A panel discussion on agricultural water use and efficiency improvements made since the passage of the Water Conservation Act of 2009
California is the nation's largest farm state, providing half of the nation's fruits, vegetables, and nuts, as well as adding $40 billion to the state's GDP. Agriculture is the largest user of consumptive non-environmental water in the state, a fact that has come under fire recently in the press due to the exceptional drought conditions and the resulting tight water supplies.
The Water Conservation Act of 2009, passed as part of the landmark water reform legislation, set well-publicized targets for urban conservation, but contained some requirements for agriculture as well. How agriculture has responded since the passage of the legislation was the subject of a panel discussion at the California Water Law Symposium featuring Chief of DWR’s Water Use Efficiency Program Peter Brostrom, NRDC attorney Claire O'Connor, and attorney Mark Atlas from Downey Brand discussing the changes in agricultural water use efficiency since the passage of the legislation and the potential for further agricultural conservation and efficiency. The panel was moderated by attorney Katy Spanos, Assistant chief counsel with the Department of Water Resources.
Katy Spanos opened the panel by providing some context for the discussion. “Although agriculture is a relatively small part of California's economy, it has significance way beyond that percentage,” she said. “It's part of California's heritage, its history, and it’s important in both national and international agriculture economy.”
“Agriculture is the largest user of consumptive non-environmental water in California,” she continued. “Climate change, with its potential for more severe and longer and more intense droughts is — and other factors such as regulatory change — are going to reduce the amount of water available to agriculture and all other sectors of water as we move forward.”
“Agricultural water is often used and reused several times, and is critical to maintaining and sustaining many of our wildlife resources,” she said. “Agricultural efficiency is important, but alone it will not solve California's water problems. It is an essential part, however, of the water supply and water use picture.”
Ms. Spanos then presented a graphic from the California Water Plan, noting that this is not the often-talked about Governor’s Water Action Plan, but rather the statewide planning document that is produced every five years by the Department of Water Resources through a collaborative process that involves hundreds of different stakeholders.
“In the context of this plan, Secretary Laird, putting it in the context of what's been going on today, said, ‘The extreme drought gripping so much of California reminds us of the importance of the plan. Three years of dry weather are enough to force farmers to fallow hundreds of square miles, leave some small communities with dry taps and jeopardize cold-water species. Clearly we cannot take our water resources for granted. To meet the needs of a state as ecologically, economically and geographically diverse as California takes collaboration planning on a huge scale.’”
“Following up with the words of Mark Cowin, the Director of DWR, “To manage our water wisely, Californians need a shared understanding of our challenges and a vision for the future. The California Water Plan update delivers that and creates a path forward,’” she said.
Ms. Spanos noted that most of the speakers on the panels at the symposium have made the point that reasonable use is viewed in the context of the situation – of what is known, of what other uses are involved, and of what the climate, geography, and cultural communities are. “I think this report is certainly not the only tool, but is a significant and important tool for bringing all this information together as we try to collaboratively solve our problems in the future,” she said.
The panelists then began their presentations.
PETER BROSTROM, California Department of Water Resources, Water Use and Efficiency Program
“There are a lot of misconceptions, I think, in the general public about Ag water use efficiency, and what it can and cannot do, so I hope we can cover some of those issues today,” began Peter Brostrom.
He started by putting agricultural water use in the greater context of water use in California. “Going back to 2010, which is probably our most recent normal year when we received 210 million acre-feet (MAF) of precipitation across the state, of that, Californians either diverted or pumped 41 MAF for human uses, either agricultural or urban,” he said. “The other 170 MAF were transpired or evaporated in our forests, native vegetation or flowed out in our rivers to the sea. So that's where human use fits into that overall precipitation in a normal water year.”
“Of the 41.2 MAF, roughly 33 MAF were used by agriculture and 8.3 MAF were used for municipal or industrial purposes,” he said. “There were 8.6 million acres irrigated that year or estimated to be irrigated that year for agricultural purposes. That production, that irrigation accounted for roughly $37.5 billion in cash receipts in additional money or revenue in added value in canneries and where products are manufactured or produced based on agriculture.”
