Opinion: Water from Devil’s Slide for MWSD: What are the facts?


Posted by on Fri, June 27, 2008

Paul Perkovic is Board President of the Montara Water and Sanitary District (MWSD), however this article reflects his individual views and does not indicate a position of the District.

There has been discussion in the community about whether MWSD should use water from the Devil’s Slide project. This article summarizes what is being said, what is known, and what can be concluded. It is not intended to advocate for any particular solution, just to present facts and background information.


  • Far less Devil’s Slide Tunnel water is available than claimed
  • Its reliability is not yet proven
  • Construction costs could be $175,000 per acre-foot or more for pipelines and treatment
  • Proven alternatives can be built at approximately $10,000 per acre-foot
  • Recycling water may provide new water, cost savings and environmental benefits for Montara / Moss Beach citizens
  • MWSD’s new Alta Vista Well may solve much of the existing water supply deficit

What is being claimed

Jim Larimer, an elected Director of the Coastside County Water District (CCWD), writes on TalkAbout, "Ask MWSD why they did not attempt to get the 1,000 gallons per minute of water that is coming out the Tunnel Project?" in one of his postings.

Charlie Gardner, an elected Member of the Governing Board of Cabrillo Unified School District, echoed that same question here on Coastsider, asking: "The tunnel project my company is currently constructing has enough water coming out of the mountain to relieve the moratorium. What has MWSD done to make that available?"

What are some of the facts?

Charlie Gardner provided prompt, informative answers to the questions I posed. It is remarkable what can happen when we work together towards solutions, rather than attacking each other. Jim Larimer, on the other hand, continues to defend his recklessly irresponsible claim of 1,000 gallons per minute, and refuses to answer any questions about his own district.

Charlie Gardner is a civil engineering construction Project Manager with Kiewit Pacific Company, which is building the tunnel, so he may have access to relatively reliable information.

Mr. Gardner reports that the "current yield of dewatering from the tunnel is in the range of 25-50 gallons per minute." That is a far cry from the 1000 gallons per minute being tossed around on TalkAbout as "truth" by Jim Larimer.

A yield of 25 to 50 gallons per minute (gpm) is equivalent to about 40 to 80 acre-feet of water, a common measure in the water utility industry.

Construction cost estimates

Mr. Gardner suggested very rough cost estimates of $1 million for a treatment plant to bring this water up to public drinking water standards, $3 million for a pipeline, and $3 million for other costs. This gives a total estimate of $7 million, or a capital cost of $87,500 to $175,000 per acre-foot, if we accept Mr. Gardner’s estimates as realistic.

I sincerely thank Mr. Gardner for his answers and spirit of cooperation. It confirms that the MWSD Board already has better options in hand, namely, desalination, which has a capital cost of approximately $10,000 per acre-foot, or water reclamation and recycling, which is currently being pursued as a regional solution to water needs by Sewer Authority Mid-Coastside.

These are all future projects that would be paid for entirely by new development, not existing customers, after MWSD has brought the antiquated Citizens Utilities system up to contemporary water system design standards as promised in the Measure V campaign in 2001. The community committed, by an 80.66% vote, to the direction undertaken by the MWSD Board.

Better, cheaper water sources available to MWSD

Desalination is reliable, drought-proof, and has a predictable and dependable yield. A desalination plant can be built in modules, as capacity is needed. Desalination is generally viewed as a high-cost water source with potential environmental problems. However, as illustrated by a quick "back of the envelope" type sanity check calculation, it is far less costly than potential water, of unknown reliability and quality, from the Devil’s Slide Tunnel.

Recycling is another future water supply option. Like desalination, it is reliable and drought-proof. Major obstacles to use of recycled water include cost of treatment to meet needs of the floriculture industry and public perception of "toilet to tap" in some communities (locally, for example, Redwood City).

MWSD also has the new Alta Vista Well as an additional water source. Reliable yield and permitting issues are still being worked out with the Coastal Commission.

For those who base their decisions on facts, I hope this will put the issue of water from the Devil’s Slide Tunnel as a solution to MWSD’s water shortage problems to rest. It is not an economically viable solution.

Click below for more…

What about an intertie to NCCWD?

Mr. Gardner also brings up his view that interconnection to the North Coast County Water District (NCCWD) system would be beneficial. The community can evaluate the cost estimates for construction of a pipeline against the perceived benefits, and decide whether that is an improvement that the Montara / Moss Beach community wants to pay for.

NCCWD gets 100% of its water from the San Francisco Public Utility Commission facilities, already pre-treated using a different (and incompatible) disinfection process than either MWSD or CCWD. Therefore, capital costs of conversion of existing clorination systems to cloramine treatment would add to the cost. Additionally, such an interconnect and conversion to cloramine would preclude an intertie to CCWD.

MWSD already has identified in its 2004 Water System Master Plan that an eventual intertie to the CCWD system would be desirable. That document has been approved by the Board. Therefore, the claim that MWSD has no plan for an intertie to CCWD is also a falsehood, no matter how many times it is repeated.

