As a boy, I remember hearing the Sons of the Pioneers sing:
All day I've faced a barren waste
Without the taste of water, cool water
Old Dan and I with throats burned dry
And souls that cry for water
Cool, clear, water
I was reminded of this song when I attended the Visalia City Council Strategic Planning Workshop on February 4, 5, 2011. A report on Visalia’s water supply was presented there by Kim Loeb, Visalia’s Natural Resource Conservation Manager, and Mark Larsen of the Kaweah Delta Water Conservation District. The following are excerpts from that report.
Visalia’s water supply is obtained solely from ground water that is primarily purveyed by California Water Service Company (Cal Water). Ground water beneath Visalia occurs in the Kaweah Basin, which is part of an inter-connected aquifer system that extends across much of the San Joaquin Valley. In the Kaweah Basin, agricultural pumping accounts for about 90% of the groundwater used.
The depth to water in Visalia averaged less than 20 ft. below the ground until about 1960; averaged between 20 ft. - 40 ft.from 1960 to 1990; declined precipitously to about 75 ft. by 2000; and dropped down to an average of 115 ft. below the ground in 2010. By December 2010, the depth came back up to 110 ft., most likely due to groundwater recharge efforts.
During the 1990's, the average decline in our Visalia groundwater table was 3 feet per year. In the 2000's that increased to 4 feet per year.
Cal Water’s annual pumping has increased about 233% from approximately 15,000 acre ft. in 1980 to about 35,000 acre ft. presently. Cal Water estimates that it can pump 23,500 acre feet per year without contributing to the overdraft. Cal Water pumping has exceeded the estimated sustainable amount since 1995; however, regional overdraft has a significant impact on water levels beneath Visalia, irrespective of Cal Water’s pumping. As surface waters become less available for farming purposes, mainly due to environmental issues, more groundwater is pumped, adding to the decline of Visalia’s water table. Likewise, as Visalia’s population continues to grow, more water usage is anticipated. The majority of the city’s water is used for landscape irrigation.
The City is at the forefront of efforts to address this water overdraft issue. Visalia has an ongoing groundwater recharge program. When funding is available and prices are reasonable, the City purchases surface water on the spot market to recharge groundwater. The water is run through waterways or placed in basins to percolate into the ground and recharge the aquifer. Over the last five years, the City has recharged an average of 2,800 acre ft. per year. In 2010, the City purchased and recharged over 7,800 acre ft.
Visalia’s current water conservation plant upgrade will enable the City to recycle 100% of our wastewater. Some of the recycled water will be used to irrigate facilities on the west side of the city, but plans are to trade the majority of the recycled water with farm irrigation users west of the City in exchange for surface water that can be used for recharge on the east side of the city. Approximately 14,500 acre ft. of recycled water will be generated annually by the upgraded water conservation plant, and as much as 24,500 acre ft. may be generated by 2025.
Additionally, plans are to construct infrastructure to deliver recycled water from the wastewater treatment plant to irrigate Plaza Park, Valley Oaks Golf Course, and the Visalia Municipal Airport so that irrigation wells at these facilities can be turned off. The system can be expanded to support new development on the west side of the City.
Of course, water conservation by our citizens can directly improve the City’s water supplies. While analysis suggests that less than half the water artificially recharged may provide a direct benefit to the City (although it does to the region) water conservation provides a one-to-one direct benefit. An acre foot not pumped is an acre foot saved.
Visalia, and the region, is on an unsustainable course. At this rate, wells will continue to go dry, requiring expensive, deeper drilling. The City must do its part to reduce its increasing water demand and to increase supply. The General Plan update will address these concerns further. Long-term regional solutions are also required as more than 90% of groundwater use in the Kaweah Basin occurs outside of the City.
If you have questions or topics regarding the city which you would like to have addressed in future articles, please email Warren at wgubler@ci.visalia.ca.us, or call (559) 713-4400 x 3313.