“California grows over 450 different crops,” Mr. Brostrom said, noting that this particular chart is a little misleading. “The first category here, Fresh Vegetables, is not really even fresh vegetables – that's truck crops, and it includes nurseries, and a conglomerate of a bunch of these different small crops. I think when we get new data in this year, the nut crops — almonds and pistachios – will have now taken over in terms of crop area.”
“Close behind that is alfalfa,” he said, noting that in an earlier panel, it was suggested that growing alfalfa may be considered as more of a ‘taste or fancy’ issue. “But as long as we're drinking milk, we need alfalfa grown in the state,” he pointed out.
He noted that vine crops, both fresh table grapes and vineyards, have increased dramatically over the past few years, and there is a significant amount of acres used as irrigated pasture primarily for cattle.
Mr. Brostrom said that in 2010, the price for corn was high; the price has dropped significantly so the acreage was likely less in 2014. “Other tree crops, like walnuts, apples, peaches, have increased significantly,” he said. “In the past, cotton, these grain crops were a much bigger part of our cropping picture. Now that they've dropped lower as we've made this switch towards more permanent crops. That makes it harder during drought years to manage our water supply, because in the past we could fallow more, but now with permanent crops, we have to find a water source for those trees.”
There are two components to agricultural water use efficiency – on-farm improvements and agricultural water supply improvements, Mr. Brostrom said. On-farm improvements can include irrigation scheduling — making sure you're applying the water when the crop needs it; irrigation system improvements such as switching to drip, and then land management practices like laser-leveling which smooths out the fields for more accurate furrow or surface-irrigation, he said. At the agricultural water supplier system level, canal-lining and canal automation and management can give better control of water being delivered to farmers, he said.
He then presented a slide from the California Water Plan showing the changes in irrigation methods from 1977 to 2010. He noted that the use of surface irrigation has been decreasing, while the use of drip and microspray has been increasing. “Some of that is due to the change in crop patterns,” he said. “Field crops tend to be surface-irrigated, and the new orchards that are going in are almost predominantly on drip and microsprays.”
He then briefly discussed the ways state and federal agencies provide support for agricultural water use efficiency.
The California Irrigation Management Information System or CIMIS has over 145 weather stations statewide, along with a satellite system called Spatial CIMIS which produces a map that shows evapotranspiration across the state on a daily basis using a 2-kilometer grid. “It provides accurate information for farmers to schedule their irrigation,” Mr. Brostrom said.
There are Cooperative Extension farm advisors in every county who provide valuable assistance to farmers, both in irrigation and crop management, and Resource Conservation Districts that offer assistance for irrigation efficiency improvements at the county level, he said. The National Resource Conservation Service, formerly the Soil Conservation Service, gives out millions of dollars a year for suppliers to make improvements in their irrigation systems through EQIP grants, he said.
Mr. Brostrom said the state has a number of grant programs aimed at the water-supplier level including Prop 13 and Prop 15; in Prop 1, there's $100 million for both Ag and urban water use efficiency, and this year, there's $19 million available through the AB 32 Cap-and-Trade Auction funds.
The 2009 water reform legislation included requirements for agricultural use efficiency in SBx7-7. Mr. Brostrom explained that the legislation has three components to it:
1-Large agricultural water suppliers serving 25,000 acres of more are required to submit an agricultural water management plan to the Department every five years. The first set of those were submitted in 2012, and the second set will be due at the end of this year, he noted. “Roughly 56 suppliers across the state were required to submit. In 2012 we received plans from 40 of those,” he said. “2012 was the first yearm so we anticipate receiving a much higher percentage this year.”
2-Large agricultural water suppliers serving 25,000 acres or more are required to measure farm-gate deliveries within their district. “This is a big requirement, and there are some big costs to do that,” he said. “I had a call from District in the San Joaquin Valley wondering about Prop 1 funds that has 4,000 turnouts or farm gates. They're estimating that it'll cost them roughly $40 million to implement that, and their annual budget is $11 million. So they're very interested in grants and loans to make that happen.”
3-DWR was directed to develop a methodology to quantify agricultural water use efficiency. “We completed that in 2013,” he said. “That's a report that's out there and available.”
