Groundwater problems and prospects, part 7: Groundwater-dependent ecosystems and the groundwater-surface water connection

GW Dependent Ecosystems SliderboxMaurice Hall, Thomas Harter, and Professor Richard Frank discuss the connection between groundwater and surface water using examples from the Central Valley and the Scott River Valley to illustrate their case

This year’s California Water Policy Seminar Series, presented by the UC Davis School of Law and the Center for Watershed Sciences, focused its attention on the issues and challenges surrounding implementation of the new Sustainable Groundwater Management Act. The legislation, signed by Governor Brown last fall, set in slow motion a process to regulate most of the state’s groundwater basins.

In this lecture, Maurice Hall, Thomas Harter, and Professor Richard Frank focus on groundwater-dependent ecosystems and the connection between groundwater and surface water as illustrated by the Scott River Valley groundwater litigation.

Today we’re going to talk about groundwater-dependent ecosystems and about something that the hydrologists certainly know already, and that is that it’s difficult as a matter of hydrology to talk about groundwater in isolation because there are some significant links to surface water flows and supplies,” began Professor Richard Frank. “The scientists and the engineers know that, but our legal system continues, for the most part, to think of groundwater and surface water sources as distinct entities, and treat them differently. The 2014 Groundwater Legislation made some very modest inroads into that disconnect, if you will.

MAURICE HALL, Water Program Director for the Water Funders Initiative; formerly with the Nature Conservancy

Maurice Hall
Maurice Hall

Professor Frank introduced the guest speaker, Maurice Hall, who recently became the Water Program Director for the Water Funders Initiative, a collaborative effort to identify and track funding for the most promising solutions for the problems of water scarcity and reliability in the United States, with at least an initial focus on the American West. Prior to that, Maurice Hall worked for the Nature Conservancy here in California, eventually serving as the science and engineering lead for TNC’s California Water Program.  Mr. Frank noted that his work at the Nature Conservancy included helping to shape and help pass California’s landmark 2014 groundwater legislation.

Mr. Hall began by saying that groundwater legislation was something he’s been working towards for a long time and that it’s not just about the groundwater, but it’s about how groundwater management or the lack of management impacts and undermines the surface water supplies.

You’ve probably heard factoids about groundwater being about a third of our water supply, and surface water being the rest of it,” he said. “But in fact, groundwater is even more important than that because it does underlie and at times certainly supplies part of the surface water. Pumped groundwater affects the surface water, and I’m going to talk a little more about that in detail. So I’m titling my talk ‘Groundwater/ Surface Water interaction and the Status of that Connection in the California Central Valley,’ because we, at the Nature Conservancy, did some work to really try and illuminate the issue in the Central Valley.

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_02He then gave a quick overview of the basics of groundwater. “Mostly when we talk about groundwater in California we’re talking about these valley fill aquifers which are basically any flat place in California,” he said. “You’re standing on a valley fill aquifer if you’re standing on a flat place in the Central Valley, the Napa Valley, Santa Clara Valley down south, the LA Basin – those are valley fill aquifers where sediment is filled in between surrounding hills. Most of those have some water in them, and in fact, in California, most of the time that water is usable.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_03He then presented a map of the aquifers that are delineated by the Department of Water Resources. “90% or more of our groundwater is pumped from these basins,” he said. “Sometimes we have basins and sometimes we have sub-basins. Sometimes the delineations between the basins that make the sub-basins really are meaningful and sometimes they’re really not very meaningful. But in the Central Valley that’s particularly the case in that there’s no hard boundaries between the sub-basins.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_04He then presented a map from the California Water Plan showing overall water use in California, and how much of it is groundwater. He noted that the state is divided into eleven hydrologic regions, and the tall bars show the total water use in that region. “When you have a really tall bar, that means that the total water use there is really big. The smaller bar represents the fraction that is supplied directly by groundwater, so that just means it’s what’s pumped out of a well,” he said. “In the Central Valley, there is a huge amount of water use. In the northern part of the Central Valley a smaller fraction of that is groundwater; In the southern part of the Central Valley down in the Tulare Lake basin, Fresno and Bakersfield, a much bigger percentage of the total water use comes from groundwater.”

Mr. Hall noted that other parts of the state use much less water. “For instance, in the Central Coast, there is a much smaller amount of total water use, but nearly all of it is groundwater,” he said. “Part of the reason for that is that there is very little reliable surface water flows in rivers and streams there and so long ago we turned to groundwater as the main water source in those regions.”

A total of about 15 million acre feet of ground water is pumped in California,” he said. “A million acre feet that will provide water to about two million households, and so that’s a huge amount of water. I’ve heard it said that California pumps more groundwater in a year than all of the rest of the nation combined. I haven’t seen the original source of that, so I’m a little skeptical, but we definitely pump a huge amount of groundwater and most of it is here in this Central Valley. And 80% of Californians rely on groundwater for a part of their water source.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_05He then turned to groundwater overdraft in the Central Valley. “Groundwater overdraft basically means you’re taking more water out of the groundwater basin than is being recharged,” he said, presenting a chart of change in groundwater storage produced from the Department of Water Resources Integrated Groundwater and Surface Water Model in the Central Valley. “This is a model that’s accessible to anyone. It really represents our best picture of the total water use and how the groundwater and surface water are interacting in the Central Valley.” He noted that the USGS has built the Central Valley Hydrologic Model that gives similar results.

