California Water Commission: Update on State Water Project operations and issues
Acting Deputy Director of the State Water Project reports on forced outages, and the status of planned maintenance and upgrades
One of the statutory responsibilities of the California Water Commission is to conduct an annual review of the progress of the construction and operation of the State Water Resources Development System and to submit a report on its findings to the Department of Water Resources and the Legislature, along with whatever recommendations the Commission deems appropriate. As part of that responsibility, DWR Acting Deputy Director for the State Water Project Mark Andersen briefed the Commission at their May 18th meeting on the key activities of the SWP, including operations and maintenance and administrative issues.
Mr. Andersen began with some good news. “We have a metric we use for the project we that we call ‘operational availability,’” he said. “Of our 180 or so turbines and pumps, our spinning machines, we have a metric that looks at the percentage of time those are available for full use. A few years ago, we were down to about 79%; that is not the historic low but towards the lower end for the project, and over the last few years, we’ve raised that back up to almost 86%. Our objective is 90%, which is one of our long term benchmarks.”
STATE WATER PROJECT ALLOCATION
Mr. Andersen then discussed the State Water Project allocation for the upcoming year. He presented a graphic of the Northern California 8-station index, noting that it’s about 120% of normal for the long-term average. “In the Northern Sierra, we’re slightly above normal and we still have a little bit of water year left, so that’s obviously been an encouraging picture after the last four years,” he said. “That’s not the whole story of course; as we go to the central and southern Sierra, and we go to reservoirs in central California and south, many of them are below their long-term average storages for this time of year.”
“The good news is that Shasta and Oroville are above their long-term averages, and of course with Oroville being at that level of storage, we have a 60% allocation to our 29 public water agency water contractors, so that’s about 2.5 million acre-feet out of our 4.1 MAF,” he said.
He presented a graph showing the history of water allocations for the State Water Project, noting that before the project was fully built out, deliveries were much smaller. “The long term average is right round 2.6, 2.7 MAF, so we’re close to that,” he said. “The storage in Oroville would suggest perhaps a higher allocation, but San Luis Reservoir, which is only about half full, is really a critical component of making those deliveries and the fact that that’s not full is really the driver for the 60%.”
Mr. Andersen then discussed some of the forced outages on the State Water Project. “We have lots of work we do on almost 700 miles of pipeline and aqueduct and the plants constantly and we’re always planning outages, but with a system that big, unforeseen outages occur,” he said. “We had a forced outage down in Kern County just north of the Buena Vista Pumping Plant which is before we go over the Tehachapis to get to Southern California. We had a significant boil that was detected on January 2nd of this year that at the peak, it was 8 cfs. Any time you are measuring boils in cfs, you got a big problem. It was over 3000 gallons per minute, and it was leaking into an adjacent Henry Miller canal, which is an irrigation ditch for the local ag folks. We dewatered the pool, and that takes a little bit of time. We had some other repairs planned for pool 30 as well that we had not gotten to yet.”
Mr. Andersen explained that the aqueduct is on the perimeter of the Buena Vista lakebed in a cut section; the sediments have a lot of evaporate deposits like gypsum. The concrete liner is designed to be as water tight as possible, but it is not water tight, so overtime the gypsum deposits underneath dissolved and it resulted in panel failures. There have been other boils in this reach. The canal was out of service for a little over 6 weeks; it was put back in service on February 26th.
“We did not miss any deliveries; all the southern California deliveries were made from our southern California reservoirs so we knew we had enough water there,” he said.
Mr. Andersen then showed slides of the damage and the repair, noting that they did work in four different spots, putting in 3300 feet of linear feet of liner; 10,000 cubic yards were excavated and recompacted, 2000 cubic yards of concrete for the new panels, and then over 400,000 square feet of a waterproof membrane called Terranap. “We’ve been using it on areas where the canal is prone to these boils and leaks. We put that over the liner and then we [put concrete] on top of that. We’ve been doing that about ten years or more, and those repairs are working out well.”
A commissioner asks if the damage was caused by subsidence. “This is not a subsidence issue at this location,” replied Mr. Andersen. “Around the Buena Vista Lake, very little subsidence of the aqueduct. Obviously further north up around Huron and so forth, yes, significant there.”
