A project nearly 30 years in the making is one step closer to fruition after Turlock Irrigation District Board of Directors voted unanimously on Tuesday to approve a Water Sales Agreement that aims to provide Tuolumne River water for domestic use to the Stanislaus Regional Water Authority.

“This agreement shows the full measure of TID’s resolve in seeing this project through,” said TID President Ron Macedo. “The project provides numerous benefits to the region while still maintaining the integrity of agriculture within our District.

“We are hopeful SRWA sees the agreement as a positive step forward,” continued Macedo.

The process that ultimately led up to the current Water Sales Agreement began in 1987 when TID initiated discussions with the SRWA, which includes Turlock, Ceres, and South Modesto, regarding a drinking water project that would help offset deteriorating groundwater quality and supplement groundwater supplies by providing a portion of TID’s Tuolumne River surface water.

“Throughout those years, the parties have had numerous discussions, but none of those discussions have materialized to any viable project,” said assistant general manager of Water Resources Tou Her.

While discussions between TID and the cities have been intermittent, the water district constructed an infiltration gallery on the Tuolumne River downstream of the Geer Road Bridge in 2001 to divert river water to a future water treatment plant.  

“That was constructed during the River Restoration Project that we did in that area,” said Her. “So it is there and ready for use.”

Seven years later, TID purchased the water treatment facility site, which is a 49-acre parcel close to the river, and in 2011, the cities of Turlock, Ceres and Modesto formed the SRWA in order to negotiate a water supply agreement with TID.

The Water Sales Agreement that was approved on Tuesday provides terms and conditions under which TID will sell and deliver a maximum of 30,000 acre feet of Tuolumne River surface water, or “Transfer Water,” per year to SRWA.

However, the amount of water that SRWA will receive will be determined by a formula that factors in the amount of TID irrigation water that is made available to growers annually.

In less than normal irrigation years, or years when irrigation customers are given less than a 48 inch water allotment, SRWA will have to provide “Offset Water” to TID, which would be a combination of recycled water and non-potable, or undrinkable, well water.

Included in the amount of “Offset Water” is 2,000 acre-feet of “baseline recycled water,” an amount that was approved during the Turlock City Council meeting on Tuesday. The amount is to be provided by the City of Turlock on behalf of the SRWA every year regardless of whether it is a normal or dry year.

This “Offset Water” will be used to balance the reduced Tuolumne River water available to TID irrigators resulting from the transfer of surface water to SRWA.

“This water does not meet drinking quality water standards,” said Her. “However, it meets water standards that are sufficient for ag use.”

Her provided an example using a water year where irrigation customers are only given 36 inches of water, or a 25 percent reduction from a normal irrigation year that provides a 48 inch water allotment. 

As a result, TID would only be responsible to provide 22,500 acre feet of “Transfer Water” to SRWA and SRWA is responsible for providing 11,250 acre feet of “Offset Water” to TID.

The 50-year agreement is limited to a maximum of 30,000 acre-feet of Transfer Water to SRWA per year and SRWA would be charged according to TID’s Tier 4 Irrigation Water rate, which is currently $20 per acre foot.

The agreement would also allow SRWA to carry out several actions that would ultimately allow the coalition to construct and operate a water treatment plant to service the three cities with domestic water.

According to TID, the overall project would provide a number of benefits, including assisting SRWA cities to better meet water demands, providing in-lieu groundwater recharge for agriculture and urban users, and providing additional fishery and aquatic benefits to the Tuolumne River.

Additionally, TID—which will obtain access to recycled water— and SRWA cities—which will have access to surface water—will be effectively able to diversify their water supply portfolios.

After having garnered the approval of the TID Board of Directors, the agreement will now be presented to SRWA for consideration. Any final agreement would still need to be formally approved by TID and SRWA boards.

“If it is approved by SRWA, then this agreement is the first step and the significant step towards the eventuality of the project itself,” said Her.

In attendance during Tuesday’s TID Board meeting was City of Turlock Mayor Gary Soiseth, who revealed his intention to call a special meeting with the SRWA on Thursday to discuss the agreement and take potential action.

“This is a huge step forward for water reliability for the entire region, including Turlock,” said Soiseth.