Mr. Hall explained that the narrow lines going up and down show the annual groundwater pumping amounts. “In dry years, you pump a lot more; in wet years, you don’t pump as much,” he said. The heavier lines, which are in different colors representing different regions, represent the 10-year moving average, which shows the trend of groundwater levels, he said. “The Tulare Basin is the green line … this trend down means that more water overall has been taken out than is being recharged. In the case of the Tulare Lake basin, more than 100 million acre feet of water has been drawn out through the years than has been recharged.”

The other parts of the basins, such as the San Joaquin, it is not quite as dramatic, something like 20 million acre feet over the last century,” he said. “And this yellow line represents the Sacramento Valley which most folks think of as being reasonably healthy. The groundwater levels aren’t plummeting like they have in other parts of the Central Valley, but in fact, the groundwater levels have declined through time and it’s had some pretty significant impact to with respect to surface water that I’ll describe to you in just a little bit.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_06He then presented a slide showing how far groundwater levels has dropped from between 1925 and 2009, noting that this is from the same model but it’s just another way of looking at the information. He explained that the reddish areas show the areas where the groundwater levels have gone down several hundred feet. “There are places where the groundwater levels are more than 500 feet lower now than in the 1920s and ’30s, and this is just evidence of the huge amount of pumping, the overdraft, and the long term downward trend of water levels.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_08He then turned to the groundwater-surface water connection, the main topic of the discussion today. “This is a picture of the Cosumnes River, which is a small river in southern Sacramento County, that flows year-round out of the mountains,” Mr. Hall said. “Once it gets out on the Valley floor, it flows over this big Central Valley alluvial aquifer. It’s a big flat Valley, so there’s probably groundwater under it. In fact the groundwater levels have been drawn down under the Cosumnes River to the point where now every year, all of the water that flows out of the mountains sinks into the ground beginning about July 4th or so, the Cosumnes River goes dry in the lower 10 or 15 miles. And it stays dry well into the fall because those groundwater levels have been drawn down.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_09Anytime you see a river flowing over a valley in California, there is almost certain to be groundwater underneath, Mr. Hall said. “In a natural state, before we pump and we lower the water levels, the groundwater tended to flow out into the rivers because that was the lowest point, so the basin basically filled up until it got full enough to start oozing out, and it oozed out at the lowest points along the streams,” he said. “So under natural conditions without pumping the groundwater, most streams tend to gain water from the groundwater. That’s really the only reason we have stream flows unless there’s a dam upstreamThe only reason we have stream flows likely here is because the groundwater is oozing out of the ground into the stream and contributing to stream flow.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_10When we pump wells, we basically lower the water level from the wells, and that lowers the water levels in the surrounding areas,” Mr. Hall said. “If you have a lot of different wells, you can lower the water levels over miles and miles and miles of aquifer, and that is what’s happened in the Central Valley. When you do that and the groundwater levels in the surrounding areas are lower than the stream, the stream loses water to the groundwater. The water flows downhill even in the ground.”

He pointed out that the illustration shows that the stream is losing water to the groundwater, and conversely, the groundwater is being recharged by leakage from the stream. “This happens all up and down the Central Valley, and it happens in the Salinas Valley and it happens in the Santa Clara Valley where streams are flowing over the surface and there’s a fair bit of groundwater pumping, recharge from stream leakage is an important source of the recharge that keeps the aquifer levels from going down faster than they would otherwise.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_11You can get to a point where groundwater levels are drawn so far down that it becomes disconnected from the stream, he said. “When it gets disconnected, it doesn’t matter how much further you draw the groundwater level down; the stream’s just going to leak as fast as it can leak through the sediments. This is a situation that we have in parts of the Central Valley, particularly down in the southern part.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_12The stream will go dry if the leakage rate exceeds the flow, so if the flows get low during the summer and the stream doesn’t have a lot of flow in it, it will leak into the ground,” he said. “This is basically how the groundwater/surface water interaction works when you have streams flowing over these alluvial aquifers.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_13He then again presented the slide showing the difference in water levels in the Central Valley, noting that in the southern part of the valley, groundwater levels have been drawn down 200-300 feet. “These streams flow year round out of the mountains often because they’re supplemented because of reservoir releases, but once you get a little ways out on the Valley floor, those beds are dry and almost never flood: The Kings River, the Kern River,” Mr. Hall said.

Further north in the Central Valley, there are a lot of streams still connected to groundwater, said Mr. Hall. “It’s the fundamental reason that I was so adamant in the groundwater legislation that we not ignore the interaction between surface water and groundwater,” he said.

