Yesterday the Casitas Municipal Water District‘s management staff and Board of Directors held a meeting and heard a “Preliminary Water Security Project Analysis” report from two consultants, including hydrogeologist Jordan Kear, who has been surveying the Ojai Valley for years for a groundwater agency, and knows its geology well. (Note: the project analysis is attached to the agenda for the meeting at the bottom of the doc).
Let me just cut to the chase: Kear identified a large geological formation called the Matilija Sandstone that contains — history indicates and the geology verifies — a substantial amount of water.
A band of sandstone runs through the coastal mountains behind Santa Barbara all the way south to the mountains behind Lake Casitas. Drilling long tunnels (or “adits”) into the rock could allow the district to recover water stored in the porous rock over eons without pumping.
Here’s a slide from the presentation. Follow Santa Ana Creek north (up) and you’ll see it almost meets the planned 10,000 foot “Central Hobo” bore line. “HoBos” stands for horizontal bores.
Kear estimates that the formation, which in this area is about six miles long and 2,000 feet deep, at an elevation of about 3000 feet, contains a minimum of 29,000 acre feet of decent quality mountain water, by a conservative estimate, or as much as 216,000 acre feet of water, by a liberal estimate.
That’s more water that can be stored in Lake Casitas, possibly.
The idea is that the formation will serve as a backup bank for the lake, to be called on in times of drought. The formation does recharge, Kear estimates, at 2,000 acre-feet a year on average, so if the district calls on the bank when in drought, and the formation is what it is estimated to be, that would give the water district access to a large amount of water at a reasonable price — $5.6 million per bore, or less than a $1000 per acre-foot.
Which is a bargain. The city of Ventura has estimated that state water, if available, will cost about $2000 an acre foot, and desalinated water would cost about $2400 an acre-foot, according to board member Bill Hicks.
In his presentation, Kear noted that when Santa Barbara authorities drilled into the same sandstone formation back in the 1950’s to construct the Tecolote Tunnel, they saw “an increase in flow from about 1,000 gallons per minute, to 7000 gallons per minute.” Kear believes that tunnel is an excellent proxy for the proposed HoBos.
The Board approved further investigation of the project by a unanimous vote (although it did not close the door on an “intertie” to the State Water Project with the City of Ventura, which is already working on such a plan).
After the vote, Board Member Russ Baggerly declared “This is exciting!”
A possible solution to drought-caused water panic for one community in Southern California? Yes — exciting is a fair description. Shocking might be another word.