With below average rainfall expected for the next three months, Santa Barbara County remains in a severe drought, the Santa Barbara City Council announced during its Water Supply Management Report meeting on Jan. 30.
The Gibraltar Reservoir, located on the Santa Ynez River, received only 31 percent of what is considered to be a normal amount of rainfall for this time. The Cachuma Reservoir received only 42 percent of the typical amount, and Santa Barbara County altogether received 25 percent of normal rainfall.
In addition to decreased rainfall, the report showed impacts on water quality in the reservoir due to the fires. Due to the most recent rain event on Jan. 9, the reservoir received 500 acre-feet of inflow. It is unknown how much of this inflow was composed of ash or mud.
According to Kelley Dyer, water supply manager for the City of Santa Barbara, the inflow to the reservoir can be treated, but it takes about three weeks for the sediment, including ash and mud, to settle out, so the county has been pulling from other sources.
The impact of the Thomas, Whittier and Rey Fires on water quality and supply of the Cachuma, Gibraltar, and State water supply “will last for years,” Dyer said.
This year “has been one of the driest on record, just a bit better than the 2014-2015 year,” which was the worst to date, Santa Barbara City Councilmember Eric Friedman said during the meeting.
“We’re taking this seriously and looking ahead … We were one of two counties that were not out of the drought last year while the rest of the state was,” he added.
The report showed the impact of rainfall from Sep. 1, 2017, to Jan. 29, 2018 in Santa Barbara, as well as the county’s two main sources for water supply.
“Rainfall, as you may expect, is very low,” said Joshua Haggmark, a water resources manager for the City of Santa Barbara.
Due to the recent fires and lack of rain, the water supply is diminished from previous years.
This is a significant change from the report of rainfall during this time last year.
From Dec. 10, 2016, to Jan. 23, 2017, the impact of of rainfall was much higher in Santa Barbara County and its sources of water. The Gibraltar Reservoir received 133 percent of the expected amount of rainfall, and the Cachuma Reservoir received 147 percent of normal rainfall. Santa Barbara County received 163 percent of typical rainfall for that time of year.
Dyer explained that when the Cachuma Reservoir stops spilling is when it is clear that Santa Barbara County is entering a drought. A reservoir “spills” when it has reached higher than 100 percent capacity, so the excess water goes through a spillway connecting to the local creeks and waterways.
She said that the last time Cachuma spilled was in 2011.
A drought was declared in Santa Barbara County in 2014, with drought conditions growing worse since then, according to the City Council report.
The council predicts the water shortage to extend into 2020, according to a diagram shown during the meeting.