There was an aqueduct outage on the East Branch in the Antelope Valley at pool 49, milepost 336. There was a very rare intense thunderstorm that impacted the canal. “Some hydrologic estimates I saw were a 1000-year return frequency on some of the hour duration rainfall,” he said. “We had about 10,000 cubic yards of debris, sediment and trees go into pool 49. We had four pools affected but 49 was the worst. We had about a three week outage there and spent about $2.5 million getting all that stuff out of the canal, and getting it back in service without missing any deliveries.”
There was another forced outage on the North Bay Aqueduct due to a leak at the Napa Tank. “We discovered this large leak so we dewatered it again and it turned out there was this corrosion underneath the diffuser where the water comes into the tank. It comes into this big standpipe and it comes out the top. We welded in a new plate there on the bottom of that and fixed that. That was a couple weeks of outage and got that back in service.”
FACILITY UPGRADES AND REFURBISHMENTS
Alamo Pumping Plant
The Alamo Power Plant is on the East Branch of the aqueduct right after the bifurcation point on the south side of the Tehachapis. The plant has one 18 megawatt unit; the plant was designed and constructed so another unit could be installed. “We have a cap and trade submittal we’ll be submitting to the Department of Finance at the end of this month for a 12 megawatt hydro unit that we would put in this second bay,” he said. “It would allow us to get more clean hydropower for the project. The costs are in the mid $50 million and we think the benefits are really closer to the low $40 million as a net present value analysis, so that’s why we’re seeking the cap and trade money for the component that’s justifiable on benefits, and then the State Water Project would pay the balance. We’ve received cap and trade funding for other hydropower improvements on the Project in the past, so that’s pending.”
Ronald B. Robie Thermalito Pumping Plant
On Thanksgiving Day 2012, there was a fire at the Ronald B. Robie Thermalito Power Plant; the plant was unmanned so nobody was injured but the fire damage was extensive. Since the fire, $100 million has been spent so far on fire cleanup and plant refurbishments; they hope to have the plant back in operation by late 2018. There is $140 million planned in replacements and refurbishments to the plant, including a new roof, new coatings, and of course a new fire suppression system. Three units are being refurbished and one unit is being completely replaced with a new Kaplan unit. The plant will be capable of producing 125 megwatts.
Oroville Dam River Valve Outlet System
As a matter of prudent design and dam safety regulations, all dams need to have a low level outlet that in the case of an emergency can be used to lower the water level behind the dam and bypass the power plant. There was an accident at the river valve chamber in 2009; there was a subsequent investigation after which DWR entered into a settlement agreement with Cal OSHA and agreed to hire a third party engineering expert to get the system operational again and improve the safety.
“We’ve been working on that,” Mr. Andersen said. “The drought accelerated our efforts in 2014. We’re still working on a long-term fix but we shifted gears to get it operational. We actually did that between January of 2014 and July of 2014. We tested it, we worked with OSHA, DSOD, and FERC; and in 2014 & 2015, we put 500,000 AF through a mostly refurbished system.”
There’s still more work to be done, he said. They couldn’t complete the work on the baffle ring for 2014 & 2015, but half-capacity was enough to meet cold water requirements for temperature in the Feather River. “Without that, we would not have been able to meet those requirements, so it’s really a critically important component,” he said.
SOLAR POWER PROCUREMENT
The Department of Water Resources is continuing increase their use of solar power. They have a 20-year power purchase agreement to get 45 megawatts from the Camelot array, located near the town of Mojave. The Department also has a power purchase agreement with the Sol Verde project which will produce 85 megwatts when construction is completed. They have also leased some of the land at the Pearblossom Power Plant where a 10 megawatt array is being constructed.
Mr. Andersen lastly gave an update on the workforce. “The engineers currently have an agreement in place, an MOU that expires in 2018, gave them 7% over this year and next year. Unit 10 scientists, the MOU there is 15% over three years, also expires in 2018. Before we were losing a lot of our mechanics and electricians, but with your help and the help of others, we did get significant raises for those folks; that MOU expired in 2015, and we are having ongoing discussions with them.”
“But we certainly have a much better situation,” he continued. “You might recall that we have an apprentice program which is a four year program. There’s really no utility or hydropower entity in the country that has an apprenticeship program like this, and we were getting cherry picked pretty regularly. As soon as our folks would graduate, we wouldn’t even get a chance to use them at our facilities, but that has stabilized significantly with the gains we made in the last MOU. Those discussions are ongoing.”
For more information …
- Click here for the full agenda, meeting materials, and webcast link for the May 18th meeting of the California Water Commission.
- Click here for Mark Andersen’s full powerpoint presentation.
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