The trials and tribulations of building a 45-mile pipe

One of the most recognized water projects in the State of California is the California

Aqueduct, a shimmering ribbon of water that can be seen from Highway 5. Along with 34 reservoirs, the State Water Project (SWP) in total consists of 444 miles of tunnels, tubes and canals, all moving water from where it falls to where it is needed.

This past week, I attended a tour of a future project that would add 45 miles of pipe to the State’s existing 444.  The project is called the Delta Conveyance Project (DCP) and the tour was a chance for agencies that plan to transport water through the project to see, firsthand, where different parts of the infrastructure will be built. We visited where the two intake pipes will be built, as well as the various sites for construction and staging shafts. We also visited the manufacturer of fish screens. I was surprised to find that fish screens are much more interesting than I anticipated.

In this blog, a few questions will be answered:

To the right is Bethany reservoir. To the left a few miles is Clifton Court Forebay. A forebay is a smaller pool of water for settling out debris before it goes to the next step, in this case, piped to Bethany Reservoir.

1.        What is the DCP?

Looking out to Clifton Forebay from Bethany. Where we were standing is where pumps will be put in to pump water into the aqueduct from Clifton Court Forebay

2.        What is the Delta?

3.        Why is it needed?

4.        Why is Valley Water involved?

5.        How is it governed?

6.        And what are the perspectives of the opposing stakeholders?

There are lots of resources here so feel free to click through and read/watch lots of good information. And, my usual caveat: As a Valley Water Director, I’m am not an expert as I fly at the policy level. That said, I want to share with you all what I’m learning. It is fascinating!

What is the DCP: The DCP is the latest episode of a long running telenovela. You may recognize it under the different names of the project over the years including the “peripheral canal”, the “twin tunnels”, the “water fix” and now the Delta Conveyance Project. Each version has been slightly different.

At its core, this version of the project is a 45-mile pipe that would divert water from north of the Delta near the towns of Hood and Clarksberg and move it underground all the way to Bethany reservoir near Byron. The pipe would be 36 feet wide at a depth of 100-130 feet.

What is the problem the DCP is trying to solve? Taking a big step back, most of the State’s water falls in the north but is needed elsewhere. Hence, the hundreds of miles of pipes, canals and reservoirs built and managed by the state and federal government, as well as Valley Water. (VW has 10 reservoirs to capture local water and store imported water delivered through 150 miles of pipes to the retailers that then sell it to you.)

At present, the State Water project sucks water out of the Delta from the Banks pumping plant near the Bethany reservoir, which is at the southern end of the Delta. That water is then pumped into the California Aqueduct (and a pipe that goes to our territory) to serve 27 million people along with 750,000 acres of farmland.

Several issues have threatened the reliability of delivering water this way, meaning through the Banks pumping station after the water flows through the Delta. They include:

-              The Banks pumping plant forces water to move in ways that are unnatural, messing up the ecosystem

-              Endangered fish get sucked to where they are not supposed to be

-              Water quality is increasingly threatened due to sea level rise, meaning, more salt water will intrude into the Delta making our water supply more saline

-              With climate change, more water will be falling from the sky in shorter, fiercer bursts , instead of being frozen as snowpack, and we have no way of catching that water with the current system before it flows to the sea

-              There is a general need to build new projects because of aging infrastructure, seismic threats, and anticipated changes due to climate change

What is the Delta? In order to comprehend this project, it’s important to understand the Bay Delta, the place where fresh water from our snowpack flows through the Sacramento and San Joaquin rivers to meet the salt water of the San Francisco Bay. This mixing of water and the constant flushing based on tidal rhythms and the ever-changing weather and snow melt-based flows makes for a very unique ecosystem. This ecosystem plays a critical role in the health of our region providing a stopover for migrating birds and essential fish habitat.

Layer onto that the fact that the US government, back in the days before, during and after the Gold Rush, basically begged people to clear what were seasonal wetlands for farming. Land was pumped, levies erected, and the Delta is now home to 415,000 acres of farmland. Very good farmland due to a combination of factors like nutrient rich water from the mountains feeding a wetland ecosystem, the decomposition of which makes for excellent soil.

Why is Valley Water involved? Valley Water’s job is to supply water to the 2 million

At Big Break Park standing on a cool map of the Delta.

residents and businesses in Santa Clara County. The way it currently does that is by capturing local water in our ten reservoirs, pumping groundwater in a way that is sustainable, and recycling and purifying water. But those local ways of supplying water only account for about 50% of our water. The rest is imported, starting as rain in the Sierras, flowing through the Sacramento and San Joaquin Rivers, and then flowing through the Delta where it is then guided through pumps and pipes to us.

