GROUNDWATER RIGHTS PRIMER: What Agencies & Project Developers Need to Know

A seminar at McGeorge School of Law takes a deep dive into groundwater rights and SGMA

California depends on groundwater for a major portion of its annual water supply, and sustainable groundwater management is essential to a reliable and resilient water system. In recognition of this, the legislature passed a three-bill package known as the Sustainable Groundwater Management Act in 2014 that set in motion a plan to sustainably manage the state’s groundwater basins.  The centerpiece of the legislation is recognition that groundwater management is best accomplished at the local level, and so SGMA requires the creation of groundwater sustainability agencies to develop and implement locally-developed groundwater sustainability plans, allowing 20 years to achieve sustainability.

The legislation explicitly states that it does not alter any water rights: the legislation adds Water Code section 10720.5(b) that states that nothing in the legislation “determines or alters surface water rights or groundwater rights under common law or any provision of law that determines or grants surface water rights.”  However, Groundwater Sustainability Agencies and project proponents must address such rights in groundwater sustainability plan development, projects to increase yield such as recharge projects, and reducing pumping to reach sustainability.

California’s structure of groundwater rights is notoriously complex, directly related to hydrologic conditions, and complicates the goal of sustainable groundwater management.  At the McGeorge School of Law’s Executive Training on Water Rights in Groundwater: A Deep Dive into California Groundwater Rights, Professor Jennifer Harder and Hydrogeologist Derrik Williams discussed the convoluted world of groundwater rights as it exists in California.

The law of groundwater is in fact an amalgam of mythology and pragmatism,” began Jennifer Harder.  “It is the intersection of these two things, so talking about legal principles of groundwater law is different than talking about principles in the context of criminal law or tort law.  It’s very bound up with the history and the science.

In the early years of groundwater law, the courts found groundwater to be ‘secret’, ‘concealed’, and so mysterious that legal rules could not be identified for the resource, Ms. Harder said, presenting a slide with a quote from one of the earliest cases in groundwater law.  “The court was so flummoxed by the idea of trying to develop legal rules for such a secret resource that early on, the court adopted a rule called absolute ownership,” she said.  “That concept meant at the time that everybody who owned land owned all the groundwater beneath the land and they could pretty much do whatever they wanted with it.  Since that time, our groundwater system and legal system has been trying to get away from that really terrible starting place and to figure out rules that help us actually manage our groundwater basins in a way that makes sense for everyone.

Derrik Williams noted that working in groundwater generally involves a compromise between legal principles and scientific principles which don’t line up very well in many instances.  “What happens in most of the groundwater law issues is that it’s not a fight between the attorneys and the hydrologists, but there are a lot of discussions of what makes sense and how do we comply with that law in a way that makes scientific sense,” he said.  “We’ve come up with some very good compromises, sometimes each of us thinks that wasn’t such a good compromise.  My rule today is going to be when I can, give you some insight on how hydrologists view this, and some of it will be to tell Jennifer yes, that the way the law views it and it makes no sense to me.”


Mr. Williams said that from a groundwater hydrologist’s viewpoint, groundwater is effectively all the water that it is underneath the ground that fills up those pore spaces between the sands and the clays, fills up the fissures and cracks in the rocks – all of that counts as groundwater to a groundwater hydrologist.

In the picture on the left, the blue area is referred to as a saturated aquifer; this is the area between the grains of sand and it’s full of water.  If you put in a well, that’s where you’re pumping from basically, and that is what everybody thinks of as groundwater, he said.  But he pointed out that in the area above the saturated zone, there’s a little bit of water in between the soil particles that also counts as groundwater to a groundwater hydrologist – it’s just groundwater you really don’t have access to.

Beneath the aquifer, there is a rock that has cracks in the rock; water in those cracks also counts as groundwater; if you go to the beach and you dig a hole and water pours in, even though you are right next to the ocean, to a groundwater hydrologist, that’s groundwater too, he said.  Likewise for geysers.

That’s what we’re talking about from a groundwater hydrologist’s viewpoint,” said Mr. Williams.  “All of that counts as groundwater.”


