Proposed pipeline to link San Luis Obispo and Monterey counties

May 2, 2013

water2Lake Nacimiento water management officials want to construct a pipeline to divert extra water to Monterey County. [MontereyCountyWeekly]

Nacimiento Lake fills up three times faster than Lake San Antonio, located a few miles to its north in Monterey County. During the rainy season, extra Nacimiento water is released into the Salinas River for flood control.

Nacimiento Regional Water Management Advisory Committee (NRWMAC), which represents lake-area homeowners and recreational users, is looking to construct an 11,000-to-14,000-foot pipeline that would divert excess water to Lake San Antonio.

Proponents of the pipeline say it would keep Nacimiento Lake levels higher in the summer, reduce flood risk along the Salinas River, help prevent seawater intrusion and boost Salinas Valley’s water supply in the dry season.

“They were releasing a bunch of rainwater that was just going to the ocean. Well, that’s a waste,” said NRWMAC President Mark Nielsen to the Monterey County Weekly. “We needed a big tank to store the extra water in. And the big tank is Lake San Antonio.”

In order to prevent flooding, Nacimiento released an average of 53,000 acre-feet per year from 1991 through 2005, according to a NRWMAC report.

The inter-lake pipeline was included in a 1991 Monterey County Water Resources Agency (MCWRA) list of 34 potential projects to deal with Salinas Valley seawater intrusion. The state has ordered one district in Monterey County to cut back 70 percent of Carmel River pumping by the end of 2016.

“This is a really good project, and it has multiple benefits for multiple stakeholders,” MCWRA Assistant General Manager Robert Johnson told the Monterey County Weekly.

In the meantime, Nacimiento’s advisory committee needs funding to further analyze the pipeline project that is slated to cost between $40 million and $90 million.

“If the Peninsula could pay for it and they need the water,” Nielsen told the Monterey County Weekly, “Maybe there’s a win for everybody.”


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I’m sure much of that excess that flows into the Salinas river helps recharge the groundwater for the alfalfa growers on the east side of the river. Ground water basin levels drop and they put farmers out of business. Nice move. Next time think beyond the end of your nose.

Confused? Best to just read the linked article in the Monterey County Weekly. It not only gives context to the issue, but adds the prospect of a water grab by Carmel. The pipeline project means absolutely nothing for SLO Co. residents not owning property @ Lake Naci.

What do the migratory fish have to say about this? Are the Greeies to busy building new Eco-Homes and traveling the world to SAVE more good memories? I say leave it alone because the original project should be enough for storm management and a sustained summer fresh water flow.

The water would come from a SLO County source and be piped into Monterey County to stop sea water intrusion up near Moss Landing?

SLO County has had a prescriptive rightsince 1959 to 17,500 acre feet of Nacimiento Lake water first, then the balance used by Monterey County to keep the live stream flow running down the Salinas River that would wind up in Moss Landing. The Naci Pipeline was completed in 2010 and then 15,750 acre feet of the allotment is sent south to SLO to the water treatment plant.

Their seawater intrusion stretches from Moss Landing to Seaside and inland about 10 miles to the Salinas city limits. It has been documented since 1944, so the Nacimiento Dam was not the cause. It was overpumping by the farmers in the area between Salinas and the ocean. Complete emptying Lake Naci would not stop that sea water intrusion.

This appears to only benefit the property owners around Lake San Antonio.

Regardless of this proposed pipelline, SLO County is still entitled to its 15,000 or so acre feet per year.

Thanks for details that could have been included in the article if the person writing it had taken the time to do a bit of research.

If you want to know about the Monterey sea water intrusion you can start at:

There is more information at the root website.

I agree with Nielson’s premise that fresh water is “wasted” once it is allowed to run to the sea (the steelhead would probably beg to differ). Seems like Lake San Antonio is a big empty drum, waiting to be filled by the Naci excess. Other than $6400/foot to build, this seems like an elegant solution.

They say “This is a really good project, and it has multiple benefits for multiple stakeholders,” I say not much good for boaters and people who own homes at Lake Nacimiento


If the excess storm water is already being “dumped” into the Salinas River, there ought to be zero effect on the Nacimentians.

Or did I miss something?

Follow the $$$$$$$$$$$$$

“Nacimentians” sounds like a native American people, albeit with serious-ass ski and party boats.

This caught my eye. Seawater intrusion? Are we talking the river or lake? In either case with the distance from ocean and we are talking this? I have only heard of this possibility before with wells etc. that are within a few miles of the ocean. Something stange here.

They are probably talking about seawater intrusion into the water table near the mouth of the Salinas River when it dries up. I don’t know how much this would help that but it might.

At $90 million and 14,000 feet… That’s over $6,400 per foot!

You forgot to include the unionized government variable. It’s a simple multiplicative of around 10, but is only applied after approval.