DWR’s Paul Helliker discusses temporary dams in the Delta for salinity control
On yesterday’s edition of Insights on Capitol Radio, host Beth Ruyak discusses the temporary dams that are being proposed for the Delta with Deputy Director of the Department of Water Resources, Paul Helliker. Here is a transcript of their discussion:
(Note: For ease of reading, only Paul Helliker’s remarks will be in italics; the host, Beth Ruyak, will appear in regular type.)
Beth Ruyak, host: California water officials are gathering permits, they are notifying property owners because they have three temporary dams in a plan that could be put into place in the Delta as early as May 1st, that’s if the current drought conditions continue. Paul Helliker, Deputy Director of Water Rseources, the Chief of the South Delta branch, is joining me by phone this morning. Mr. Helliker, welcome to Insight.
Paul Helliker: Good morning.
Where is the process today toward constructing these dams?
We’re working very quickly to make sure that we have the permits necessary and have the designs ready to go. As you mentioned, May 1st is our current target.
What’s the deciding criteria? I’d like to be as specific as you can be.
The deciding criteria in terms of when or where?
Both. Well, where we know, but when?
The where, we’ve got locations that you mentioned, and those are locations that are similar to the barriers that we put in in 1977. And these locations will help to keep salinity out of the middle part of the Delta, the one at False River, and then two barriers that would be in the northern part of the Delta would help to keep water in the Sacramento River so that it provides the force we need to repel the salinity as much as possible.
What does or doesn’t make a difference with that May 1st target and then beyond May 1st?
The reason that we’re looking at May 1st is that the reservoirs this year are very low, and there’s not enough water in them at this point to be able to meet all the needs that we have for water users and fisheries, benefits, and so on, so we’re trying to find the balance between how do we make sure we have enough water in storage to meet as many uses as we can, but also to minimize the amount of water that has to be released both to protect fish and also to repel salinity in the Delta. If salinity increases significantly in the Delta, than the water will be unusable.
Tell me about the measurement of salinity – can you give me numbers that you’re watching?
There are multiple measurements, but the one that we’re using as our criterion is electrical conductivity, and so our threshold level that we’re trying to avoid the water going above is 1000 millimhos per centimeter – that is the actual term, but 1000 is the number. Right now the salinity is below that, but we’re seeing the inflows drop off from these recent storms and so fairly soon we’re going to be down to minimal inflows in the Delta and that’s the main concern.
How far below is that number right now?
At different points in the Delta, it’s down in the 100, 200, 300 salinity level range, but that changes dramatically as tides come in and also as flows drop.
So if we get one more rain storm, just one more, before May 1st, does that push the date back?
Possibly. But again, we’re trying to strike the balance between when we would need to have the barriers in to save as much water as possible versus when we would want to avoid having impacts on fish, so most of the fish migration is finished by sometime in May, early June, so those are the days that we’re looking at as possible changes.
Ok, now I’m understanding a little bit more of this. You’re watching the fish as well as the salinity as well as the weather forecasts, correct?
Yes, the Delta is a very complicated ecosystem and we have multiple species of fish that use it to migrate both in and out, and so one of the things that we’re looking at is how to make these barriers as fish friendly as possible. We will be putting culverts in the barriers so that fish that are migrating can use those, and we can close them as well, in case the salinity starts to become unacceptable. So we’ll have a variety of ways of being flexible with these barriers.
That is a different picture, though, than just saying we need the permits and the property owners permission and then we begin construction. This sounds like a real moving target, if that’s the right way to say it.
We’re designing the barriers now. We have some initial designs. We met yesterday and discussed with the fisheries agencies some modifications that could help, but we have the basic design. They are going to be rock barriers and so how we put culverts in and where we put them, we’re still finalizing, and we’re also in the process of developing the information that would be necessary to get the permits. Our goal is to have all of that completed by the end of this month so we can submit it to the permitting agencies.