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_14Let’s assume you have a groundwater basin where you’ve had pumping for a long period of time and you’ve had an equilibrium established,” he said. “So the recharge equals the pumping rates, and so the groundwater levels aren’t going down any further. Part of the reason that you can pump some groundwater out and not continue to lower the groundwater is that the river leaks and recharges the groundwater.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_15Let’s assume that this is the case for a number of years,” he said. “Then we increase the pumping and put some more wells in, and we draw out more groundwater. It lowers the groundwater levels for a while so for a little while you’re in overdraft condition, you’re drawing out more water than is being recharged but, what happens in this case when you still have a connected river, you have a steeper groundwater gradient away from the stream, so the stream leaks more and it contributes more recharge. You could in fact imagine that even with this increased pumping, after a little while a new equilibrium is established that does have more recharge now supplementing that groundwater and replacing the water that’s withdrawn.”

That comes at an expense,” said Mr. Hall. “It’s not new water that’s magically formed; it’s water that’s being taken out of the river and these rivers and streams are somebody’s water supply. They may be water supplies for fish and wildlife, but they’re also the water supplies for the City of Sacramento perhaps, and the export pumps that take water to Southern California and the state and federal water projects, and were needed for some delta outflow to try and protect endangered species in the Delta.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_16When you increase this pumping and draw the groundwater levels down, you draw in more water from the surface flows, and that means that there’s less flow in the streams,” he said. “And if you draw it down further, you also have issues with wells going dry when you lower the water levels. You draw it down further and the stream is still connected, you further increase the rate at which the stream lends its flow to the river.”

This is really important, not just for groundwater management for the reliability of surface flows, Mr. Hall said. “We did some work with this same model to estimate how much of a difference does it make in the Sacramento Valley, because it’s the biggest source of freshwater supply in the state,” he said. “It’s the main source for the Central Valley Project and the State Water Project that supplies part of Southern California, so if it’s affecting Sacramento, there’s a lot of people who’d care.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_18He then presented a plot showing the net stream gain and loss for the Sacramento Valley. “In some cases you have stream reaches and the alluvial aquifers are losing water to the groundwater, and in some cases because recharge is high in areas, you have reaches of the stream that are gaining water,” he said. “So this plot shows on the whole, for the Sacramento River and all of its tributaries, how much water was the Sacramento in the valley floor once it leaves then, gaining or losing to the groundwater.”

Mr. Hall explained that the ‘tipping point’ is the point where the river becomes a net zero; it’s losing as much to the groundwater as it is gaining from the groundwater. “We think that that happened with the Sacramento River probably in the last 15 years or so,” he said. “So back in the 1950s and ’60s, the Sacramento River and it’s tributaries were probably gaining about a million acre-feet per year on average from the groundwater. So that means in addition to the water that was released from the reservoirs or that flowed out of the side stream, another million acre feet per year was contributed to the flow of Sacramento by groundwater pumping and by groundwater inflows to the river.”

As pumping progressed through the years, the groundwater levels were drawn down some, but not a lot, Mr. Hall said. “Overall, it reduced the amount of water that was flowing from the groundwater into the Sacramento River tributaries, to the point where around 2009 when this model ended, we’re pretty much at a net-zero. That means a million acre feet per year on average, maybe it was 700,000 to 1.4 million – a pretty good bit of water. There was less water in the river than there would have been without groundwater pumping.”

Mr. Hall said they then did a model run, keeping the same rates of pumping, reservoir operations and other conditions the same as today. “The impact from the pumping that is occurring today hasn’t reached the river yet,” he said. “So in 10 – 20 years from now, there’s going to be even less flow in the Sacramento River than there would have been because of the pumping that’s happening today. You’ve probably heard from Dr. Fogg earlier about how with groundwater hydrology, it takes a while for the impacts to move through the aquifer. And that’s the case here; the impacts from today’s pumping haven’t even shown up yet in the river.”

So something like close to a million acre-feet less water shows up in the Sacramento on average in a year than it did before pumping, and we expect that erosion to continue to the tune of something like 400,000 or another half million acre-feet at today’s level of pumping, but that is not reality anymore,” he said. “This model stopped in 2009. There are estimates that 200,000 new acres of land in the Sacramento Valley have been brought under irrigation since 2009. New orchards primarily, olives and almonds… And so not just today’s pumping, but that increased pumping is going to take years and perhaps even decades to show up at the river.

Mr. Hall said that this is why it is really important to manage groundwater to avoid, as the legislation describes, ‘the undesirable result of significant impacts to surface flows and beneficial uses of surface flows.’ “Because if we don’t pay attention and we don’t implement good river groundwater management, then the groundwater pumpers basically end up having a senior surface water right. Pump the groundwater and it’s going to be reflected in the surface water.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_19He then presented the same plot for other parts of the Central Valley, noting that basically what happened with the tipping point in the Sacramento River happened many years ago in the Tulare Basin and from the San Joaquin into the Central Valley.

