A 65-mile long canal connects water to farmers, growers and residents in the Glenn-Colusa Irrigation District (GCID). The largest irrigation district in the Sacramento Valley, it encompasses 175,0000 acres, of which 140,000 of those acres are farmed. Getting water to users is crucial in these parts. Over 800 miles of additional canals, laterals and drains are wrapped around the main canal system.
For over 40 years, Pat Kennedy, Water Operations Superintendent for GCID, has assisted in developing this water delivery system. On the eve of his retirement he gave us an inside look at how and why technology has changed water management in this vital part of our valley.
How is water managed?
It’s all about elevation. Maintaining a certain water elevation level in the canal is key to our water management. Our system is 99 percent gravity flow so any water that’s in our canal is gravity fed into the surrounding fields, so elevation is critical because the water elevation in the canal has to be kept at a steady elevation in order to move the water through the system and meet the irrigation demands at all locations.
Every water operator takes orders from their grower and they convey those to their supervisors, who compile it all and make an order to the pump station everyday. Daily water orders are made from the field level all the way up to the pump station for how much to turn on at the pumps. In order for everyone to get the water they need, the system has to be run very efficiently
Check structures are key. Why?
Within the 65 miles of main canal there’s a series of check structures that control the elevation of each pool. Years ago they were boards that had to be manually moved in and out of the check structure to control and move water down stream.
Prior to automation, we had to have people running up and down the canal constantly adjusting all these checks. We never knew what the elevation was once we left, it changes constantly.
Elevation is still key but managing it is now high tech. Explain.
Is has changed in that water operators would go out and manually move boards versus now a gated system where a lot of it is done remotely, via computers and programming through SCADA (Supervisory Control and Data Acquisition). We started to automate our system in 2010 and it took 2 1/2 years.
Now with the automation you plug in a target, a target meaning an elevation and that is that elevation is sea level; you plug that target in and your check structures and radial gate, automatically go up and down ever so slightly and they maintain that same elevation, that desired elevation, 24-7.
Thousands of alarms are built within the SCADA system. You can turn on your computer in the morning and there are so many alarms lit up like a looks like a Christmas tree. For example, perhaps the SCADA system calls for a gate to open up, and something else fails, it will actually call out to the operator over the phone saying this gate won’t move.
We have literally hundreds of sensors. Most of our sensors are in places that allow us to conserve as much water as possible. Our SCADA system can be seen from all supervisors’ desktops at home, their phone, everything else. Additionally, there are level sensors that tell you the level sensor failed, and your elevation isn’t what you think it is. Then you have to get in your car and go for a ride.
How has technology changed water management?
There is no comparison to what it used to be. From a conservation standpoint we can maintain the same flow going down the lateral system as well as the field delivery system. Farmers have the same flow, day after day after day, rather than prior to SCADA, there was no way you could manually operate a system and keep it in the range that SCADA keeps it in elevation wise.
We have over a thousand water users and, to make sure that everybody gets the water they need, it has to move through the system efficiently and be regulated.