Mr. Brostrom then discussed some statewide considerations with agricultural water use efficiency. There is a correlation between plant water use and crop productivity, he said. “The plant leaves have stomates on them, and it is through the stomates that plants breathe,” he said. “They take in carbon dioxide. But that's how they release water, water vapor, to cool themselves off. It's the same pore. So when plants are stressed, they close those stomata, and carbon can't enter. That stops growth and that stops production, so in general, if you try to stress or cut back transpiration on your crop plants, you're reducing yield.”
“There are some crops where that works, but that's almost specifically where you want a smaller plant, wine grapes being the clear example,” he continued. “Wine growers do not want a big bushy vine. They want small berries where the sun can get in and not let them get moldy or let the humidity build up in that canopy. There, they’re going after the price of those berries because although the yield of grapes goes down, they get a higher price for these stressed, restricted vines. And so that's one crop where deficit irrigation really works.”
“With most of our crops, you see a direct reduction in yield as you reduce the water use,” he said.
Water is really only lost from the system through evaporation or when it flows to salt sinks, Mr. Brostrom. “Recoverable loss is tailwater, which gets picked up by another grower. So on a watershed basis, you may have a farm that's at 50 percent efficiency, but because that water gets reused all the way through, basin-wide it can be up into 90 percent when you look at it as an entire watershed,” he said. “Also a lot of groundwater is recharged from agricultural irrigation. That water is moving back down into our aquifers and is available for reuse again.”
Water use efficiency projects provide other benefits besides water savings, he said. “In some cases you can have energy reductions, depending on the kind of embedded energy in your water supply. It takes energy to pressurize water for drip systems. If you're pumping water from the Delta to San Diego, you definitely cut down your energy use by going to drip. It's not so clear up near Chico, where a lot of it's gravity-fed.”
“There are also huge increases in productivity from going to drip or agricultural water use efficiency,” he said. “Better management generally yields better yields and labor savings as well.”
CLAIRE O’CONNOR, Natural Resources Defense Council
“We're still in the midst of a very extreme drought. In fact, 94 percent of the state is still in severe drought or worse,” she began. “As tough as the drought has been on all of us, and on farmers especially, it's not like we didn't see it coming.”
Back in 2009, the legislature passed SBX7-7, the Water Conservation Act, which asked large irrigation districts to do three things to make themselves and their customers more resilient to dry weather. “The first is they were supposed to adopt a plan to help them come up with strategies to deal with dry periods and describe which efficiency practices they were using,” she said. “Second, they were supposed to start measuring deliveries to their customers. And third, districts were also supposed to start charging their customers based on the amount of water that they're using, instead of using a flat rate or a per-acre rate fees.”
After the first round of water management plans were due, NRDC partnered with the Pacific Institute to take a look through the plans to see some of the different strategies that different districts had come up with. “We thought we'd kind of look through, kind of compare and contrast what each district was doing, but this proved to be more difficult than we thought, because at the time, there were just a handful of districts that had turned in their plans so we really didn't have much to compare and contrast,” she said. “Even now, more than two years after the plans were due, we're still waiting on almost one in five plans.”
“Similarly, of all the districts that actually did turn in a plan, about 17 percent actually state in their plan that they're not measuring deliveries, and they don't even have a corrective action mentioned in their plan,” she continued. “And finally, almost one in four stated in their plans that they're not pricing volumetrically, and again, didn't mention a corrective action plan. So for these districts, the Water Conservation Act really wasn't much help during this drought.”
“Another challenge to building resilient farms in California is that although we've made some improvements, we're actually lagging behind some of our peers in terms of irrigation technology,” she said. “Over half of California's irrigated acres are still irrigated using gravity systems. That's not to say that gravity systems are always bad or never the right fit, but other relatively dry, ag powerhouse states are more in the 20 percent range for gravity systems.”
“Similarly, 5,300 California farms are irrigated based on a fixed schedule,” Ms. O’Connor said. “Timing your irrigation to when the crops actually need the water can be a huge benefit for crop productivity and for water efficiency, so this is another challenge that we're facing as a state.”