Celebrate the Community’s Achievements on August 24

Your local Montara Water and Sanitary District Board of Directors has moved aggressively to resolve the long-standing problems with the water system operated by Citizens Utilities. We are just coming up to our Fifth Anniversary for the water system as a public service, and the Fiftieth Anniversary of the District.

Community members who want to know more are encouraged to attend our Fiftieth Anniversary Celebration at the Point Montara Lighthouse, Sunday, August 24, 2008, from 1 p.m. to 4 p.m. More information will soon arrive with your water bill.

Paul seems to have been accommodated by Mr. Gardner’s answers to his questions on the recreation money thread, but I am most certainly not. The interwoven and crucial nature of the factors involved require more than offhand “trust me” type replies.

To wit:
“The current yield of dewatering from the tunnel is in the range of 25-50 gallons per minute.”

So, is this meant to imply this snapshot is reliable for the long term? Is this one-time water that is now being drained off by the bores or is it from underground sources that will be reliable indefinitely? As indicated by measurements made by competent hydrologists or those with related geologic expertise, what is the expected daily output of exploitable water from the tunnels throughout the year? That is crucial if the water is suggested as an ongoing source of supply for more overdevelopment in Montara and Moss Beach.

“The contaminents that need to be removed are similar to those found in drinking water wells.”

Okay, we have had chemistry and geology courses and know that drinking water wells vary greatly from place to place, so what are the contaminants? In what concentrations? Is the water brought up to drinking water standards by the current treatment? If not, what additional treatment would be necessary? What is being done with the contaminants now being removed from the tunnels’ water? How much energy is being used in the treatment? How much is the current treatment costing on a unit of water basis?

“The drainage is intercepted prior to any physical contaminents [sic], and to my knowledge Kiewit has complied will all NPDES permits. Caltrans has some very stringent rules and a redundent [sic] system is nessasary.”

By “physical contaminants” do you mean contaminants from the construction process? (You will pardon some of us who have fought Caltrans for decades because of its institutional lack of even basic environmental understanding in some areas if we are not automatically impressed by mention of its “rules.”)

“Yield will vary during drought, since we’re in one it will most likely go up.”

How do you define “drought.” If water recharge is important to your volume estimates, wouldn’t it be prudent to observe, or at least calculate, what volumes will be available from that location throughout the year in a real, extended drought of the sort that have occurred during the past 50 or (better given the planet’s changing climate) 100 years? You suggest a supply of water on which people would be dependent through all kinds of weather and climate regimes to be reasonably expected around here. 

“A small package plant can be installed to treat the water to public standards in the neighborhood of (how much “use it or lose it?) about $1 million bucks. A pipeline can be installed to tie-into the existing system for about another $3 mill (2 years of “use it or lose it?) Add on the cost and time for no-growth obstructionism citing the damage to the highways environment and you can add another $3 mill and 5 years (about what was added to the El Granada pipeline).”

Don’t such estimates depend to a degree on an operation scaled to the volume of water to be treated and piped? What is the volume used in these estimates?

“The point here really is connectivity to Pacifica to the north. We can add 15-20% capacity of locally produced water, have flexibility to obtain Hetch-Hatchy water from the north (and south with a connection to CCWD water (which by the way, has connectivity to pump from Crystal Springs), and we wouldn’t have to rely on some “plan” to bring trucks over Devil’s Slide or 92 in an emergency.”

Does the NCCWD have water to spare? Does the CCWD have water to spare? Does San Francisco’s Hetch Hetchy System have water to spare? Isn’t it fiscally and ethically responsible to guarantee the availability of excess, sustainable, non-environmentally damaging water from outside sources over the long term and, especially, during low-water periods before using taxpayer money on expensive infrastructure to transport that water?

“I hoped this helped you, now I am going back to work.”

Thanks for your time. May we in the communities that depend on the MWSD look forward to more help in the form of answers to the follow-up questions above?

Minor clarifications

Regular readers of my postings know that I strive for 100% perfection in facts, quotes, spelling, grammar, and references. Unfortunately, occasionally I slip up.

I used the term “acre-foot” as it is often used colloquially when talking about water supplies, but technically speaking, an acre-foot is a measure of volume (specifically, the amount of water that will cover an area of one acre to a depth of one foot; approximately 325,000 gallons).

In each of the places I used the term acre-foot or acre-feet, as should be clear from the context, we are discussing a rate, not a volume. The exact phrase should be “acre-foot per year” or “acre-feet per year”. This gets rather unwieldy when you are discussing the annual cost of a supply capacity, i.e., dollars per year per acre-foot per year of production capacity.

Also, it is the San Francisco Public Utilities Commission (plural, they also manage power generated from the Hetch Hetchy system).


You conveniently left out the operational cost of desalinization. The cost of operating a plant once built will far outstrip the infrastructure to provide connectivity to the north, yes even beyond the tunnel.