Ms. Harder noted that water resources are often divided into two categories:  Surface water (such as rivers, streams, and lakes) and groundwater; in California law, the state has two entirely separate legal rules for each of these physical systems.

Some of the rules are analogous to each other, but for the most part, they are treated like separate systems,” she said.  “There is buried in California law, some recognition of the fact that surface water and groundwater are in fact connected physically, but there’s a prevailing mythology that the law doesn’t recognize that connection and for the most part, the way in which we manage the water today does not recognize that connection.”

Everybody knows they are connected and it is causing some problems,” said Mr. Williams.  “The future of water management is going to be trying to figure out how to connect those two … the physical part of how they are connected is much easier than the legal part of how they are connected.”

In a groundwater aquifer, the level below which the ground is saturated with water is the water table.  Mr. Williams explained that if the water table is below the level of the stream, water will pour out of the stream into the aquifer because water at a higher elevation wants to go to a lower elevation; this is referred to as a losing stream.  As a losing stream flows along, there will be less and less water in the stream, even so much as to completely dry out.

It’s not drying out because anybody in the stream is taking water out of it; it’s just pouring into the aquifer,” he said.  “If you have some water right on that stream and you say, where did my water go? It just went into the aquifer there.  It’s because the gravels in the aquifer go right up to the edge of the stream and there’s nothing preventing that water from going in.”

It’s the opposite case where the groundwater is higher than the stream, he said.  The water will pour into the stream so as the stream flows along, it will have more and more water – not because anybody did anything, it just pours in there from the groundwater.

So the groundwater aquifer and the stream are easily connected; there’s nothing that prevents the water from flowing back and forth between them.  “Everybody believes it’s one water; it’s just we have two legal systems that deal with the water if it happens to be in the ground as opposed to if the water happens to be in the stream,” Mr. Williams said.  “It’s just an inch on this picture, but a hugely different legal system.”


Ms. Harder then turned to the concept of subterranean streams and percolated groundwater.

Percolated groundwater is generally groundwater flows through the earth much like a sponge, which is generally what we think of as groundwater; it’s the water that fills the pore spaces between sediments or fissures and cracks in rocks.    The ‘subterranean stream’ is defined as ‘subterranean streams flowing through known and definite channels.’  It comes from old case law back in the late 19th and early 20th century when the courts decided that there was a difference between percolating groundwater and subterranean streams, and they fashioned different legal rules for them.

When California adopted its water code, it integrated that distinction into the water code and it gave a certain kind of legal status to percolating groundwater and a different legal status to subterranean streams,” she said.  “We actually have fashioned a legal test for telling the difference between the two that is supposedly based on hydrology.  Theoretically.”

This is one of the subjects that drives groundwater hydrologists crazy and I think it drives attorneys crazy also, because there is this test out there on being able to differentiate between what is percolated water and what is a subterranean stream, and from a groundwater hydrologist’s viewpoint, everything is percolating water,” said Mr. Williams.

The key point of the definition on subterranean streams is to be able to identify a relatively impermeable bed and boundaries for the stream; basically you have to be able to map an underground stream course where the stream within the underground stream course is highly permeable, he said.  He explained that permeable means it transmits water easily, such as gravel or sand; by contrast, modeling clay is impermeable.

What they are asking us effectively to do is to map a course where within that course, there is relatively permeable sediments and outside of that course, it’s relatively impermeable,” Mr. Williams said.  “The concept of relatively is what drives us all nuts there.  Because there is no definition of what’s the difference between permeable and impermeable.  And it is location dependent, by the way.”

There is no legal or technical dividing line between permeable and impermeable.  “Permeability covers 13 orders of magnitude in its measure,” Mr. Williams said.   “It is the process on the planet that has the largest range of any process on the planet.  There are more numbers on permeability than anything else.  So if you’re covering 13 orders of magnitude of permeability, and you’re somewhere in the middle, what the court is asking is, how far away do you have to go before you say it’s relatively impermeable.  Do you go an order of magnitude 1, 2, 3, 4 orders of magnitude away?  There’s no real good guidance for that.”