You mentioned the landowners. We have contacted the landowners who own the property where the barriers would be located, so that they are familiar with it and in case we need access to the levees there, than we would be able to do so.
Is there a citizen’s voice in this process?
We are going to be meeting next week with all the landowners to get their input. The point of these barriers is to protect water quality of all of the users in the Delta, so the landowners who are in the Delta, they will be benefiting by these barriers because it will help us provide better quality water throughout the course of the year.
The downside though is farmers and landowners and the communities in the North Delta area, they depend on the water from two of the water sources, the Sutter Slough and the Steamboat Slough where rock barriers will be placed. What’s your response to them?
This year, as opposed to what we did in the 70s, we will have water quality monitoring stations, and like I said, we do have the flexibility to provide flows through the barriers. The barriers themselves are permeable. So we will be monitoring water quality on a daily basis and possibly on an hourly basis and we will be assuring that the water is not unusable.
So those two rock barriers in Sutter Slough and Steamboat Slough have a goal to actually keep the fresh water in the river, and that’s different from the barrier in False River. Will you explain the differentiation?
Yes, the barriers in Sutter Slough and Steamboat Slough are designed to try to keep as much water flowing down the Sacramento River rather than flowing into those two sloughs, so that the water in the Sacramento River can push the salinity gradient out as much as possible. The False River dam would help that because it would provide a barrier for water that would normally flow into the middle part of the Delta, Frank’s Tract and so on, and so that would allow the flows down the Sacramento River to repel the salinity as much as possible.
Obviously, there’s concern about the farmers and concern about the fish. Could you speak to a moment about the fragile situation with the Delta, with the estuary, and that balance of freshwater and saltwater?
This year, it’s now the third driest year on record. In previous years when we’ve had droughts of this magnitude, the Delta has become overwhelmed with salinity. We do have some water in storage that we can use to try to provide good quality water in the Delta, but without these barriers, we will likely see that the situation will become intolerable sometime in the summer.
How effective were the barriers in that 76-77 drought?
They were very effective. In fact, if we hadn’t have had those barriers, then many, many places in California that rely on water from the Delta, including in the Delta, would not have been able to use that water.
Scientists tell us we could be in for a long-term dry spell. Is this a plan that even though we’re talking about sort of an emergency temporary situation May 1st, does it move from back burner to front burner now for a long period of time?
We’re looking now at what the conditions might be in 2015 as well, and preparing that situation, which is one of the reasons why we want to try to conserve as much water as possible in our reservoirs, in case that is a dry year as well. So we will put these barriers in on a temporary basis, they are rock barriers, we can take them out in the fall whenever there may be some flows coming into the Delta but then we’ll be ready to put them back in if we need to, if it’s a dry year again.
The project manager, Mr. Holderman, was quoted as saying it was about a 95% chance the barriers would go in. Is that the percent chance you would give it at this point?
I believe so. The weather report doesn’t look like there’s going to be a lot of precipitation in the next few weeks, and so chances for more precipitation this year are dwindling fast. And so our reservoir situation is pretty critical. And without these barriers, it’s going to become even more so.
State Water Resources Control Board has to sign off as well as the Army Corps of Engineers and the National Marine Fisheries Service. Have you gotten any of those okays yet?
No they need the permit application from us. We have been including them in all of our discussions. We have a team that’s focused on the fisheries issues; we meet at least weekly, sometimes more, to go over the design and in fact, I mentioned the conversations we had yesterday. We were looking at should we put notches in the weirs that would allow migrating fish to go over them or would culverts suffice, so we’re in the middle of conversations now to try and optimize the design.
So fish are high on the priority list for this decision?
Fish are critical, but so are every other user of water, so we’re trying to balance all the different needs, but because a number of species are listed as threatened or endangered, we need to be particularly careful with them.
Thank you for your time, thank you for the information, we’ll continue to follow this with you.
For more information …
- Insight: Temporary Dams In The Delta, webpage from Capital Public Radio