[Slide 20] Mr. Hall then turned to other groundwater-dependent ecosystems, noting that other vegetation accesses the groundwater. “The forests and trees have roots that go deep enough to be able to access the shallow groundwater,” he said. “You have places where local lenses of perched groundwater that support unique habitats and these habitats depend on certain groundwater conditions. And there is riparian vegetation, and on the flood plains where you have wetland habitats. One of the reasons these habitats developed is because there’s high groundwater levels all the time. And so the vegetation that can depend on that water and need that water all the time can survive in these areas but they can’t survive further up the slope further away from the groundwater.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_21The Nature Conservancy did some work mapping where groundwater-dependent ecosystems occur across the state which is published in PLOS One. They mapped ground-water dependent wetlands, which are wetlands that have special groundwater-level needs.

One of the things required in the legislation is that groundwater management consider the impacts to groundwater-dependent ecosystems,” he said. “So one of the things that the Nature Conservancy wanted to provide is better information on how to assess these. One of the conceptual ideas to illustrate the importance is to take the map of the groundwater basin and shade it in according to the density of groundwater-dependent wetlands.”

Mr. Hall pointed out that generally, as you go north, you have more and more groundwater-dependent wetlands. “Part of that is because of the geography and the different weather conditions and part of that is groundwater levels have been drawn down in a lot of the parts of the state, so those wetlands no longer exist,” he said. “So if we want to see these wetlands persisting in the future, we’re going to need to thoughtfully manage the groundwater to prevent them drying out as they have in other parts of the state.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_22There are other groundwater habitats and natural systems that depend on groundwater besides the streams, which is shown in this map, Mr. Hall said. “The Nature Conservancy is putting together a database that you can access that provides a lot of digital information for spatial analysis of this kind of work, and it’s the kind of information that the Department of Water Resources, as they develop the guidance for implementation of groundwater legislation, are going to need to grow on.”

MHall_UCDavisLawClass10-19_-2-2015_v2_Page_24Mr. Hall closed with a picture of the Amargosa River, east of Death Valley. “The Amargosa on a map is hundreds of miles long, but it really only flows above the surface for about 15 or 20 miles in a few specific places,” he said. “At those points the groundwater rises to the surface and supports a year-round stream here where it’s 115 every day in the summer. So with that I’ll turn it over to my colleague. Thank you.”

THOMAS HARTER, Cooperative Extension Groundwater Hydrologist, Department of Land, Air, and Water Resources, UC Davis

Scott Valley 2015-03 - UCD GW Policy Series_Page_03Thomas Harter then discussed the Scott Valley groundwater case, and why it is interesting from a groundwater-surface water perspective.   The Scott Valley is in the far northern corner of California, close to the Oregon border, surrounded by mountains.

Scott Valley 2015-03 - UCD GW Policy Series_Page_04The watershed is about 800 square miles. The elevation in the Scott Valley ranges from 2,700 feet up in the Northwest corner where the Scott River flows out into the valley, to 8,000 feet in some of the mountains that are just to the west of the valley. The Scott River flows from the south to the north and out to the Northwest along the east side of the valley, he noted.

This is an interesting system for California as it’s a very shallow alluvial valley that was created by a fault which dammed up the Scott River and allowed it to sediment in the mountains and create the aquifer system in the floor of the valley, Mr. Harter explained, noting that today there is about 30,000 acres of agriculture on the valley floor.

Scott Valley 2015-03 - UCD GW Policy Series_Page_05He then presented a cross-section of the valley, pointing out that the bedrocks are very close to the surface. “There is somewhere between 100 and 400 feet of sand and clay sediment that have been silted in here by the rivers that come off of these mountains and filled up the area above the bedrock here and in the bottom of what are called ‘bathtubs,” he said.

Scott Valley 2015-03 - UCD GW Policy Series_Page_06He then gave a rough explanation. The bedrock is fractured and folded, and there is the sediment that’s been deposited by the river.

Scott Valley 2015-03 - UCD GW Policy Series_Page_07Recharge that comes from the flow from the rivers out of the mountains as well as precipitation fills the sediments in the groundwater and as the water fills the sediments …

Scott Valley 2015-03 - UCD GW Policy Series_Page_12It all comes out at the lowest spot.

Scott Valley 2015-03 - UCD GW Policy Series_Page_14And as it fills up some more, this water flows to the river.

Scott Valley 2015-03 - UCD GW Policy Series_Page_15The Scott River flows through the valley that’s about 20 miles long and 3 to 4 miles wide. “Early in its history we had gold mining at the southern end of this valley and dredge mining going on until about World War II, so much of the southern-most part of this valley is filled with old dredged hills,” he said. “We have a lot of ranching in and around this valley, and on the valley floor, we grow hay and alfalfa predominantly, and this has been the case for much of the 20th century and even late 19th century.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_17Much of this used to be flood-irrigated, where river water or canal water is taken and used to flood meadows, either pastures or alfalfa meadows,” he said.