In geology, things rarely have straight lines; you rarely find gravel right up against clay, he said.  “What you’re going to find is some sand and a little clay, and a little more clay, and after a couple miles, you get clay, and the question is can you identify the line where you go from permeable to relatively impermeable, and that becomes very, very difficult for all those reasons.  That is why this definition drives both hydrogeologists and attorneys nuts.  It’s a very vague definition that is because of the realities of geology, and it’s almost impossible to implement in any consistent manner.”

Ms. Harder said that in terms of managing groundwater, there’s no real need for these two systems, yet this distinction still exists in California’s legal system.  “All groundwater is technically presumed to be percolating groundwater, unless and until it is determined to be a subterranean stream,” she said.  “Once it is determined to be a subterranean stream, then there may be, particularly if pumping started after a particular date, December 19, 1914, then the State Water Resources Control Board has permitting authority over that pumping.  If you don’t have a subterranean stream, or if you can claim a certain type of right to a subterranean stream, the SWRCB does not have permitting authority over that pumping.”

The distinction triggers the need to interact with the State Water Board and obtain a permit or not.  “There have been some entities that have been pumping and thought they were pumping percolating groundwater, and got caught out and told that they were actually engaging in unauthorized diversions because they were really pumping from a subterranean stream, so legally it can make a big difference,” said Ms. Harder.  “For good management, it doesn’t make that big of a difference, and I think we could probably easily consider them one system.”

The courts have recognized this, although it took until 2006 to actually get some certainty from the courts on this question, Ms. Harder said.  “The court said, in fact, when you start talking about the distinction between percolating groundwater and subterranean streams, that ‘it’s a little bit like Alice in Wonderland.  That you’ve suddenly descended into Wonderland, because the legal categories are drawn from antiquated case law and bear little or no relationship to hydrologic reality.’  But nonetheless the court upheld the system, because it is essentially said it wasn’t the court’s place to rewrite those rules and that if the rules needed to be rewritten, the legislature should do that.  And so we have this distinction in the law today.”

Ms. Harder said that it was important to know that subterranean streams exist, but the remainder of the presentation would be focusing on the much bigger category of percolating groundwater.


Mr. Williams then gave a simplified version of how basins work, focusing on the concept of the water budget.  A water budget is one of the first steps in managing a basin; that’s how we decide how much water is in the basin and how we are going to manage it, he said.

He presented a graphic of a water budget, explaining that the blue arrows represent water that is coming into the basin, such as precipitation, percolation from stream beds, or managed aquifer recharge; the green arrows represent water taken out of the basin, such as vegetation, irrigation of crops, and pumping for municipal use.

So you have water coming in and water going out, and if they don’t balance – if the water that’s goes in is not exactly the same as the water that comes out – then you’re going to get what hydrologists call a change in storage,” Mr. Williams said.  “A negative change in storage – that is you’re losing water out of the basin, and water levels in your well are going down.  A positive change in storage means we’re putting in more water then we are taking out, and the water levels in your well are going up.

The basic concept of the water budget is to figure out all the inflows and sum them all up; figure out all the outflows and sum them all up, and then project what will happen to the aquifer if these continue into the future.  “The interesting thing about this is that when you look at all the inflows and the outflows, we have control over very few of them,” he said.  “We might have a little control over what’s called Managed Aquifer Recharge on the inflows where you recharge water, but if you’re going to recharge water, you kind of need a source of water to recharge, and often that’s hard to find.”

The one thing you can really control is the pumping from the aquifer, which is why when aquifers are managed, usually it’s done by managing how much everybody pumps, Mr. Williams said.  “That is the one big hammer we have that gets us to the point of managing the aquifer,” he said.  “So when we talk about managing a basin, we want to manage the basin so that our water levels over time are fairly consistent, and really the only the tool that we have to do that is the well pumping, and that’s what we focus on and that’s why water rights for well pumping are so important.


