The Moore Siphon has an interesting history and is a critical piece of infrastructure. Water from the West Adams delivery system north of Cache Creek was needed to irrigate lands south of Cache Creek in the Moore Canal service area east of the city of Woodland. In order to convey this water, a 750-foot siphon, or pipe structure, made of 66-inch diameter corrugated metal pipe, was installed underneath the creek bed in 1982, where it had previously rested on top of the creekbed. When the buried siphon was first installed, the top of the pipe was two to three feet below the creekbed, however, over time natural erosion and the effects of gravel mining lowered the creekbed. This erosion exposed the siphon and subjected it to damage, especially during high winter creek flows. In fact, a forty-foot section of the pipe washed out during the intense 2006 winter season, which was repaired with new corrugated pipe. Another emergency occurred during the 2017 irrigation season when the siphon ruptured and service to water customers needed to be paused while the siphon was being patched up.
It was clear that the time had come for a long-term solution for a siphon replacement. District management embarked on a series of consultations with engineers, geologists and contractors to develop a replacement plan. After all of the surveying, geotechnical analysis, design considerations and meetings with the USACE, DWR and District water customers, it was decided that two new 54” concrete pipes would provide enough capacity for current and future demands. The District took advantage of the opportunity to also upgrade the siphon inlet and outlet structures with remote-operable gates and surveillance cameras.
The patched-up siphon allowed the District to convey water to the Moore Canal during installation of the new pipelines. Construction on the new siphons commenced in May 2019 and the project was ready for to be placed into service the following spring. The new Moore Siphon was built to serve current and future farmers for generations to come.