“These two numbers are really related, because modern systems, such as drip or the microsprinklers, work best when water can arrive to a field pressurized and more on-demand,” he said. “So until the irrigation districts deliver water that way, it's going to be really tough for farmers to convert more away from gravity and toward the lower-flow systems.”
“The upshot of lagging behind our peers is that means that we have a huge opportunity to become more efficient in this state,” she said. “Now this isn't going to solve all of our problems, but NRDC wanted to take a look at what was our potential. And so again we partnered with the Pacific Institute last summer to take a look at several different sectors where we thought we had some untapped potential to become more efficient, including agriculture and we found that we actually had a great opportunity.”
1-Irrigation scheduling: “We looked at improving irrigation scheduling, which is timing the water for when crops most need it. This can both reduce water applications by about a third and improve yield and productivity.”
2-Drip and low-flow sprinklers: “We looked at increased adoption of drip technology or the low-flow sprinklers, as opposed to gravity irrigation. Drip irrigation in particular can reduce applications by about a quarter while increasing yield.”
3-Increased regulated deficit irrigation: “That's when you strategically withhold water during key stages of growth, usually to concentrate flavors in your fruit or in your nuts that you're growing. This technique can improve the quality of the fruits that you're growing and allow farmers to command a higher price.”
“We found that increasing the adoption of these three techniques could result in a 17 to 22 percent increase in efficiency, and in 5.6 to 6.6 MAF a year in savings and demand reductions,” she said. “To put that in context, a million acre-feet a year is roughly enough water to provide two million families with water for a year.”
She also pointed out that 5.6 to 6.6 MAF is also roughly the same amount of water that UC Davis estimated that farmers were short in surface waters this year. “This speaks to the power of increased efficiency as a drought resiliency tool,” she said.
“Efficiency also tends to be good for farmers' bottom lines,” she said, displaying the same graph as Peter Brostrom before her, and pointing out that it tells an interesting story. “It shows how our mix of irrigation techniques has changed over time in this state. And we have seen a decline in gravity irrigation and an increase in the drip and microsprinklers, though we can still do more.”
Ms. O’Connor noted that over this same time period, there has been economic growth in our agricultural sector. “Our farmers are producing more crop per drop, which speaks to the power of efficiency as an economic tool for farmers,” she said.
“Some people have criticized our findings, because not all of our savings represent new water,” she said. “In other words, because water is used in the ag context several times before it's ultimately consumed, improving on-farm efficiency doesn't automatically create more water for downstream users. However, that wasn't our goal. We weren't simply looking to figure out how much new water we could create when we undertook this analysis. Our goal was to see whether we could find a way to make water more reliable, more timely and more appropriate.”
“In fact, water efficiency offers significant potential to achieve these goals, and provides a whole host of benefits to farmers, communities and the environment, including improved water quality and reliability and usually lower energy costs to pump water around, to name a few,” she said. “Focusing too much on creating new water ignores these additional benefits of efficiency, especially for farmers.”
Ms. O’Connor then gave the example of how South San Joaquin Irrigation District has taken advantage of the multiple benefits of improved water use efficiency. “A few years back South San Joaquin converted a stretch of unlined canal into a pressurized pipe system that could provide water when farmers requested it, and it worked well with drip sprinkler systems,” she said. “This was a big shift for the district, and they weren't sure how their growers would react. They thought they might get 30 to 40 percent of their growers interested in the new system.”
“But it turned out that growers loved it,” she continued. “Nearly everybody wanted to sign up. So South San Joaquin was better situated to weather the current drought, and that has actually reduced groundwater pumping within its borders, because the farmers in the district need so much less water that they're not supplementing with groundwater. The new system was so successful that South San Joaquin is now even considering converting parts of its main canal to the new system. This is just one example of the multiple benefits of water efficiency in action.”
“So to wrap it up, this drought's not over,” said Ms. O’Connor. “And it's not the last dry time that we're going to see in this state. Although the Water Conservation Act gets us started on a path towards resiliency, we have a long way to go, both in implementing the current law and in going beyond to modernize our irrigation system.”
“The good news is that improved efficiency is possible and can play a role in offering a whole host of benefits for the state,” she said. “Conservation and efficiency is not a panacea, but it can go a long way quickly toward making our food system more reliable.”