Mr. Williams then discussed how a hydrologist views overdraft, noting that it is different than how the legal systems views overdraft.  He reminded that you don’t want to be taking out more water than is being put in, otherwise you will begin to overdraft the basin.

There are some important factors, such as for it to be overdraft, it has to happen consistently and over a long period of time.  “If after one year, you took out more water than you put in, that’s not overdraft,” he said.  “It just could have been a dry year.  You want to look at many years where you have wet years and dry years, so you want to see if over many years on average, are the water levels continuing to go down? Are we taking out more water out of the basin then we’re putting in?  If over the long period, you’re taking out more, you are in overdraft.

Mr. Williams presented a graphic by the USGS that shows the groundwater overdraft in the Central Valley, noting that the purple line represents groundwater levels in the Tulare Basin in the southern San Joaquin Valley, which has been losing storage since 1962.  “This is the classic picture of overdraft,” he said.  “They are just losing the amount of storage that they have.  It’s up to somewhere between 1.5 and 2 MAF per year.  That’s enough to serve water to somewhere 3 million and 4 million homes for a year, and we’re losing that in storage.

Mr. Williams also noted that when we talk about groundwater overdraft, we generally think about it in terms of constantly declining groundwater levels, but this isn’t always the case.  “If you are in somewhere like the Salinas Valley which is right next to the ocean, and if you pump water in the Salinas Valley, what happens is the ocean comes in and replaces the water you pumped out; it’s very salty and it makes your wells useless.  Your water levels aren’t dropping because the ocean came in and said I’m here to fix your water levels, but you have run out of usable water.  So from a hydrologists viewpoint, overdraft isn’t just lowering groundwater levels, it’s running out of usable water in your aquifer.”


Ms. Harder then gave the legal definition of overdraft, which is the average annual amount of water extracted for long-term period, generally 10 years of more, that exceeds long-term average annual supply of water to the basin, plus any temporary surplus.  The legal definition stems from case law that’s been building for decades; it was more recently incorporated into the Sustainable Groundwater Management Act with a few refinements.

Temporary surplus is defined as the amount of water that may be pumped from an aquifer to make room to store future water that would otherwise be wasted and unavailable for use.  Ms. Harder explained that the idea of the temporary surplus is that in any given aquifer, there may be a situation where the water levels are declining over the long term, but there may be a short-term period where a lot of water comes in and raises those water levels; the temporary surplus included in the definition allows the opportunity to take the water that’s raised the water levels out because more water is expected to be coming in.

The idea is that if you take out that surplus, that amount that is added to the lower levels and use it, you free up space for new water to come in, whereas if you didn’t take it out, the basin isn’t full and the water would just runoff and be wasted to the basin, so that’s the idea of temporary surplus,” Ms. Harder said.  “We try to maximize the opportunities for pumping to make the pie bigger, essentially.”

That is a fundamental principle in California water law – that we attempt to squeeze every drop of value out of every drop of water,” she continued.  “We call it the maximum use or fullest extent principle.  We try to use water to the fullest extent of the law.  It’s part of our state constitution; before it was part of our state constitution, this idea that we are going to squeeze maximum value was actually part of our ancient case law and it’s part of the case law of most of the states in the western United States.  What this temporary surplus concept recognizes is that even though you may be in a declining situation, there may be opportunities to pump.  And this becomes very important for water rights purposes.”

As a legal matter, just because you are in overdraft, that doesn’t necessarily mean that you can’t continue to pump, Ms. Harder said.  “There are some circumstances in which basins are managed for what we call managed depletion or managed overdraft, meaning that we know we’re continuing to pump in overdraft, but we have a plan to bring the basin back.  This is part of the definition of overdraft in SGMA itself, which explains that you can manage the extractions and recharge the inflows and outflows to ensure that declining levels or declining storage during drought is offset during other periods.”


Another concept is safe yield, referred to in SGMA as sustainable yield.  Long before SGMA, the concept of safe yield was embedded in state law since the process of adjudicating groundwater basins began.  The idea of safe yield is to identify the amount of water that can be extracted on an annual basis without causing undesirable results; the key to establishing safe yield is to identify what the undesirable results are, Ms. Harder said.

