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" II Current Water Rights and Water Sources The tabulation of water rights that are legally available to meet Cottonwood's needs as shown in Table 0-2. Supply Type Tributary Tributary Supply Source Senior Rights, Cherry Creek Junior Rights, Cherry Creek Subtotal Arapahoe Aquifer Dawson Aquifer Denver Aquifer Laramie-Fox Hills Subtotal Total Water Rights Volume (acre-feet) 141.0 585.0 726.0 995.0 268.0 225.0 182.0 1,670.0 2,396.0 N on- tributary Groundwater Non-tributary Groundwater Non-tributary Groundwater Non-tributary Groundwater Water Quality Representative water quality parameters for Arapahoe wells in this area include a hardness of 54 mg/L (as CaC03), iron of 0.37 mg/L, manganese of 0.02 mgIL and turbidity of 0.38 NTUs. The Laramie-Fox Hills water is considered to be soft, while the Arapahoe waters are moderately hard. Conservation Programs All development in Cottonwood's service area is required to comply with the Uniform Plumbing Code for water savings fixtures. All water uses within the district are metered and outdoor uses are managed through landscaping practices and irrigation scheduling. Cottonwood has developed a non-potable water system to provide water for irrigation purposes from reclaimed wastewater effluent and raw water pumped from shallow alluvial wells along Cherry Creek. This "dual system" is described in the Draft Non-potable Water System Plan, (Wright Water Engineers, 1999). The non-potable water system conserves higher qualityfaw water sources for the potable system and reduces the demands placed on the deeper non-tributary aquifers. A water conservation plan is needed to address water efficiency and dry year conditions when the alluvial water sources along Cherry Creek are unable to operate because of their junior water rights status. Cherry Creek Augmentation Plan ACWW A and Cottonwood operate an augmentation plan that gives the Districts the right to reuse return flows that reach the alluvial aquifer as effluent from municipal wastewater treatment or as deep percolation or surface runoff from lawn watering and other outdoor uses. Cottonwood's augmentation plan recognizes a net rate of recoverable return flow as 45 percent of total well withdrawals. The accounting procedures that will allow quantification of the yields associated with these tributary rights have not been fully implemented so the reliable yields are estimated at this time. Current estimates indicate that Cottonwood can develop 14 1 acre-feet per year from its senior surface water rights plus return flow credits when all adjudicated rights are developed.