Scott Valley 2015-03 - UCD GW Policy Series_Page_18There are a number of canals that divert water from the Scott River along the side of the valley to then flood meadows and pastures and alfalfa fields.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_20About half of the acreage here is alfalfa, and they harvest fairly high value alfalfa, two to three times per year,” Mr. Harter said.

Scott Valley 2015-03 - UCD GW Policy Series_Page_21He then displayed a map showing the cropping pattern and land use. He noted yellow is alfalfa, green is irrigated pasture, and the blue is non-irrigated dry land, and the brown is the dredge tailing from former mining operations.

Scott Valley 2015-03 - UCD GW Policy Series_Page_22In the 1960s to 1970s, a significant part of the valley converted from inefficient flood irrigation to more efficient sprinkler irrigation, he said.  “Most of the alfalfa that we grow in the valley became irrigated with sprinklers, and for these sprinklers the farmers turned to wells because they have to be pressurized anyway, and an easy way to pressurize this line is to sink the well into the groundwater aquifer into these sprinkler lines.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_23The wells are pumping the water table, creating depressions in the summer that is filled by recharge in the winter, he said. “This is going back and forth in the Scott Valley.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_24He then presented a slide of graphs from a number of wells showing water levels from January of 2006 to January of 2014. “You can see there’s annual up and down of water levels that doesn’t really change very much over time,” he said. “Most of these wells seem to be relatively steady, and even though over the last eight years we went through two droughts, the 2007 to 2009 drought, which is sort of in the middle of this graph, and more recently the 2011 to current drought which is on the right hand side, we really don’t see a major impact of that drought on these groundwater levels. What also has happened more recently is that many of these fields that used to be sprinkler irrigated are now on large center pivots which are even more efficient than the sprinkler lines.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_30He then presented a map showing how the different types of irrigation methods were distributed across the valley, noting that blue represents center pivot irrigation, orange represents sprinkler irrigation, and the green are flood-irrigated pastures, and in red are the irrigation wells that have been drilled over the last 40 years.

Scott Valley 2015-03 - UCD GW Policy Series_Page_31The research team used models to estimate how much groundwater is being pumped for irrigation, and he noted that a lot of the pumping happens relatively close to the Scott River throughout the valley.  “You may ask, “What’s the big deal here? What is the connection to this groundwater dependent ecosystem?

Scott Valley 2015-03 - UCD GW Policy Series_Page_32The Scott River is one of four tributaries to the Klamath River below Iron Gate Dam, and one of four rivers that salmon can access as a spawning ground coming from the Pacific Ocean, he said. “There is both a Coho-run and a Chinook fall run of salmon that are coming up the Scott River in the fall,” he said. “When flows increase, they come up here in the fall to spawn. The Chinook will leave in the spring, and the juvenile Coho will stay over the summer and then leave in the following winter. So summer flows are very critical for the Coho, and it’s those summer flows that are impacted by the groundwater pumping that we’re doing for the irrigation on the alfalfa.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_34He presented a graph of water levels, and noted that where much of the conflict in the Scott Valley arises is that the summer flows on the Scott River have been significantly lower in the last 30 to 40 years then what it was in the 1940s, 50s, and 60s. “The change in when we are seeing this extremely low summer flows, which is typically in August and September, really coincides with the switch from flood irrigation everywhere to having about half of the valley sprinkler-irrigated wheel lines and now center pivots,” Mr. Harter said. “One of the older wells that have been monitored for a relatively long period of time by the Department of Water Resources also is showing somewhat lower water levels perhaps reflecting the same phenomenon.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_36Mr. Harter then presented a chart of average summer streamflow as measured by a USGS, noting that it was just for the period May through September, which is the critical flow period for fish. “We can see that in the 1940s to the 1960s, that low-flow tended to bottom out at about 60 cfs,” he said. “If you take the last 20 years, that low-flow ended up at about half as much or about 30 cfs.  That’s a significantly smaller amount of stream flow.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_37Some of that decrease has been explained in a recent paper where statistically this watershed was compared with the other three watersheds that are in the Klamath Basin; about one third of that decrease has been shown to be due to climate change,” he said. “One of the interesting aspects of this is actually that the 40s and 50s weren’t exactly the driest time; these earlier records that we have for the Scott Valley in the 40s and 50s show that it tended to be a relatively wet period. We had some dry years like the 70s again around 1990, and most of the last 15 years were relatively dry. We’ve also had very low flow periods in the 1920s and 1930s; there are in fact newspaper articles that talked about the Scott River being completely dry in the late 1920s.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_39So the stage is really set for conflict between agricultural pumping and the environment, where we have endangered species, the public trust doctrine, the Clean Water Act, and the fisheries, both the Native Americans who use the fishery downstream as well as the commercial fishery, with the Scott River in the middle of it, Mr. Harter said.

“The part that we have been contributing to this is that we’ve been developing modeling tools to better understand the system and the hydrology in the systems, and to work with the state over in the Scott Valley and help them understand how the system works and what potential groundwater management practices may actually improve the stream flow situation in the late summer,” he said.