Mr. Williams noted that safe yield or sustainable yield is a hydrogeologic concept, but it is a term that many hydrogeologists really don’t like very much.  “It works well as long as you’re talking in large generalities,” he said.  “It doesn’t work very well if you get down to the specifics, but this is one of the great convenient compromises that we’ve come to where it works well enough for a hydrogeologist that we can use it and it works well enough for the legal group that we can use it there.  This is one of the issues that we’ve really compromised on.”


There are six undesirable results that are defined in SGMA; historically, in water law, many of these have been identified as an indicator of overdraft.  “It’s not clear that we have actually managed our basins to take care of these undesirable results,” said Mr. Williams.  “So far we have used it to say, ‘this is a bad thing and we’re going to manage our basin,’ but we don’t necessarily manage our basins to take care of these.  In SGMA, you’re supposed to take care of these.

The six undesirable results are:

  • Groundwater levels dropping: If groundwater levels have been dropping over years and continue to drop, that is considered undesirable. This can cause shallow waters and the shallowest wells in the basin to go dry, he said.
  • Reduction of groundwater storage: Long-term declines in groundwater levels, if predominant within a basin and not offset by rising groundwater levels, cause long-term reductions in groundwater storage.
  • Seawater intrusion: Seawater intrusion is the movement of seawater into fresh water aquifers; it is caused by decreases in groundwater levels or by rises in seawater levels.
  • Degraded water quality: Overpumping of depleted aquifers can cause contaminant plumes to move around, or cause poor quality water to leak in from superposed and underlying aquifers.
  • Subsidence: Subsidence is the concept that if you pump water from a very deep aquifers, the land surface actually collapses; it starts to drop.  “In the San Joaquin Valley, it’s dropped more than 30 feet.  It has dropped a long, long way.  Your land is literally falling out from under you there.
  • Depletions of interconnected surface waters:We want to managing our aquifers so we aren’t taking all the water out of the streams,” said Mr. Williams.  “The question that comes up is, what is undesirable?  How much water could you take out of a stream from pumping your aquifer and still be in a desirable condition as opposed to an undesirable condition? That’s where the rub really is, is to define what that line is.

Ms. Harder then pointed out that buried in these concepts, particularly in SGMA, is the concept of significant and unreasonable.  “So it’s not just any trigger of any one of these results that triggers the need to manage the groundwater; it’s some conclusion that it is both significant and unreasonable, and that it is a legal analysis,” she said.  “That it is a fact-specific judgement call, and that’s something we’re going to be grappling with going forward.”


Under SGMA, the Department of Water Resources has determined the high and medium groundwater basins that are subject to SGMA, as well as designating some basins as being critically overdrafted.   With SGMA, you identify what is the sustainable or safe yield in those basins that will avoid those undesirable results, and then you have a framework for achieving that sustainable yield, Ms. Harder said.

Groundwater Sustainability Agencies or GSAs are supposed to develop groundwater sustainability plans that will identify the significant and unreasonable undesirable results, the sustainable yield and what needs to be done to manage to get away from overdraft and towards safe yield,” she said.

SGMA incorporates the existing framework for water rights in California; the legislation specifically says that nothing in SGMA determines or alters surface water rights or groundwater rights under the common law.  Ms. Harder said it is critical to understand how surface water rights and particularly groundwater rights work, because in any solution that is devised to comply with SGMA and to achieve sustainable yield must keep those groundwater rights in mind or the solution is subject to challenge and being overturned.


There is a distinction between in the law between groundwater that occurs naturally in a basin without human interference and groundwater that is added to the supply by human action, and different legal rules apply to each.  Ms. Harder noted that there are other names for augmented supply that are sometimes used, such as replenishment water or supplemental water.

