GrokSurf's San Diego

Local observations on water, environment, technology, law & politics

A quick look at the San Vicente Dam-raising project

Posted by George J Janczyn on October 13, 2009

It has been about three months since the official groundbreaking for the San Vicente Dam raising project. The dam is currently 220 feet tall and when completed, will be 117 feet taller, increasing its holding capacity from 90,000 acre-feet to 242,000 acre-feet. My earlier post on the groundbreaking has links for additional details on the project. Access to the dam site is restricted, but I’m on the waiting list for a project tour (which hasn’t been scheduled yet) and plan to report periodically on progress.

I was able to take a few pictures from outside the guarded entrance to the area. From that location only about half the dam is visible, the spillway near the tower is in the middle of the dam). There will be plenty of blasting of the canyon walls on both sides of the dam, and probably beneath the foot of the dam as well. There was activity on the big hill on the left, and in the second picture, look above the dam on the right side of the canyon. You can see work done where the raised dam will make contact. Imagine operating the tractor that had to dig that road/trail to get up there!

Oct12Construction4

Oct12Construction3

CrossSectionDiagram

(See also this June construction update for a good picture showing the entire face of the dam)

[Nov 18: SDCWA has posted a photographic tour of the dam site on their website]

2 Responses to “A quick look at the San Vicente Dam-raising project”

  1. Hi George,

    I was just looking at some of your blog entries about the San Vicente Dam Raise project and just wanted to help answer a couple of the questions you had on there.

    The San Vicente Dam Raise project will fulfill two purposes for the San Diego County Water Authority: emergency water storage and carryover water storage. The original plan for San Vicente was to raise the height of the dam 54 feet as part of the Water Authority’s Emergency Storage Project, which is a system of reservoirs, interconnected pipelines, and pumping stations designed to make water available to the San Diego region in the event of an interruption in imported water deliveries. Here’s a link to the Emergency Storage Project fact sheet, if you’d like more background on the overall project: http://www.sdcwa.org/infra/pdf/ESP_factsheet.pdf.

    The Water Authority determined that they also needed to store additional water for “carryover storage” use, which means they’d have a place to store excess water during wet years, for use during dry years. Currently, the Water Authority has no reservoirs that fulfill this purpose. It was determined that the best way to store that additional water would be to
    raise San Vicente Dam even higher, since that project was already in the works. Another EIR/EIS was completed and approved in April 2008 for this additional raise. There’s a link to that final document in the Project Description section of the San Vicente Dam Raise web page
    (http://www.sdcwa.org/infra/esp-sanvicentedamraise.phtml), or here’s a direct link to the final EIR/EIS: http://www.sdcwa.org/infra/cip-CSPEIR.phtml.

    So, San Vicente Dam will be raised 117 feet and once complete, will be able to store an additional 152,000 acre-feet of water. 52,000 acre-feet will be held in reserve for use during emergencies, if the region’s imported water supply is cut off. The additional 100,000 acre-feet will be used for carryover storage purposes – to store water during wet years, for use during
    dry years.

    Once the project is complete, the reservoir will be filled with imported water from the Colorado River and Northern California. The Water Authority’s First Aqueduct (which brings in this imported water) flows into San Vicente Reservoir. Of course, if we are still in a drought and our water supplies are limited, it may take longer to fill the reservoir when the construction is complete. And if it rains, the reservoir may fill up quicker. That all
    depends on what our situation is like at the time. The plan is to begin filling the reservoir in 2012 or 2013, after construction is complete, and we anticipate water reaching the boat launch ramp between 2014 and 2017, which means the reservoir could reopen to recreation. The reservoir will not need to fill up completely in order for the boat launch to be accessible. The city of San Diego will still own and operate the reservoir and manage the boating activities.

    We should have a photo tour of the current construction up on the project website soon too, so check back there soon for photos of construction (http://www.sdcwa.org/infra/esp-sanvicentedamraise.phtml). I hope that helps answer some of your questions about the project. Please let us know (by using the contact information below), if you’d like any more information.

    Thank you,
    Jessica Berlin
    Public Affairs Consultant
    San Diego County Water Authority

    Project Information Line: 877-426-2010
    Project Email: ESPinfo@sdcwa.org
    Website: http://cip-esp.sdcwa.org

  2. michelle wilson said

    what will the effect of this project be on the floodway and floodplain-designated properties in the area below the dam? will this change or remove the designator, since it changes the flooding situation?

Leave a comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s