Scott Valley 2015-03 - UCD GW Policy Series_Page_43They’ve put together models that look at water budgets, recharge and pumping, and how pumping is impacted by pumping patterns, as well as a 20 year groundwater model that shows the impacts of both wet and dry years on the overall budget, he said.

One of the things that we’re finding is when we used textbook values for irrigation on alfalfa, the irrigation amount that we calculate is actually much higher than what growers report and farm advisors measure for irrigation in the valley,” Mr. Harter said. “It turns out that they are actually super efficient in the irrigation of the alfalfa. It’s part of the research project. We are finding that they are using much of the soil moisture storage in the valley for their irrigation, which is highest right here along the river. They actually use soil moisture storage from winter and spring for much of their summer irrigation.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_48We need to have more water in the aquifer in the summer when the base flow occurs in order to increase streamflow, so the model is being used to look at the key alternatives, he said. “To increase the amount of groundwater storage, one of the alternatives that we’re looking at is to use surface water instead of groundwater for irrigation until there is not enough surface water to do that, which would extend the surface water irrigation period into May or June; that would give us several cfs additional stream flows in the summer because of that additional storage happening in the spring.”

Thomas HarterMr. Harter said they are also looking at the impacts of beaver dams which raise the water level in the aquifer system throughout the valley; they are also looking at recharging in the gulches on the east side of the valley with irrigation water during the winter to then have that flow support summer base flow on the river. “We’re finding again that we can get additional flows that are on the border of three to 10 cfs, based on these recharge scenarios.”

PROFESSOR RICHARD FRANK, Professor of Environmental Practice and Director of the California Environmental Law & Policy Center

Professor Richard Frank then took the floor to discuss the Scott River Valley case, characterizing it as ‘one of the biggest and currently most heavily publicized pieces of environmental litigation in the state of California.’ He noted that he was also one of the lawyers litigating the case, so he is certainly not a detached observer, and to keep that in mind.

FrankThe ultimate goal of the litigation, initiated in 2010-11, is to establish the principle that groundwater that has a demonstrated hydrological connection to surface waters, like the Scott River, are impressed with and subject to the public trust doctrine, he said. “The public trust doctrine has its origins in Roman Law, and in English Common Law, and relevant to California and the American Southwest, Spanish and Mexican law as well.”

One of the key principles of the last 50 years of environmental law has been the development or embrace of this long-standing legal doctrine as a principle of environmental law,” he said. “What the public trust Doctrine, at its essence provides, is that certain natural resources are incapable of private ownership, but are instead held in trust by the Government for the benefit of current and future generations. A second key principle is that government managers of these public trust resources, known as trustees, have not only the power but have the legal obligation to manage those trust resources with the goal of their long term preservation and protection.”

I would suggest to you that in that sense, the public trust doctrine incorporates principles that we now understand to be sustainable development as well as principles of inter-generational equity – that the current generation shouldn’t consume finite natural resources in a way that diminishes them or makes them unavailable to future generations,” he said.

Traditionally, the public trust was understood by courts to serve three basic purposes: Commerce, navigation and fisheries, the so-called the trilogy of public trust pieces. As a result of some recent, relatively recent court decisions, is that in addition to those traditional public trust purposes, the public Trust doctrine is broad enough to encompass purposes such as recreation, ecological study, open space, and aesthetic concerns, a very important modification, if you will, of the doctrine.

Similarly, the natural resources to which the public trust doctrine applies has expanded over the years, to include the bed and banks of inland navigable lakes and rivers, as well as fish and wildlife resources, he said.  “Another key development of the public trust doctrine in recent years has been to expand even further the natural resources that are impressed with public trust doctrine, and the one most relevant to our discussion today are to expansion of the public trust doctrine to include consumptive water rights,” he said.

California was not the first state whose courts acknowledged the public trust doctrine, but one of the most influential decisions was the National Audubon Society versus Superior Court Case, which is better known as the ‘Mono Lake decision,’ Professor Frank said. He explained that in the very early parts of the 20th century and accelerating through the mid-20th century, the city of Los Angeles obtained water rights to the freshwater tributaries which had historically fed Mono Lake, a large, partially saline lake in the east of the Sierra Nevada range in California and Mono County. As a result of those increasing freshwater diversions to satisfy domestic water uses in Southern California, there was less freshwater flow replenishing Mono Lake and the lake level declined and became more saline. The ability of that lake to sustain brine shrimp, as an important food source for a variety of bird species that inhabit the lake, was threatened.

Mono Lake July 2011 #19So, the National Audubon Society brought suit against the city of Los Angeles and the Department of Water Resources on a number of theories, but the one that got traction and ultimately, was the basis for the 1983 Supreme Court decision was that the water rights obtained legally by the LA Department of Water and Power were subject to the public trust doctrine and that the city’s ability to exercise those water rights and continue to divert all or virtually all of those freshwater resources for domestic purposes to the detriment of the lake violated the public trust doctrine,” he said.

