We are writing this letter to make clear our position respecting the current controversy over water resource planning by the Los Osos Community Services District (CSD).
The fundamentals of our water crisis do not require either great expertise or significant insight. The following are the relevant facts.
The community, now roughly 14,000 souls, is entirely dependent on the aquifer underlying Los Osos. That aquifer is bounded on the west by the Pacific Ocean, the Irish Hills to the southwest, and high hills on the northeast. It is asserted to be a single basin extending roughly to the new sewer plant (or, based on various historic studies and well logs, its eastern extremity may end roughly at South Bay Boulevard). The two perceptions may drive certain legal challenges to the current Los Osos basin management plan but are not the principal focus of this letter.
The county's goal is to allow further development and a 5,000-person expansion of the community, dependent on this same aquifer.
Any reasonable reading of the basin plan evidences its failure to take into account basic high school physics.
Basin water management includes severe restrictions on domestic water consumption, restricting household use sufficiently to cause prospective purchasers to be hesitant to buy properties in the basin, and making modest outdoor landscaping difficult. The proposal to add another one-third to the user population without significantly improved water resources is absurd.
Most severely, even with such restrictions, the top of the freshwater aquifer has already fallen below sea level. Ocean salt water is heavier than fresh water, which guarantees the movement of seawater into the western side of the Los Osos aquifer, and it is continuing as you read this letter. Once this contamination occurs, it is very difficult to reverse. Thus, water management that increases seawater intrusion represents a nearly criminal failure.
Curiously, earlier drafts of the Basin Management Plan dismissed efforts to increase the amount of fresh water from other sources. County advocates claim that reinjection of treated sewage water will increase the basin resource, but that water only replaces what's no longer injected by individual septic systems. It does not increase the resource.
No "studies," or pumping adjustments among the public water wells, could possibly stop the current seawater intrusion, which is assured by having a freshwater aquifer level below that of the adjacent Pacific Ocean. The use of such "studies" or occasional "results" to persuade the community that the severe long-term problems can be solved without finding additional freshwater resources is a serious misrepresentation. No understanding of basic physics would support such representations.
We have been told that the movement of public wells further east would "solve" this problem. That is both "true," and a misrepresentation. It would solve the short-term problem, as those wells would escape the immediate saline contamination. But that would absolutely not stop the rate of seawater intrusion into the basin, which, as noted earlier, represents the potential for irreversible damage to the aquifer
There is a second and also severe problem with moving the wells farther east. If there is not one, but two or three basins as one moves east (and earlier geologic studies, as well as agricultural and private well logs make it appear that is the case), the drilling of new wells farther east by the public water companies is illegal.
A cost-effective solution
None of the goals of the basin management plan will succeed without additional freshwater resources. The proposal to add 5,000 residents to a desperately decaying freshwater aquifer is ridiculous.
However, robust additional freshwater resources are available in the form of stormwater recapture. There are two separate resources for stormwater recapture; one from the Irish Hills (Los Osos Creek), and the other from the Warden Lake watershed. Both can easily provide stormwater capture.
In terms of volumes available, Warden Lake, which drains roughly 4,800 acres, will in a normal year, receive 6,840 acre-feet of rain. For comparison, at the rate of 50 gallons per day per person in Los Osos, the aggregate annual domestic consumption is 887 acre-feet.
Although there are losses from upstream consumption and evaporation, there is an enormous amount of additional fresh water available for recovery from this resource, easily enough to double or triple the current domestic consumption while solving the problem of seawater intrusion permanently.
There are many simple models for capturing stormwater runoff at Warden Lake, though over the last 15 or more years, nothing appears to have been done to examine this—one of the very few, if not the only, opportunities to deal with this crucial issue.
This crisis is severely underestimated, and a lack of attention to the threat of destroying the Los Osos aquifer by seawater intrusion (as well as the continuing impairment of local real property values), is a serious failure of the CSD to meet its public obligations.
We are committed to doing whatever we can to enhance the Los Osos aquifer. The capture of local stormwater runoff would meet the county's goals of securing the long-term freshwater resources of the town, avoid destruction of our precious aquifer, and enable the return to a prosperous real estate market.
The failure to take such actions will leave the community with more severe water rationing, and the potential of requiring a seawater desalinization plant, with its massive capital costs and very expensive domestic water.
The failure to address these matters is unacceptable. Δ
The Los Osos Groundwater Committee is made up of 10 farmers who reside in the Los Osos area, including Barry Branin. Send comments through the editor at email@example.com write a letter for publication and email it to