In my opinion, desalinization is a foolish quest to merely end up spending what money we have so our options are further limited.

The San Francisco PUC has embarked on a major $3 billion dollar upgrade of the Hetch Hetchy system to provide safe reliable water.

We should put our hopes for the future in connectivity, not some well that may or may not ever come on line.


You probably haven’t been following water issues closely since you’ve been so busy with CUSD, but the Hetch Hetchy upgrade you mention is expected to triple the cost of water delivered by the SFPUC. CCWD depends on SFPUC for more than 82% of its supply, so those increases must be passed on to CCWD customers. That’s one of the reasons that CCWD rates are going up 14% this year alone.

If I understand you correctly, in this drought year (and perhaps next, and the one following it), you’d rather have MWSD connected to CCWD (which is already asking for reductions in use by its customers), which is connected to SFPUC, where 30 other water agencies will be fighting over limited supplies during the drought. How does this get us more water?

Those other water districts are fostering growth in their areas, too. More people competing for a dwindling supply - sounds a lot like the oil crisis, and a recipe for disaster. We can be smarter in our community.

And a few years out, you’d want to see your water rates go up to cover the Hetch Hetchy costs?

Customers of CCWD have seen their water rates go up by 98% since Jim Larimer joined their board. Would you like to see MWSD’s rates tied in to that system, too? Our rates here in Montara / Moss Beach, over the same period, are up less than 17% for base tier residential users.

The MWSD Board promised the community we would prevent the 108% rate increases proposed by Citizens Utilities, and we have done that.


I offer the following rebuttal to your summary:

Far less Devil’s Slide Tunnel water is available than claimed

(Actually far more water is available if connected to the north through Pacifica and SFPUC your “summary” is based solely on the dewatering of one tunnel and distorts the facts. You might add for the public’s benefit this connection can be used on an “as-needed basis” and not drive up costs as you proclaim)

Its reliability is not yet proven

(Connection to SFPUC is more reliable than failed wells)

Construction costs could be $175,000 per acre-foot or more for pipelines and treatment

(based on your scewed numbers. However it would be far less than squandering our money on a desal plant that will never be built.)

Proven alternatives can be built at approximately $10,000 per acre-foot

(and operated at such a cost it would bankrupt MWSD)

Recycling water may provide new water, cost savings and environmental benefits for Montara / Moss Beach citizens

(I agree, I just finished a recycling plant in Petaluma, we should look at doing the same at the SAM plant.)

MWSD’s new Alta Vista Well may solve much of the existing water supply deficit

(When do you expect it to be fully available? When do you project the moratorium to be lifted? 2012? 2020? 2050? What would be your best guess at this time? Pick a date, not a diatribe please.


We are talking about Devil’s Slide water, not SFPUC water. Please stay on topic.

Watch what happens to SFPUC deliveries as the current drought in California worsens, then come back and report on reliability.

The construction costs were based on your facts and estimates, not mine.

Recycling is being pursued by MWSD through our participation in SAM. It also is expensive and years away from supplying any water.

We expect the Alta Vista Well to be fully available following permit approval by the California Coastal Commission, expiration of any filing periods for litigation, and final approval by the California Department of Public Health.

Half Moon Bay’s experience with Beachwood cautions against predicting when a moratorium might end.

Mr. Gardner,

I assume those who want to take over the MWSD for their own purposes will have many conversations with Paul and other members of our MWSD board. The several of you repeatedly attacking the board obviously have a communication problem with them, one that prevents you from understanding the answers already provided by them and by district printed materials and websites.

But instead of non sequiturs, red herrings, and the like, do you have any answers to the questions I posed above? Numbers and definitions, please. I are a high school gradiate and can handle them. And figures of the sort I requested are necessary to move on to succeeding questions that would need to be asked before a picture can be built that would recommend the so-far mythic tunnel water to we customers of the district.

Julia Scott of the San Mateo County Times scooped the Half Moon Bay Review and Pescadero Pebble on an important local story. She also did significant independent research, spoke with CalTrans, Montara Water and Sanitary District, and North Coast County Water District people, and uncovered facts that contradict Charlie Gardner’s claims (and of course totally repudiate Jim Larimer’s fanciful claim of 1000 gallons per minute).

“Hopes of finding water trove under Montara dry up”, published in the San Mateo County Times on Monday, June 30, 2008, reports:

“According to a recent assessment by Devil’s Slide tunnel project manager Skip Sowko, the largest volume of water discovered so far at about a quarter of the way into the tunnels is 7.92 gallons per minute (or 30 liters per minute). A typical person in the shower uses six gallons of water per minute.” [emphasis added]

The article also goes on to describe some of the contaminants, which contribute to turbidity in drinking water and sometimes make water unsuitable for treatment:

“The state Department of Transportation pumps all the water it finds into storage tanks. The silt and clay must be removed before the water is discharged into the ocean.”

Here’s the link to the full story so you can read it yourself. http://www.contracostatimes.com/ci_9747980