Upgrading The Flow Measurement System At The Tehama Colusa Canal Authority

The Tehama Colusa Canal Authority (TCCA)’s mission statement is: “. . to secure, protect,
and develop dependable and affordable sources of water and to operate, maintain, and
improve the works essential to deliver such water.” Operating two canal systems for the
USBR (the Tehama Colusa Canal, 110 miles long and the Corning Canal, 15 miles long), the
combined system serves 17 water districts. For many years the system relied on gravity-fed
Sacramento River water from releases at the dam at Red Bluff. However, because of
regulations implemented in the late 90’s, the USBR could no longer rely solely on these
releases and so installed four pumps with a total capacity of about 400 cfs. With peak
irrigation demand between 800 and 1000 cfs, some creative hydraulics had to be
implemented to assure uninterrupted delivery.
The solution involved installing an automated control system with both upstream and
downstream control. Target elevations are maintained both upstream and downstream of the
gates on any given pool. The resulting system is fairly stable and flows can reach 1700 cfs
over the 110 mile stretch meeting the needs of the various districts. However, because the
system no longer relies solely on gravity, complex flow conditions with reversals and
stratification became the norm which required an evaluation of new discharge metering
technologies that could work accurately under these conditions.   Read more on this.