Delta Watermaster Craig Wilson updates the State Water Board on water use in the Delta, Term 91, and more

Watermaster SlideAt the January 21st State Water Resources Control Board meeting, Delta Watermaster Craig Wilson updated the Board on the activities of his office, which include the collection of data on water use in the Delta, permits in the larger Delta watershed and specifically about Term 91 and how it’s been implemented uniquely this year, a new interactive Delta water use map that is now available, and how his office is responding to drought conditions, which includes water transfers, modifications to water quality standards, and curtailment notices.

Water Use in the Delta: More certainty

The 2009 water reform legislation brought Delta diverters into the Statements of Water Diversion and Use program for the first time, began Delta Watermaster Craig Wilson.  This meant about 2000 additional statements were filed in 2010 which included information about diversion points as well as identifying the diverters involved.  Those statements did not include detailed information on water measurement and use; however, the legislation did say that water measurement data would have to start being filed electronically after three years.  The statements received in 2013 included this additional information on actual water use and water diversion.  There was 99+% compliance with the reporting requirements, noted Mr. Wilson.  He also noted that this is the first time we have detailed information on in-Delta diversions.

Those who were filing the reports had the option of either measuring their water use through a flow meter or another device based on best available technology, or if they could make a demonstration that that was not locally cost effective, they could estimate their water use by some other means, explained Mr. Wilson.  In the Delta, about 96% of the diverters chose that alternative, using a method called ‘crop duty estimates’ to estimate their water use.  This information came from the South and Central Delta water agencies who put together programs that enabled people to plug-in their acreage, what types of crops were being used, and the location in the Delta; this information was then fed into an algorithm to determine an estimate of water use, he said.

Delta irrigation intake #2 Mar 2009Mr. Wilson compared the totals given on the statements with the data that the Department of Water Resources had compiled on water use in the Delta, which totaled how much water was coming into the Delta as well as how much was going out through outflow and export; the remainder was water use in the Delta.  “Amazingly, the totals were very close,” he said.  “In both cases, the totals were about 1.5 MAF used and about 2 MAF diverted, so I was heartened by how close those numbers really were.”

To check the accuracy a little bit further, Mr. Wilson compared the individual results using the crop duty estimate algorithms against the records of another of the water districts who had a lengthy history with using flow meters and had kept very detailed records on their water use, and again, the totals were surprisingly close, he said. “They were within 10% of what the flow meters showed, so even though some people are somewhat critical of the fact that the most of the people in the Delta used these estimates, our conclusion was that the estimates seemed like they are at least in the ballpark regarding water use,” said Mr. Wilson.  “So I think we have more certainty than we have had in the past, not only on the number of people diverting water in the Delta, but also on the water use itself.”

The Delta watershed: Term 91

The Delta Watermaster’s authority extends to diversions in the Delta as well as to the conditions of permits in the larger Delta watershed, so the main way the issue of curtailments and permits is enforced is through application of Term 91, Mr. Wilson explained.  Term 91 is a permit condition that is placed on 100 or so junior water right holders in the Sacramento River watershed; it’s invoked when the major projects are releasing stored water to meet Delta water quality standards,” he said.

Because of the dry conditions, Term 91 was invoked very early and is still in place to this day, he said, noting that’s unprecedented to have Term 91 invoked in the wintertime period.  He said that a notice was sent out last week to additional water right permit holders whose their season use just started on January 1st“It’s not a large number of people, but I’m sure this is a historic first,” he said.  “Based on the way the water year is shaking out, we’ll also have to gear up for implementation of Term 91 to a larger group of people who start their irrigation season in the spring.  We’ll consider invoking curtailments under what’s known as Term 93, which is very similar to Term 91 but applies to the San Joaquin River watershed.

This is a first stage of what the Board might be considering invoking to even a larger number of people who don’t have permit conditions in their permits,” he said.

New Delta Interactive Water Rights Map now available

There is a new “Interactive Water Rights Map” available on the Delta Watermaster’s page that was put together by our staff with help from the Board’s IT and webmaster, he said.  Click on any island on the map and it displays the island, every diversion, and the permit, license, and statement involved.  “You can go to virtually any diversion that is taking place that’s been reported to us and get detailed information on just exactly what the diversion is, where it’s taking place and under what claim of water right, so it’s a pretty cool thing,” he said.  “We’re also putting up narratives for each island and tract that describe more in a narrative form what’s going on in the island and tract.”  He said they were hoping to do field checks this summer, but with the drought conditions, that might not be possible as staff might be needed for other purposes.