In the 1983 decision, the California Supreme Court agreed with the Audubon society and disagreed with the City of Los Angeles, which had argued unsuccessfully in court that the public trust doctrine has no independent relevance to water rights in California, that they exist to the extent it’s relevant at all that is both subsumed into California’s longstanding statutory system of water rights. “The California Supreme Court expressly rejected that notion and said that the exercise of Los Angeles water rights is subject to the public trust doctrine and that the State Water Resources Control Board as the overseer and regulator of water rights in the State of California, has an affirmative and ongoing obligation to consider public trust values, including the maintenance of the Mono Lake ecosystem as it administers and oversees water rights in California. Not just of the City of Los Angeles, but by extension, by precedent statewide. This was a very controversial decision at the time and it continues to be.”

Mr. Frank then returned to the Scott River Valley case, reminding that the Scott River is an important tributary to the Klamath River Basin and it is important salmon habitat. “Before the expansion of groundwater pumping in the Scott River Valley, the Scott River, which it has been declared navigable by the California Legislature, served a lot of traditional values – recreation and salmon habitat, and while the flow varied dramatically by season, by and large, there was flow in the river; in addition to meeting the existing water demands for surface diversions, recreational and ecosystem values were maintained including a vibrant riparian corridor.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_19The problem is that in the last two or three decades, the number of groundwater wells that have been sunk in the Scott River Valley has increased, and the pumping from those wells has increased in effort to overcome the lack of other surface water supplies,” he said. “And as a result of that groundwater pumping, in certain seasons of the year and in drought periods such as we’re experiencing over the last several years, the Scott River is not only not navigable, but is largely dry for significant portions of the year, and that has the obvious deleterious impact on public recreation, on riparian habitat, and certainly on salmon habitat and migratory patterns.”

As a result of a legislative directive several years ago, the groundwater around the Scott River was adjudicated, meaning that individual rights to specific amounts of groundwater were determined by a court. “The Scott River is one of the only groundwater basins north of the Tehachapi that has been adjudicated, and might be the only one,” he said. “It’s very rare that groundwater basins outside of Southern California are adjudicated. The Scott River Valley is the exception rather than the rule.”

From the standpoint of the parties that I represent in the litigation, a key limitation of the groundwater adjudication was that it was not comprehensive in that it did not encompass the entire or even most of the Scott River Valley, but rather only affected wells, only related to wells and claimed groundwater rights for a few hundred feet from the river,” Mr. Frank said. “So the concern of the plaintiffs was to build on the earlier Mono Lake decision and argue and hopefully establish as a principle of California Environmental and Water Law, that the public trust doctrine, just as it applies to the non-navigable freshwater tributaries of a navigable lake, I.e., Mono Lake, should and does apply equally to groundwater resources when that groundwater has a provable and demonstrated hydrological connection to the surface waters of a navigable river, i.e., the Scott River.”

The case was filed in Sacramento County Superior Court in June of 2010. “The petitioners and my clients are a Bay Area based environmental organization, the Environmental Law Foundation,” said Mr. Frank. “Additionally, the Pacific Coast Federation of Fisherman’s Associations, which is a trade organization of commercial fishing organizations, and along with its research arm, the Institute for Fisheries Resources are the entities which collaborated to bring the lawsuit. On the receiving end of the lawsuit were Siskiyou County and the State Water Resources Control Board.”

The key factual and legal claims contained in that lawsuit filed in 2010 were that the Scott River is a navigable waterway, as demonstrated by its use in its undepleted condition, and also by the legislative declaration that it’s navigable; that there is an established hydrologic connection between the surface flows in the Scott River and the groundwater basin underlying the Scott River Valley; that the Scott River has experienced dramatically reduced flows in recent years as a result of expanding and essentially unregulated groundwater pumping in the valley; And that that unregulated and greatly expanded groundwater pumping has caused a number of adverse impacts on the local environment, including harm to and destruction of migratory salmon and salmon habitat in the Scott River as well as elimination of public recreational opportunities on the Scott River, and while also damage and destruction to riparian habitat, he said.  Most of those facts were not seriously disputed by the county and the Water Board, he noted.

The petitioners argued that the Water Board and the county have both the authority under the public trust doctrine and the affirmative obligation to protect the public trust resources of the Scott River Valley and that both agencies have disclaimed the authority or obligation to do so,” he said, noting that prior to the lawsuit being filed, the Environmental Law Foundation made several attempts administratively to petition the Water Board to acknowledge and take action to address the public trust resource damage caused, but the Water Board at the time said it felt it lacked jurisdiction and authority under then existing California law to do so.

The petitioners argued that in light of the county and the state board’s unwillingness and refusal to protect public trust resources in the river, that the Sacramento County Superior Court, should issue an order requiring that Scott Valley groundwater be managed in a sustainable way consistent with the requirements of the public trust doctrine, and that in the meantime, Siskiyou County should be barred from continuing its ongoing, essentially automatic or ministerial practice of granting any and all new groundwater well building permits that anybody in the county wanted to seek from the county. This is the only form of government approval that until the 2014 legislation had been required.”

