The Town of Silver City initiated a water conservation planning process to evaluate ways to sustain and conserve its municipal groundwater supply. The water conservation plan was developed with guidance and review of a stakeholder group that included representation from the Town, water associations, environmental groups, local committees, the local business community, the New Mexico Environment Department, the Southwest New Mexico Council of Governments, and the general public. The Town of Silver City supplies water to about 10,000 residents within the Town and to additional customers outside of the Town, serving a total of about 5,300 homes and 600 commercial accounts. Additionally, the Town water system sells water to five water associations (the Arenas Valley Water Association, Pinos Altos Mutual Domestic Water Consumers’ Association [MDWCA], Rosedale MDWCA, Tyrone Property Owners Association (TPOA), and Tyrone MDWCA), resulting in a total population receiving water from the system of about 20,000. The total metered production in 2011 was 926,261,000 gallons (2,842 acre-feet) and in 2012, 823,500,000 gallons (2,527 acre-feet).
Silver City currently relies exclusively on groundwater from well fields located in both the Mimbres and Gila-San Francisco Basins (from aquifers of the Upper and Middle Gila Group). Water is supplied by Frank’s well field (two wells in production), the Gabby Hayes and Anderson wells, and the Woodward well field (five wells in production). The Frank’s well field is located in the Gila-San Francisco Basin; the Woodward well field and Anderson and Gabby Hayes wells are located in the Mimbres Basin. Prior to identifying conservation programs, it is important to audit existing water use patterns to identify areas where conservation can be most beneficial. Accordingly, an audit was conducted that included analyses of historical and current water use and evaluation of the meters and billing system that are used to record water use.
Historical monthly water production data from 1989, 1996, and 2002 through 2012 were used to establish baseline historical water use. Historical data indicate that water production is greatest.
during the summer months, with June water production being the highest. Summer water use is greater in all three sectors, but especially in the residential sector, due to outdoor water use and the widespread use of swamp coolers for air conditioning. Evaluation of the largest water users can help to target conservation efforts where they will have the greatest impact. In 2011, the top user was the Ben Altamirano municipal sports complex, which irrigates an area of 11.5 acres. The remaining top users include multiple Western New Mexico University (WNMU) and Silver City Schools facilities, the Gila Regional Medical Center, some apartments and mobile home parks, the Grant County Court House, several commercial customers (e.g., laundry, real estate, lodging, and churches), and Gough Park.
Issues unique to Silver City that affect the goals and design of the conservation program include a large groundwater supply, the need for a revenue-neutral conservation program, the ongoing application for return-flow credit where wastewater discharge is recharging the aquifer, and the sizing of the new solar array at the wastewater treatment plant. Considering these unique issues, the Town of Silver City has outlined the following goals for its water conservation program: reduce outdoor water use, reduce water waste, reduce peak summer demands for more efficient system operation and reduced energy use, reduce pumping and treatment costs, ensure a revenue-neutral program that can be financed by the Town, strengthen ordinances and policies relating to water conservation, minimize nonpoint source pollution by integrating stormwater management into the water conservation program, educate the public about water conservation and sustainable supply issues, incentivize conservation behavior, and prepare for drought contingencies by developing a drought mitigation plan. Performance measures and fiscal impacts are outlined in the plan. The Town anticipates a phased implementation program. Addressing water conservation will not be a one-time event. After the first 5 years of the program, the Town will revisit its longer- term goals. It will be important to continue to carefully monitor water use and assess how uses are changing in response to specific conservation practices. Thus, efficient measurement and reporting will be a key component of the water conservation program.
The water conservation plan is intended to provide a model for discussion with local water associations and the broader regional area of Grant County, including Santa Clara, Bayard, and Hurley, to develop at their discretion water conservation programs and strategies for their own communities. The Town of Silver City provides bulk water to five water associations that operate and maintain their own systems. The information and recommendations in this plan may be helpful to these associations in developing and obtaining their own water conservation goals, but the Town recognizes that the associations are independent and are not bound by the Town’s recommendations.