  • Click here for the new Interactive Water Rights Map for the Delta Watermaster’s office.

Delta Watermaster’s role in water shortage and drought activities: Water transfers, modifications to standards, and curtailment notices

There is a mix of authority with the Delta Watermaster’s role in water shortage and drought activities shared with the Board’s Division of Water Rights, said Mr. Wilson.

The Delta Watermaster’s office doesn’t have a lot to do with water transfers, although they’re involved in some meetings.  “One of the things that the Governor’s proclamation called for is the consideration of a consolidated place of use for the two major projects which will expedite transfers,” said Mr. Wilson.  “If that’s done, the amount of transfers that the Board itself will be relatively small.  It will be transferred between individuals or districts out of their particular area.

He noted that the Board has been very good on transfers in the past, and there is a lot of coordination and meetings with DWR.  “I think we’ll be very nimble in this area and it should work out well,” he said.  “I’ve offered at least one of my staff to help with the Division of Water Rights on processing any transfers.  I’m not sure they’ll even need that help but it’s available.”

Watermaster 1The Governor’s proclamation now allows us to process temporary urgency changes to the water right permits that would allow modification of the underlying standards, he said.  “That’s going to be an interesting process because as of February 1st, there are quite a few of the more stringent standards in our D1641 permits to the projects and the underlying 2006 water quality control plan that kick in, such as Delta outflows requirements, so we can expect to see requests to make modifications to that,” said Mr. Wilson.  “I’m not going to prejudge those.  We’ve been working with the project people and trying explaining what kind of information we would like to see to process those very quickly.”  He noted that the temporary urgency change process is very expedited and the staff will be able to make the changes in just a number of days.

On the same day the drought proclamation was issued, the Watermaster sent out a notice on that there would be a possibility that later this year, based on water conditions, many people with water rights that are dependent upon certain uses of water they have relied on for a long time could possibly see curtailments if it comes to a situation where most of the water in the major water courses is stored water being released by the projects and there is very little natural or abandoned flow, he said.  “We may have to be faced with the dismal prospect of notifying people that are fairly senior water rights holders that there may not be water available for them to divert,” said Mr. Wilson.  He said that they were gearing up for the inspection process to verify that water is being used fairly and correctly by all.

Some of these decisions we’re going to have to make this spring and summer will require sacrifices by all,” said Mr. Wilson.  “North of the Delta, in the Delta, south of the Delta, agricultural users, urban users, fishery people – all we can try to do is the best we can based on the information that we have, after listening to everybody and trying to get as much input as we can.”

Board member discussion

Board member Fran Spivy-Weber asked what the Board should be paying most attention to in order to anticipate what’s coming down the pike.

There are a lot of players and a lot of moving parts, and a lot of it is driven by Mother Nature, Mr. Wilson replied.  “You read these weather forecasts and you hear this parade of horribles with a very low carry-over storage by the reservoirs, almost no snowpack to feed into those reservoirs, and every weather forecast I’ve heard over the next week to next month to next three months, is pretty dismal, so we know with at least some realistic expectation that we’re going to be dealing with very dry conditions,” he said.  “We also know that those dry conditions are going to make it virtually impossible to operate business as usual, so we have to start making these decisions as quickly as we can.  I think the Governor’s proclamation gives us good road map on how to operate in both water transfer areas to try to transfer water where it’s most needed, deal with the standards situation and possibly deal with curtailment of water use.”

Another board member (sorry, I am working with audio only) asked about Term 93 and if it had been used in the past.

Rarely,” responded Mr. Wilson.  “It’s been used probably a couple of times in the last 20 years or so.  It’s a term that relates to how much water is being released out of New Melones reservoir to help maintain flow and salinity at Vernalis, which is just at the edge of the Delta on the east side.  It could be invoked this year based on what we’re looking at with the data.  Around 100 people would be affected, it’s most of the permits and licensees that are up on the San Joaquin River watershed.  What we would do, as we’ve done with Term 91, is to do the calculations and put out an advance notice to people to give them the information that it is possible that this could be invoked this year.

“It hasn’t been for at least close to 20 years,” he added.

For more information:

  • Click here to visit the Delta Watermaster’s office online.
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