Scott Valley 2015-03 - UCD GW Policy Series_Page_16So, after the documents were filed, Siskiyou County sought to have the case transferred from Sacramento County to Siskiyou County where they thought probably correctly it would have a home field advantage in defending the lawsuit in these claims, but the Sacramento County Superior Court rejected the motion, he said. “The county successfully got the court of appeal to review the trial court’s decision refusing to change venue, and ultimately the California Court of Appeal agreed with the trial court that venue was proper in Sacramento County and that the case shouldn’t be transferred,” noting that it managed to delay the proceedings for two years.

More important to the substance of the claim, the State Water Board switched sides in the litigation, even though when requested informally that the Water Board take jurisdiction and acknowledge its public trust responsibility, the board declined to do so,” he said. “Sometimes litigation can be an effective nudge, or in this case maybe a cattle prod, I don’t know. But the water board ultimately concluded, and in legal findings said, “We agree with the petitioners that inter-connected groundwater that has a demonstrable hydrologic connection to surface water in the amount of water that does come within our jurisdiction, and that we, like the petitioners, read the Mono Lake decision as requiring public trust jurisdiction over groundwater pumping on these facts.”

Most importantly, last July the Sacramento County Superior Court issued a decision agreeing with the petitioners that the public trust doctrine does in fact apply to hydrologically connected groundwater, and that the public trust doctrine therefore applies to Scott River groundwater, and that the public trust protects fishing, boating, fish habitat, and ecosystem study. Since the State Board had already acknowledged in the litigation that it had public trust responsibilities and was prepared to carry them out, the judge focused on the county and said that yes, the County does have affirmative obligations to consider the public trust doctrine.”

The County immediately sought a review all the way to the Supreme Court, and we as the petitioners agreed it was a sufficiently important issue in the matter of law and public policy that the Supreme Court should take it up, he said. “So in an unusual temporary alliance, we agreed and supported the Supreme Court taking review. … Two weeks ago, Supreme Court denied review, at least at this point. So the case remains back in the trial court.”

Professor Frank said an interesting point now is that the County has just filed notice that they are going to claim in new filings that the recent passage of the 2014 groundwater legislation occupies the field and displaces any role that the public trust doctrine might otherwise have, and that therefore, California water rights system is now amended by virtue of the new groundwater legislation. “I’m editorializing here, but I think that that’s a weak argument inasmuch as there are several references in the legislation to the fact that the groundwater statute does not, and is not intended to amend or change California’s substantive water rights law, but we’ll see.”

The floor was then opened up for questions.

Question: One thing about this that seems problematic is the remedy you sought is tied in with what you called “well-drilling permits”. But my understanding of those permits issued by the county is they’re about the integrity of well construction. They’re not about the extraction of water. So wouldn’t they be changed to something entirely different? The remedy was to say they’ve got to do an examination of extraction, and the impact of the extraction on the surface water before they issued the permit.

In terms of a long term permanent remedy, you’re absolutely right,” replied Professor Frank. “When we were talking about halting the issuance of the groundwater permits as so-called interim relief while the court decides this matter and formulates and declares exactly what the county and the State Board’s long term obligations are, to integrate public trust concerns and management with the State’s, at least new groundwater regulatory role, that at least stop making the problem worse by granting new groundwater permits without even giving a passing glance to the public trust doctrine or the principles that underline it.”

Question: It seems like the California Constitution says that the State shall consider the public trust. So, if we’re saying you prevail on that issue, it doesn’t necessarily mean they have to protect it.

That’s a very good point, but I would take polite issue with you said that the California Constitution talks about the public trust doctrine being considered,” said Professor Frank. “I would argue that some aspects of the public trust doctrine are found in our State Constitution, but unlike some states, including Hawaii, that explicitly do talk about the public trust doctrine and its connection to water resources, California’s Constitution does not. But your larger point is absolutely correct, that the whole holding of the Mono Lake decision is that the public trust doctrine is this independent principle that water managers, including the State Water Resource Control Board, must consider in administering the California Water Rights System, including the issuance of new permits or the modification of existing water permits. The Mono Lake decision does not indicate, or much less guarantee, that the public trust doctrine always wins. It’s just that it’s a separate legal doctrine that water managers have an affirmative obligation to acknowledge and consider in making their case-by-case, basin-by-basin water decisions.”

For more information …

To watch the lecture, click here.

For more from the California Water Policy Seminar Series …

This is the third year that Maven’s Notebook is covering the lecture series at UC Davis.  Previous speakers have included John Laird, Mark Cowin, Felicia Marcus, Tim Quinn, Jay Ziegler, Ellen Hanak, Michael Lauffer, Ronald Robie, Harrison ‘Hap’ Dunning, Michael Rosenzweig and many more.  You can access all coverage from all years in the archive here:  California Water Policy Seminar Series Archive

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