Sycamore Slough Solar Project

solarIn 2009 Reclamation District No. 108 completed construction of a 386KW DC solar generation facility that produces enough energy to power 110 California homes.

Energy is a significant operating expense for RD 108.  Water and recycled water enters and leaves the District through the pumping facilities along the Sacramento River.  The District is very efficient in its water use and operates an extensive water recycling system that encompasses four pumping plants that recycle approximately 50,000 acre-feet annually with Sycamore Slough being the largest.  Water draining from the fields is captured in the system and reapplied to the fields for irrigation.

The solar generation facility sits on seven acres adjacent to the Sycamore Slough Pump Station.  The panels operate on a dual axis tracking system to follow the sun as it moves throughout the day to optimize energy production.  The tracking system is also designed to meet minimum flood requirements by raising the solar panels 15 feet in the event of a flood.

Energy SavingsSolar_2

The potential for cost savings first attracted the District to the solar project.  As energy prices continue to rise, the solar facility provides affordable renewable energy for today and years to come.  The money savings are passed along to the farmers in the District.

The project is part of a net energy metering program that allows the District to balance energy production and usage on an annual basis.  PG&E calculates the amount of energy the District consumed and credits the District with the total amount of energy produced at the solar facility.  At the end of the year, the District will only pay the difference from the amount of energy used and amount of energy produced.

The total project cost was $3.4 million, not including a $1.5 million rebate the District received for PG&E.  The exact cost savings from the project will fluctuate with PG&E’s changing rates, but the District calculated that when the PG&E rates increase by 2.5 percent annually, the project will result in a 10 percent savings.

Clean Energy

The solar generation facility produces clean renewable energy that reduces impacts to the environment.  The solar facility continues the Reclamation District No. 108 commitment to serve its water users in a reliable, economic and environmentally sound manner.

Long Crested Weir

Long Crested Weir 3Distribution canals in the Eastern area of the District are concrete lined with low volumes and high velocities, making them difficult to manage with flash board check structures.  Prior to the project, approximately 10 cubic-feet per second of additional flow was required throughout the irrigation season in order to ensurer sufficient flows were delivered to the farm turnout.

Previously, an adjustable flash board structure was located slightly downstream of each farm turnout.  In order to maintain a stable canal water surface elevation, every time the flow in the canal was Long Crested Weir 2changed, boards were added or removed.  The benefit to installing Long Crested Weirs in place of adjustable flash board structures is that for cost fluctuations in canal flow rate, the change in water surface elevation at the turnout remains nearly constant.  This provides a constant flow to the irrigated field.  It also substantially reduces labor and the chance of human error.

The same characteristic of the Long Crested Weir that makes it useful in canals for water level control eliminates the weir as a measurement device.  Therefore, the District was required to add measurement methods at key locations throughout the conveyance system.

Long Crested Weir 1

Fishscreen Program

Reclamation District No. 108 diverts irrigation water from the Sacramento River.  In order to protect the fish populations in the Sacramento River, RD 108 was one of the first irrigation districts to invest and install a fish screen on its primary river diversions.

Wilkins Slough Pumping Plant and Fish Screen

The Wilkins Slough Positive Barrier Fish Screen culminates nearly 8 years of planning, agency coordination, testing alternative barriers, feasibility study, design and construction.  The Wilkins Slough Positive Barrier Fish Screen was put into operation in March 1999 at the start of the irrigation season.

The objectives of the project were to make the Wilkins Slough Diversion “fish friendly,” minimize the impact of water diversions on winter-run chinook salmon and meet current resource agency criteria for fish protection facilities.  A critical goal that was successfully met was to construct the fish screen structure without interrupting irrigation water deliveries or interfering with fish migrations in the Sacramento River.

Wilkins Slough Positive Barrier Fish Screen is one of the largest fish screening facilities in the Sacramento River Basin.  The facility has a design flow capacity of 700 cubic feet per second but can accommodate flows up to 830 cubic feet per second.  The structure is positioned along the right bank of the Sacramento River in front of the Wilkins Slough forebay.  The screens are continuously cleaned by a single-arm mechanical brush mechanism that sweeps across the entire screen surface every 5 minutes.

Emery Poundstone Pumping Plantpoundstone_pp

Reclamation District No. 108 consolidated three of its river diversion pumping plants into a single facility with a state-of-the-art fish screen.  The initial project investigation confirmed that it would be less costly to build a new combined pumping plant with a fish screen than to install separate fish screens on each of the three existing pumping plants.  Further, it was determined that combining the three pumping plants would result in a lower water diversion requirement, thereby lessening the effects on protected fish species.