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MARK ATLAS, Downey Brand
Mark Atlas began by saying that he lives in Willows, an agricultural community located halfway between Sacramento and Redding on the west side of the Sacramento River. His clients are primarily contractors with the Central Valley Project on the Tehama-Colusa and Corning canals; a few of his clients have pre-Central Valley Project water rights, and hold Sacramento River Settlement Contracts.
There has been farming in the Sacramento Valley since the mid-19th century, irrigated farming for over 100 years now, he noted. “I'm going to frame agricultural water efficiency this way,” he said. “I'm speaking mostly of the Sacramento Valley today, but I see friends who represent water agencies and farmers in the San Joaquin Valley, on the west side in particular, where the same concepts apply.”
Mr. Atlas noted that in 2014, water service contractors from the Central Valley Project received 0% of their Central Valley Project contracts. “Water use efficiency, conservation, and careful management of water is a religious tenet for those people because this happens. In other years, we've had 25 percent supplies, sometimes 100 percent. This drought that we're suffering right now is not the first one, and it won't be the last one.”
“Reasonable beneficial use of water is a basic foundation of water rights in California,” he said. “Agriculture is recognized as a beneficial use of water, both in regulations of the State Water Resources Control Board and also by the courts.”
Mr. Atlas then discussed the practical aspects of what farmers have been doing.“Between 1967 and 2010, production is up 88% on 20% less water,” he said. “The economic efficiency of agricultural water use has more than doubled in the same period, from over $600 per acre foot to $1,500 per acre foot.”
In that same time period, the cost per acre foot of water from Colusa County Water District was $2 an acre foot; in 2010, it was $65 an acre foot — 3,250% increase in the cost of water. “In the same period of time, production's gone up, and water use has gone down,” he pointed out.
“How do we do it in the Sacramento Valley? One of the basic principles is use it, reuse it, reuse it, reuse it,” he said, presenting a depiction of the Sacramento Valley’s water use produced by the Northern California Water Association. “Shasta and Trinity reservoirs are at the top end, and as the water comes down the river, it's diverted at various places for various crops and other uses.”
“Rice is a big crop in the Sacramento Valley and it has been since the turn of the century,” he said. “Rice farmers are the best-ever example of use, reuse and reuse. Water is diverted into one farmer's rice field, and a portion of that flows through to the next farmer's rice field and on and on and on. And then it's returned to the river. There's no quality issue with the water when it's taken by the farmers. It doesn't have to be filtered or treated or anything for the next farmer to pick it up.”
Mr. Atlas noted that some people say it takes 6 or 7 feet per acre to farm an acre of rice in California in a desert. “If a farmer fallows an acre of land to transfer water, the Department of Water Resources and the Bureau of Reclamation say that frees up 3.3 acre feet of water,” he said. “So the real net use of water for rice on average in the Sacramento Valley is about 3 acre feet per acre, not a whole lot different than a lot of other crops that are growing.”
Mr. Atlas noted there are no saline sinks in the Sacramento Valley. “The water that's not evaporated by the plants and isn't returned to the river as surface flow percolates into high-quality groundwater aquifers where it's picked up by others. … it is picked up by a lot of farmers in their groundwater wells to keep their crops alive during the year when surface water flows are reduced.”
When the water gets back to the river, it goes to Sacramento where they take it out and drink it, he said. “Sacramento city's water supply is pumped from the Sacramento River after all my friends and neighbors up the river have used it and reused it and reused it.”
“Sacramento Valley's called a self-conserving basin, and you can see why,” he said. “One of the things that water agencies and farmers do is maximize the management of their water. The water agencies that I represent, on the Tehama-Colusa Canal at least – are fully underground piped, with metered deliveries using the pressurized systems that Claire talked about earlier. Not necessarily on-demand deliveries, because on-demand deliveries, meaning I get it when I want it like when we turn the tap in our house — very expensive systems to build, so almost every system, whether canal, surface canals or underground pipeline for agricultural use, has some rotation built into the design, because we just can't afford to build systems that are fully pressurized all the time for every single one of those farmers.”
