How the Project Operates

The $450 million Los Vaqueros Project, completed at the end of 1997, is the largest capital project in CCWD's history.

The project includes a new intake on Old River near Discovery Bay, 20 miles of buried pipeline, a water transfer facility, a 192-foot-high dam and a 100,000 acre-foot reservoir. It's primary purpose: to assure better water quality and reliability for the District's 500,000 customers.
The Old River Pumping Plant near Discovery Bay
Delta Water
Chloride levels in the reservoir water are at about 25 milligrams per liter (mg/l), much better than what had been projected in the project's filling plan. In summer months or times of drought, when Delta water typically becomes saltier, this good-quality water is used for blending. This keeps chloride levels at the tap at or below 65 mg/l virtually all of the time, a vast improvement over water quality conditions before Los Vaqueros was built.

Filling the Reservoir
Filling of the reservoir began in February, 1998. Because of the huge snowmelt from the previous winter, Delta water quality was at its best since 1995 and remained good throughout 1998. The District took advantage of this by running the new pumps at Old River as much as possible. By December, the reservoir was nearly full -- almost a year ahead of schedule.

Operating Expenses
A substantial operating expense associated with the project is the day-to-day energy costs. To reach the reservoir from Old River, the water must travel through 12 miles of pipeline and be lifted 472 feet. The District conducted an extensive search for a low-cost provider of electricity, eventually contracting with the Modesto Irrigation District to provide a portion of its power. The result was an energy cost savings, to initially fill the reservoir, of another $1.2 million.

Besides managing reservoir operations, CCWD in 1998 adopted a public recreation plan for the 18,500-acre watershed. This was the culmination of a 7 year planning process that involved extensive public outreach.