 48 PEAK SEASON GPM 434 167 267 INSTANTANEOUS PEAK GPM REQUIREMENT 521 201 321 14.23 9,164,932 157.0588.63 28.1315.87 5,172,422 20.29 188.77 38.31 33.81 11,016,074 Native Rotor 23.85 Turf Spray 10.65 Shrub Drip 9.44 Interior Water Use Dedication Requirements Annual Allotment PIF Gallons CBTor NPI JDC. WSS $ 47,238,000 203 217 $2,963,036 21,411,000 92 99 1,303,692 25,827,000 111 119 1,659,344 ELCO Raw Water Dedication PROJECT TOTAL PARCELS NORTH OF CANAL PARCELS SOUTH OF CANAL Raw Water Dedication Requirements AcFt Rudolph Farms – Non-Potable Water Supply Overview November 2, 2022 5 o Following the time for establishment, Native Grasses will be removed from seasonal irrigation pending significant drought. o Removing Native Grass from long-term supplemental irrigation may reduce on- going irrigation water requirements by nearly 40-acre feet annually. o We recommend allotting a portion of annual water use to maintain native grasses in a healthy state of dormancy during significant drought. This may equate to 30% of the above amount noted depending on the quality of establishment, maintenance practices, & severity of drought. Open Space Landscape Area Please refer to the attachments below for a specific breakdown of landscape areas as provided by the project Landscape Architect. Additional clarifications are provided below. The total landscaped area for the project is 44-acres, 28-acres of which is dedicated to common area open space. 16-acres consist of landscape areas located within private areas of the project. Landscape typologies include: Manicured turf Mulched planted beds ‘Dryland’ Native Seed areas o Receive establishment water for 2-5 years after which supplemental irrigation will be turned off pending severe drought Annual Project Estimated Water Use: 78 acre-feet The South portion: o 30 acre-feet to meet annual irrigation requirements The North portion: o 48 acre-feet to meet annual irrigation requirements Please refer to the attached Water Budget tables and the Irrigation Masterplan which document landscape assumptions, & overall water use requirements by landscape type for residential lots & open space areas as described by the landscape architect.