“In any event, though, farmers are doing what they've been asked to do and what they need to do in order to survive,” he said. “There's less and less tailwater, primarily because of the shift of crops … the amount of water that runs off of fields now in the Sacramento Valley is a small fraction of what it was even when I started practicing.”
There has been a move to high-efficiency irrigation techniques, he said, presenting the same chart as the other two panelists and noting the dramatic reduction in the amount of flood irrigation. “We've already heard, too, that not all flood irrigation is by definition bad,” he said. “Sprinkler irrigation, the sort of traditional sprinklers is the red line and it's going down, and what's really taken off in the last few years is the green line – the drip and micro-sprinkler.”
Mr. Atlas pointed to the purple line, which represent subsurface irrigation techniques. He had an example of new drip tube with the emitters built in on the inside. He noted that the emitters are pressure-regulated, so that the trees at the top end of the field get the same flow rates as those at the bottom end of the field.
“Sometimes this is laid on the top of the ground, sometimes it's buried below at the root zone,” he said. “Some farmers order this with the emitters at the same spacing as the trees, and then they lay the tree grids out by GPS, so every tree gets its emitters, and there are no emitters in between the trees. It's pretty amazing actually to see it planted.”
Mr. Atlas noted that one of the costs associated with it is that the fields have to be worked with equipment that has GPS equipment in it to prevent it from being damaged.
“Microsprinklers have different flow rates and different patterns,” he said. “There’s one at every tree, and then the heads can be changed over time as the trees develop.”
Mr. Atlas concluded with a picture of Jane Johnson’s ranch, where his Grandpa George and his wife arrived to farm in the Sacramento Valley in 1912. “His wife looked out her kitchen window one day, not too long after they'd moved from Illinois, to see what? Mount Lassen erupting. And she wanted to know where the hell George had brought her to,” he said. “But they stayed, and they farmed all kinds of things over time — turkeys, row crops, clover for seed. And a few years ago, the cousins who now operate this, acquired this ranch when their aunt died, it's about 40 acres. And last year they planted a walnut orchard. They had a solid set sprinkler put in, … Every one of those sprinklers will serve a tree. And then as the tree grows, they change the heads to change the patterns, change the flow rate, so that the water is enough to serve the tree, but not anything else.”
Mr. Atlas then gave a few closing thoughts. “In the Sacramento Valley, we've lived with scarcity historically – we have in the past and we will in the future,” he said. “Efficiency is a way of life, and the things that you see here and that I've talked about are things that the farmers have implemented without government intervention.”
“Now sure, government policies have partially contributed to the big zero allocation,” he said. “It's a fact of life. But with respect to people who do this kind of stuff, the government's not telling them to do it. They're doing it because they need to do it; it's the right thing to do. It's the right thing to do economically, it's the right thing to do because they're stewards of the land, and they consider themselves that for their families and for what they do.”
“The last thing is when you think about agricultural use of water, it's really use of water for people,” Mr. Atlas pointed out. “What do we do with it? We grow stuff for you and me. And in the case of the Sacramento Valley, we're growing it in the backyard of the Bay Area. … what happens if we don't grow almonds in California? Where do we get them? The next nearest place that produces almonds is Turkey. So we can talk about carbon footprint, all the rest of that stuff, and food safety and those kinds of considerations, so we have to think about that.”
“Farmers that are our friends and neighbors are producing the stuff that we want them to produce right where we want them to produce it,” he concluded.
Questions and answers
The floor was then opened up for questions.
The question was asked if the panel could comment on the relationship between Prop 218 and volumetric pricing.
Prop 218 is the set of statutes that establishes procedures for getting rates and charges – in this case, water, responded Mark Atlas. “We do it. It's just a fact of life. The water districts that I represent, when they raise their water rates, when their water rates go up, we just have to do it. It requires notice to every property owner in the district of what the rates are going to be. They have 25 days to see if there are a sufficient number of protests. If there aren't, then they can increase the rates. And if there are a sufficient number, they have to wait a year. I'm proud to say we've never had to do that in any of the districts that I represent – and we're pricing water volumetrically.”
