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Northridge Water District (NWD), located in the north central part
of Sacramento County, in Sacramento, California, along with several
other area water agencies faced the similar issue of finding an
adequate water supply for a growing population through conjunctive
use of surface and ground water.
Northridge draws on 33 wells in its district to supply 19,145 customers
of which 17,238 are residential. Over the past 20 years, the ground
water table has been overdrafted at a rate of 1.5 to 2 feet per
year. The lower water table deteriorated the water quality as well
as increased the energy costs for pumping. In addition, state and
federal environmental agencies are instituting new water quality
standards that would require further expenditures for the 33 wells.
The District has historically relied solely upon groundwater, however,
Northridge has been trying for 20 years to get access to surface
water. To pursue a jointly built pipeline would offer many advantages
such as combined engineering design, environmental studies, bond
sales, pipeline construction, etc.
 In
December of 1993, Northridge partnered with the San Juan Water Group
to build a project known as the Cooperative Transmission Pipeline.
The project allows more water to flow from Granite Bay into the
North Sacramento area, and the pipeline can be tapped along the
way as necessary. A water treatment plant on Folsom Lake would supply
water to Northridge through a joint water agencies pipeline. Northridge
would then complete an 8.5-mile conveyance pipeline along Antelope
Road for its portion of the joint project.
In the spring of 1994, Northridge sought bids for supplying 8,275
ft. of 48-inch pipe due to the County of Sacramento widening Antelope
Road. A supply bid was taken because of the critical completion
schedule for the road widening. Ameron International was awarded
the contract to supply 48-inch AWWA Standard C303, Concrete Pressure
Pipe, Bar-Wrapped, Steel Cylinder Type in 40-foot laying lengths.
After the completion of the road-widening project, Northridge negotiated
with Ameron for the supply of 6,275 ft. of 48-inch Concrete Pressure
Pipe on Schedule A of the conveyance pipeline. The district required
that this portion be installed in the winter to reduce construction
impact on the residential area. Pipe laying in predominately city
streets complicated the project's public relations.
While Schedule A was being completed, Ameron and Northridge again
negotiated for the balance of the conveyance pipeline, Schedules
B through F. Northridge awarded the supply contract in December
of 1995 for 25,950 ft. of 48-inch, 725 ft. of 36inch, and 3,975
ft. of 30-inch Concrete Pressure Pipe. The relationship that developed
between Ameron and Northridge was evident by the trust in working
together to complete the final portion of the conveyance pipeline.
Schedules B through F involved many demanding tasks such as an
800 feet long bore under Interstate 80, a major interstate highway
connecting California and Nevada, and 125 feet long bore under a
primary Southern Pacific Railroad line. Also, those schedules required
multiple installation crews in order to meet the anticipated completion
date. Portions of the 48-inch pipe were installed in quite residential
streets therefore requiring minimal disturbance for the citizens.
Boyle Engineering was the design engineer for the conveyance pipeline
as well as the joint water agencies pipeline. T & S Construction
of Sacramento was the installation contractor on the entire water
conveyance pipeline. Ameron International supplied 45,200 ft. of
48, 36, and 30-inch Concrete Pressure Pipe for Northridge's pipeline.
Each agency could have approached its problems individually. It
was working together that succeeded in providing an upgraded water
supply to a growing population. The pipeline also allows Northridge
to participate in the conjunctive use program of Sacramento County,
which is designed to stabilize ground water overdraft in the area
by the year 2000. Northridge Water District has sought and attained
the best possible water available for their customers. This was
truly an investment for their future.
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