Currently, the only water meter installed on the WCWD water supply and distribution system is located at the treatment plant. With the entire service area unmetered, the District does not have the ability to:
- Monitor water used as opposed to amount of water treated;
- Detect leaks within the system based on measured flows and comparisons to historical flow readings;
- Monitor water usage seasonally and in periods of critical low flow or extended drought;
- Accurately measure water usage to enable implementation and oversight of conservation programs
- Assist customers in understanding how their irrigation strategies and habits affect overall peak season water consumption and system operation and efficiency; and
- Make every user an invested guardian of the water supply.
As originally conceived, water meters were to be installed in two phases. The first phase would have resulted in installation along the main distribution line at regular intervals, as well as the placement of individual water meters on lateral service connections along Maybert and Relief Hill Roads during installation of related distribution and pressure system improvements (see Maybert Road and Relief Hill Road projects). The second phase of water metering would have resulted in the installation both on the main distribution system and residential service connections within the downtown area of Washington.
Current Status (September 2016)
The System-wide Installation of Water Meters was completed in August 2015. Ongoing use of the meters to detect leaks on both District lines and facilities and customer laterals, will continue through December of 2076 (in conjunction with Project # 13 – Downtown Leak Detection and Repair).
The Nevada City-directed bid process for meter installation within the WCWD system closed in late April 2015 and a winning contractor was identified. Following bid award, the City initiated contract negotiations and also prepared all materials and received all certifications necessary to execute the contract. A pre-construction meeting was held to work out the construction details and a start date of June 1, 2015 was agreed upon. Construction commenced on June 1, 2015 and was completed by the end of July.
As a result of ongoing conferences with the Nevada City Engineer, the WCWD OM, and the construction company, it was determined that the original phasing strategy would not be the most efficient approach. Instead of the original phasing, the pre-construction work included establishing three zones of work: Maybert Road, Relief Hill Road and Downtown and environs. Within these three zones a different basic strategy for installation was identified: For Maybert Road, where 17 services are laid out along the distribution line, the connections were made in a strictly linear order; in the Relief Hill Road area the meters were installed based on which side of the road the connection to the lateral lay, or where the District decided it needed to be; and, in the Downtown area the connections were accomplished based on which lateral connections were already known (done first) and which needed to be located (done opportunistically).
Early in the meter installation process, it became apparent that focusing the leak detection effort solely on the Downtown would result in a variety of existing leaks going undetected and unrepaired. Further, it became clear that many of the lateral connections were already experiencing leaks. As a result, the meter installation effort was paired with Project # 13 – Downtown Leak Detection and Repair and the two projects were implemented simultaneously.
The efficacy of meter installation with respect to leak detection in the District has already been proven. Within one day of installing meters in a portion of the zone along Relief Hill Road, a single leak was discovered by a resident who was reading his newly installed meter. The leak was measured as totaling 1,300 gpd. Upon inspection and interviewing area residents and the property owner, it was determined (anecdotally) that this leak was likely 5 years old (dating from the demolition of an unused structure that had occupied the site). This would mean that with this single leak identification and repair effort, the District stopped a leak that had wasted up to 2,372,500 gallons or roughly 7.2 af of water over a five year period.
If the detected leak on Relief Hill Road is any indicator, the District stands to conserve significant quantities of water by expanding leak detection efforts to include the full distribution system.
In response to this initial detected leak and the repair of dozens of much smaller leaks associated with meter installation, the District has added a component of bi-weekly meter reading through the end of 2016 to determine where leaks are occurring, both in the distribution lines and on lateral lines within customer properties (in support of Project # 13 – Downtown Leak Detection and Repair).
Additionally, the WCWD Board is developing a strategy and accompanying policies to: 1) address issues of conservation related water usage (in response to the 2015 Drought Emergency –related cutbacks of 25%); 2) to establish base line water use for each customer for each month to support future conservation options, and; 3) to determine the role of metered readings in a possible rate study and to support preparation of the Drought Action Plan (Project #14).
City of Nevada City
Bryan McAlister, City Engineer, (530) 265-2496 x126, firstname.lastname@example.org
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