Development of a water conservation plan for the Town of Buena Vista, Colorado

A professional project report submitted in partial fulfillment of the requirements for the degree of Master of Water Resources, Water Resources Program, University of New Mexico.The Town of Buena Vista (Town) has a limited water supply, although Cottonwood Creek runs through the center of Town and the Arkansas River borders the Town to the east. The Town’s water rights portfolio is entirely on Cottonwood Creek, and includes a reliable 10 cubic feet per second (cfs), or 6.46 million gallons per day (MGD) for the months of October to March, but only 3.88 cfs (2.51 MGD) senior water rights from April to September, which coincides with irrigation season. The Town does not own any water rights on the Arkansas River. The existing treatment and distribution capacity for the Town is approximately 2.15 MGD. The maximum daily demand in 2011 was 1.421 MGD, which is equivalent to 56% of total available water rights, and 66% of treatment capacity. Using a 3% growth rate, the Town will increase in size by 55% in 20 years or less, and there will be an insufficiency of water rights and of supply capacity to satisfy demands. In order to prevent a future shortage in the water system, a water conservation plan was approved by the Board of Trustees for commencement. The water conservation plan was developed following Colorado Water Conservation Board (CWCB) guidelines, and is intended to be adopted by the Board of Trustees and approved by the CWCB in order to be eligible for grants for water conservation implementation projects. The twenty-year forecast for maximum day demand exceeds the existing supply capacity by 367,000 gallons a day, and exceeds the existing irrigation season water rights by 10,000 gallons per day. Prior to conservation, the ratios of demand to supply capacity and demand to water rights are 1.17 and 1.0, respectively. The Town’s Capital Improvement Plan contains $6M of production-related improvements between 2012 and 2018, including: install well #3; install additional storage tank; install non-potable Arkansas River well #4; increase water treatment plant capacity; and purchase additional senior water rights. If all of the proposed projects were installed, the monthly rate for water system customers would increase over nine dollars, or 34%. Conservation measures were analyzed for implementation in order to reduce the need for the expensive projects proposed to meet growing demands, with the following goals: reduce the water loss rate from 26% to a more typical rate of 10-15%; reduce irrigation use to decrease peak use in the summer which coincides with the period when the Town has significantly less water rights; and reduce indoor use at residences, which comprise 81% of the water system customers. More than eleven specific measures for conservation were considered per Colorado Revised Statutes (CRS) 37-60-126. The measures were screened for applicability, success rates in other municipalities, costs, and benefits, and the following measures were combined and recommended for implementation: 1. Toilet and/or showerhead and faucet rebate programs; 2. Education/audits (public education, water-saving demonstrations); 3. Conservation (tiered) rate structure to encourage efficiency; 4. Leak detection system purchase; 5. Regulations/Ordinances regarding landscape efficiency (low water use landscapes, drought-resistant vegetation, and watering restrictions); 6. Regulations/Ordinances prohibiting once-through cooling for industrial and commercial efficiency. The implementation of the combination of measures will achieve the goals of reducing loss, irrigation use, and indoor use, with an estimated savings of 9.1 million gallons of water annually at a projected cost to the Town of approximately $13,000 per year. A one-time purchase of a $10,000 leak detection system could provide an additional 600,000 gallons per year savings. The decrease in maximum day demand after implementation of the proposed conservation measures is estimated to be over 392,000 gallons, a 16% reduction. The Town should install one proposed infrastructure project to provide a safety net for the supply system since the demand to supply capacity supply ratio is 1.0 after conservation. If non-potable well #4 on the Arkansas River was installed the Town would achieve diversification of the water rights portfolio, given that all the other Town-owned water rights are on Cottonwood Creek. Alternatively, the Town may wish to install well #3 to provide redundancy to the system and decrease the burden on the lift station. The addition of either well would suffice to provide a safety net in the supply capacity projections, and protect the Town against unexpected fluctuations in peak use by decreasing the ratio of demand to supply capacity of 0.9. The forecast for supply capacity and demand assumes that the conservation measures are implemented immediately in order to see expected results. The costs to the Town should be negligible or nonexistent if grants are awarded to implement the conservation measures, and operation and maintenance costs are decreased due to less water needing treatment. The customers would benefit from the conservation programs by receiving a reduction in annual water bills of nearly $100 if the customers participate in all the measures