Emerging from a wet winter, state water officials were able to set aside 50,000 acre-feet of water for the Santa Clarita Valley’s water wholesaler, the Castaic Lake Water Agency.
How much water is that? It’s about 50,000 football fields each under one foot of water.
This water earmarked for CLWA use is called “carryover” water.
Unlike managing water in a drought year, when every drop of water is used, the agency couldn’t use its 50,000 acre-feet of “carryover” water in this current wet year.
Consequently, about 35,000 acre-feet of water earmarked for the CLWA went unused.
State officials then took that unused water – called spilled water – and poured it back into their “pool of water” resources, making it available to all agencies contracted with the state to receive State Water Project water.
The unused water doesn’t get wasted, it just stops being water earmarked specifically for the CLWA.
“Regarding the spilled water, effectively 35,000 acre-feet of water was spilled,” Dirk Marks, the agency’s water resources manager, told The Signal Tuesday.
“That doesn’t impact our overall reliability as we have more than enough water to meet this year’s demands and still into carryover for possible use in 2018,” he said.
On Wednesday, members of the CLWA board will get a report prepared by Marks, explaining how water resources are managed during a wet year.
Here’s how it works:
The CLWA is the Santa Clarita Valley’s water wholesaler. It is one of 29 State Water Project contractors entitled to receive water from the Sierra Nevadas in Northern California.
Every year state officials with the Department of Water Resources assess the Sierra Nevada snowpack, calculate how much water the melted snow will produce and allocate how much each of the 29 agencies should get.
The CLWA is entitled to 95,200 acre-feet of water. It gets only a percentage of this allocation, however, depending on how dry the current year is.
Like old western movies depicting cowboys stranded in the desert with just one canteen, one person rations – or allocates – how much each cowboy receives.
“DWR’s allocation varies year to year depending on the hydrologic conditions and reservoir storage etc.,” Marks explained to the Signal Tuesday.
“Very dry-years like 2014 we received five percent of our (allotted) amount. In 2016, with average precipitation we received 60 percent.
“Our water supply contracts also provide the ability to carryover water from one year’s allocation to another if storage space is available in DWR conservation reservoirs such as San Luis Reservoir,” Marks said.
At the height of the four-year drought, the San Luis Reservoir looked like an empty swimming pool. Last month, it was brimming to capacity.
“However, if DWR has the ability to pump enough water out of the (San Joaquin) Delta so that it needs to use the storage space occupied by carryover water in San Luis Reservoir, that carryover water effectively ‘spills’ that is to say lost to the contractor’s that placed their water into carryover storage,” Marks said.
That’s what happened this year, when 2017 turned out to be a “very wet year,” Marks aid.
By mid-February the contractors’ carryover water was being displaced with the state’s 2017 water supplies, meaning state officials wanting to put their saved water into the reservoir found no room there because of the carryover water was stored there.
The end result, since CLWA was only able to use some 15,000 gallons of water of the 50,000 it set aside, it came up with a plan to use the remaining 15,000 gallons.
CLWA staffers came up with a plan to use as much of the “carryover” water as they could, because essentially – water in the bank is like an operational budget, if you don’t use it, you lose it.
“To minimize the quantity of CLWA water being spilled, CLWA took several actions,” Marks said. “We asked the retail purveyors to increase takes of imported water and back off of groundwater pumping.”
The three main water purveyors in the Santa Clarita Valley are: the Newhall County Water District, the Valencia Water Company and the Santa Clarita Water Division.
“We were able to use about 3,000 acre-feet of carryover (water),” Marks said.
The second part of the plan was called “an unbalanced exchange agreement” and it involved the Metropolitan Water District of Southern California. It is a cooperative of 26 cities and water agencies, Santa Clarita and CLWA not being one of them.
“Because of its larger demand, MWDSC was able to take a portion of our carryover water into its service much more quickly that we could have,” Marks said.
“So, for every three acre-feet they were provided, we were able to take in exchange two acre-feet of (State Water Project water) from MWDSC.
“The result is CLWA was able to use 12,000 acre-feet of water that we otherwise would have lost,” Marks said.
on Twitter @jamesarthurholt