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secondary storage, while maintaining atwo-foot freeboard. The volume of this ditch is over 6.5 million gallons. In addition, it is proposed to decrease the sprinkler Mn washings to e times Per week after the const=joni2f he nvw.milk-bay. This should reduce Milk Barn water usage by �..�..� 75%. It is also proposed to divert rainfall runoff from the freestall roofs to Field No. 8, directly east of the freestall barns. By incorporating theses two Best Management Practices (BMPs) of decreasing sprinkler pen water usage and diverting rainwater runoff to the cropland field, the following calculation demonstrates that the pond will have marginally sufficient volume for 120 day storage: 9,796,000- 1,921,500(75%of 2,562,000)- 1,619,046(Rainfall from freestall roofs onto Field No.8)_ 6,255,454 gallons (Volume of holding pond= 6,551,200 gallons). NUTRIENT WATER AND IRRIGATION WATER DISTRIBUTION SYSTEM-HOME RANCH The nutrient and irrigation water distribution system, and the tailwater recovery system for the Home Ranch isFresh irrigation water can be obtained from two sources: The on-site irrigation well at the west end of the freestall barns, or from Beaver Slough at the north end of the Home Ranch. The irrigation well is used primarily for dilution of the separation basin and holding pond water at the beginning of the irrigation season, and then as irrigation backup throughout the irrigation season. However, irrigation water costs are significantly less expensive using water from Beaver Slough. Irrigation water is pumped from Beaver Slough into an unlined ditch at the north end of the Home Ranch. Water travels westward where it is pumped over a tailwater ditch, to the unlined primary — irrigation water conveyance ditch,traversing north-south. The water then travels south to a 90' turn heading east and flows easterly along the south end of the dairy facility, then northerly, where it picks up nutrient water from the separation basins. This water then travels easterly again when it encounters the holding pond. At this point, there is a mixture of fresh irrigation water, tailwater, separation basin water and holding pond water. However, the volume of irrigation water is substantially higher than nutrient water at this point. Beyond the holding pond to the east, this blend continues another 1,250 feet in an unlined ditch where two pumps at the southeast corner of the Home Ranch "pickup"the blended water and pump it into concrete-lined ditches. Irrigation discharge from these concrete ditches can occur to all cropland fields and can be controlled by semi-circular headgates. As referenced above, irrigation water cannot impact Beaver Slough due to a 15-foot elevational difference. To maximize uniform water distribution, whether for furrow irrigation for silage corn or flood irrigation for grain, all cropland fields are laser leveled with the proper slope prior to planting. TAILWATER RECOVERY SYSTEM-HOME RANCH Irrigation flow patterns and field numbers are illustrated on the Site Plan for the Home Ranch and a Site Schematic for the Acampo Ranch. As referenced, the tailwater return system for the Home Ranch is a"closed-loop" system. The system is closed-loop because all tailwater can either flow back into the irrigation water conveyance ditch via tailwater ditches, or back into the holding pond, to be re-circulated directly back into the irrigation system throughout the Home Ranch. Because of this arrangement, tailwater and irrigation water cannot escape from the Ranch, unless there was a failure of both pumps at the southeast corner of the Ranch, which could be considered a discharge point. The main tailwater ditch runs north-south, parallel to the east of the primary irrigation water conveyance ditch. If land application of retained rainwater and nutrient water within the storage structures must be necessary during the rainy season, the referenced pumps can be turned on and the water re-circulated over the cropland,throughout the conveyance system, and re-captured by the tailwater ditch system. -10- Chesney Consu.Cting