In essence, 50% of the water for Santa Clara County comes from outside of Santa Clara County. So, we have a vested interest in the reliability of the infrastructure used to suck water out of the Delta for our use. As a result, we are a member of and investor in the Delta Conveyance Project.

How is the DCP Governed? A Joint Powers Authority called the Delta Conveyance Design and Construction Authority (DCA) has been established to design and construct the DCP. It is overseen by a seven-member Board comprised of representatives from sixteen of the Public Water Agencies that are serviced by the Department of Water Resource’s State Water Project. The DCA is currently focused on design and engineering needed to support environmental review and permitting. The participating water agencies are:

Metropolitan Water District of Southern California, Kern County Water Agency, Santa Clara Valley Water District, Zone 7 Water District, Alameda County Water District, Santa Clarita Valley Water Agency, Dudley Ridge Water District, Antelope Valley-East, Kern Water Agency, Coachella Valley Water District, Crestline-Lake Arrowhead Water Agency, Mojave Water Agency, San Gabriel Valley Municipal Water Agency, San Bernardino Valley Municipal Water District, Desert Water Agency, San Gorgonio Pass Water Agency, Palmdale Water District.

I serve as an alternate to the Valley Water Board Chair, Tony Estremera on the DCA board.

What are the concerns? Oh goodness are there lots of concerns about this project! It might be likened to a local version of establishing peace in the Middle East. I’ll do my best to describe some of the issues here through the lens of different stakeholders but I’m an outsider trying to understand and relay what I’m learning, which is a poor substitution for getting information directly from those closest to the issues. The link here goes to another overview of the DCP that is very good and if you scroll waaaay down (keep scrolling!) you’ll see a list of stakeholder groups and links to them.

Farmers: Farmers fear that a new pipe upstream from farms will siphon their water away. That’s different than the current pumping plant which sucks water out after it goes through the Delta and by all the farms. (I’m overgeneralizing.)

Residents: The Delta is comprised of a little over a dozen tiny towns full of life, history, and character. Residents are mainly concerned that a project this size will disrupt their way of life. In particular, people are concerned about the construction impacts of the project, things like traffic. And they have reason to be. If you’ve been to the Delta, you know that traffic is highly constrained by two lane roads on a limited number of levies.

Environmentalists: Environmentalists believe that if the pipe is built, the state will divert

water out of the Delta to the point that this treasured and important ecosystem will be sacrificed to quench the thirst of Californians across the state.

Tribes: Tribes like the Bay Miwok, Coast Miwok, Plains Miwok, Maidu, Nisenan, Ohlone, Patwin, Pomo, Wappo, Wintun, and Yokuts have deep, historical connections to the Delta watershed. Concerns range from the degradation of the water and fisheries along with the loss of cultural resources.

Commercial Fishing Groups: Similar to environmentalists, commercial fishing groups are concerned that once built, the pipe will divert too much water and further degrade fish populations. At present, we’re in the third year of a ban on commercial salmon fishing. And the Delta Smelt are not doing well.

 As I’m piecing things together and trying to understand project concerns, I’ve come to one overarching conclusion. The largest area of disagreement is around the use of the pipe. Opponents say that once it is built, it will suck all the water out of the Delta.

The response from project proponents is that the pipe will be used mainly to sip water before it enters the Delta when it falls from the sky in a big gulp, something that is happening more and more with climate change. They say, trust us, we will operate this new piece of infrastructure responsibly. What I hear from the other side is an unwillingness to trust.

To address these concerns, a stakeholder engagement process was set up. Strong opposition remains and the good staff at the DCA will continue to work with all parties to build a new pipe that secures water supplies and transport for the long term.

And I promised to talk about fish screens. I’ve included pictures here but my biggest takeaway was that while a fish screen seems very simple, (a screen to keep fish out of where they are not supposed to be) there’s actually a lot that goes into it. What materials do you use and how big are the holes so that fish don’t get sucked through and/or banged up? How do we keep the screens from getting all gunked up with algae and barnacles? And what about different temperatures and salinity, like an icey environment, in terms of operating the screens? Take a look at the pics and videos to learn more.

This mechanism lifts the screen out of the water periodically, like twice a day maybe, to go through the cleaning cycle where it spins and the brushes on the inside scrape all the gunk off. This is the type that would be used for the DCP and would sit in front of the gate that, when opened, would suck water in with the screen keeping the fish out.

You can see the brushes. As it spins, the brushes keep it clean. It will go through this cycle maybe twice a day.

This is a different type of screen than the ones that would be used for the DCP. The brushes are on the outside and spin around periodically to scrape off the gunk.