Claire O'Connor added that when they were reviewing ag water management plans, they talked to the water districts. “It's certainly a challenge, but I think that Mark's right that the districts that had success with working through the Prop 218 process really engaged their constituents and talked to them about it early, about why these changes were needed. So some of the districts that we talked to we had good success with that transition, despite Prop 218.”
“There were some concerns from some of the districts, where they were going to add these increased costs to install metered farm gauges, and that they would have to raise their rates to make that happen,” added Peter Brostrom. “They thought might lose a Prop 218 election to do that, and then they would be caught in a pickle of not having the funds to implement that requirement. And so that's definitely been expressed to the department on that regulation, the Prop 218.”
The question was asked what percentage of the top crops — almonds, pistachios, alfalfa — exported from California?
“Eighty percent of almonds are exported,” replied Peter Brostrom. “So a big bulk of them are exported around the world. Alfalfa, it's 10 or 15 percent that get sent to Japan. The other big crops — processing tomatoes, a lot of that gets exported. Corn is all used locally when the price is high. We import a lot of corn from the Midwest because there are more profitable crops that we can grow here. … We can go through a whole list of crops where we are the world's or the nation's leading producer, so from our lettuce in the Salinas Valley, the Imperial Valley …I would say a larger percentage of our crops are exported, because we have such unique growing conditions. And we grow such a wide variety of crops.”
“Sometimes people ask that question so they can then say ‘what that means then is we're exporting our water to China,’” said Mark Atlas. “The Chinese market is a big market right now for almonds, less this year than in the past. The Chinese are sending us a few million of these [cell phones] every week. The economists will tell you that balancing your trade is an important thing for a country to do. So that's one opportunity to help do that.”
It was noted that both Mr. Atlas and Mr. Brostrom mentioned that there was some element of flood irrigation that was percolated into groundwater and was then used. Is there a metric that's been adopted or revised to evaluate how much is actually reused? And if so, what's the range of efficiency for groundwater recovery from flood irrigation?
“I think it varies widely across the state with the irrigation method and sort of the level of precision of irrigation scheduling,” said Peter Brostrom. “Some growers will, if they're deficit-irrigated, have no water movement through that root zone. In fact, the trees are mining soil moisture from that winter. … The regional plan for the Feather River area, includes a large number of rice districts, and they estimated that for every acre of rice that was grown there, there was a half-acre of water that was deep-percolated for the groundwater table.”
The question was asked if there was a movement in agriculture to change crops or change varieties to save water?
Mark Atlas said that one thing that’s done is that the rice industry funds a rice research station in Richvale. “One of the things that they've done is they developed what they call ‘short-stature rice.' So I don't know this from my own knowledge, but in the '50s and '60s, the rice stalk was quite a bit longer, taller. It's much shorter now, which does two things. First of all, you don't have to flood the field as deeply, and there's not as much plant material as [unintelligible], plant material to evaporate moisture. So that's one.” He also noted that UC Davis does a lot of research on producing the same amount of produce with less water, looking at the varieties of crops that are grown.
“Sorry to correct the attorney here a little bit,” said Peter Brostrom. “You’re changing the harvest index, so if you're looking at carbon in a plant, a higher percentage is going to your rice kernels as opposed to the stalk that was used to grow it. And they're then grown on a shorter season. It used to be typically rice season would go into November. And now Labor Day weekend, there are harvesters out there, which is decreasing the amount of time that the fields are flooded and then the amount of water that's being used.”
“Mark referenced the famous 3.3 acre-feet that DWR provides for transfers of rice water,” Mr. Brostrom continued. “I think we're doing studies now to look at that number and evaluate it, because cultural practices have changed so much over time. But I think, to Mark's point, is as you're producing better yields through better crop management, better fertilizer practices, managing your land, all those efficiencies add up to a better use of water. You get more productivity for that amount of water use.”
Moderator Katy Spanos then closed the gave a concluding thought. “Going back to the California Water Plan … It says the plan recognizes and reflects five things every Californian should know about water. I think they're really important, and I just want to make sure we all kind of think about them as we leave.”
“The first is that water is the essence of life for California,” she said. “The second is that California's complex water system is in crisis. The third is that a diverse portfolio approach is required. The fourth is that solutions require integration, alignment and investment. And lastly, we all have a role to play in securing our future.”
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