The first thing to know about rights to native groundwater is that a permit is not needed from the state of California to pump native percolating groundwater; those rights exist as a matter of common law, said Ms. Harder.  “In California, it’s been said that groundwater has remained unregulated for so many years.  It’s not exactly true that it’s been entirely unregulated; there are some basins that have fairly sophisticated groundwater management projects, but at the state level, there are only a couple of instances in which the State Water Board has gotten involved with percolating groundwater pre-SGMA.  Pre-SGMA, no water right needed from the state.”

With respect to rights to native groundwater, there are several types of water rights.  Ms. Harder said that the first type of groundwater rights exist when the aquifer is not overdrafted; next there is the concept of what happens to those water rights when the aquifer does go into overdraft; and then that overdraft triggers a third kind of groundwater right that comes into existence when the basin goes into overdraft.

Before the basin is in overdraft, there are two kinds of rights to native groundwater:

Overlying right: There is a right to groundwater that inheres in ownership of land, similar to the idea that riparian rights wherein you own a parcel of land that is adjacent or contiguous to a river, creek, stream, or lake.  In the groundwater context, a land based right to groundwater exists where your property physically sits on top of the groundwater basin.

We say that the contiguity exists because your property is essentially touching that groundwater basin, and for that reason, the rules that apply to riparian rights are analogous to the rights in percolating groundwater land-based rights, what we call overlying rights,” said Ms. Harder.  “The two rights share a lot of common qualities.  It is sometimes said that overlying rights are riparian rights turned on their side.  The analogy is not complete, but for the most part, similar rules apply.  This is regardless of depth.  The overlying right exists where you own land overlying a groundwater basin.”

Appropriative rights: Appropriative rights exist where you don’t own the overlying land or you are a certain kind of pumper.  “This kind of right is based in use,” she said.  “The whole concept of appropriation is to capture something unto yourself and to use it, so that’s where the term appropriative rights come from.  If you are a groundwater pumper and you don’t own overlying land or you own overlying land and you are taking the water you are pumping outside of the groundwater basin, you are an appropriator.

It’s important to realize that appropriators are no longer maintaining that connection between their pumping and that overlying property.  “That connection is critical,” said Ms. Harder.  “It’s almost a spiritual connection.  They say that the land, the soil, is entitled to its waters and that there’s this deep connection between the two.  Once you sever that connection, you are no longer entitled to the privileges of land ownership.  Landowners who hold these rights are in what we call the first class; they get water first.  Those who break that connection get water second.”

Public water agencies are also considered appropriators.  “Whenever you have a public water supplier that’s pumping groundwater and the public water supplier jurisdiction is located on overlying land, all of their pumping is, as a matter of law, appropriative,” she said.  “It is converted as a matter of law from overlying to appropriative.  This is true because when a public water supplier is serving the water supply to individual residents and businesses in their jurisdiction, that public water supplier is not acting as a landowner.  It is not maintaining that almost spiritual connection to the land.  It is serving other landowners.  And so we break that connection.”

When you have an overlying right, you do not have the right to the pump the water that you somehow say, these are the molecules under my land and I have the right to pump those molecules,” Mr. Williams said.  “Your overlying right is to pump from the groundwater basin … We’re not talking about water that has to be physically under your land at a certain point in time.  It’s just a right to pump from the basin.”

Ms. Harder noted that there are always exceptions, and there is an exception here.  “The exception is if the municipal pumper, the public supplier, is providing water to publicly owned property.  For example, if a city owns a city park and it’s providing water to that city park, that actually can claim overlying status, but that’s relatively small.  For the most part, public water suppliers are considered appropriators.  That one fact, that one legal rule, is actually what has completely messed up our groundwater law ever since.  That’s what has caused all of our problems and I’ll explain why.”

Ms. Harder also noted that there is some question among lawyers about if you’re pumping groundwater on your overlying property, and if that water is used not on your parcel but moved to another parcel in the basin, if you’re still exercising overlying rights; this issue hasn’t entirely been clarified in the law.

When you get into an adjudication situation, these things have worked themselves out pragmatically,” she said.  “That’s why I say the law of groundwater is the law of pragmatism for the most part, but there is a lack of clarity.”

Private water companies are considered municipal water suppliers if they are providing water for public usage, however there is an exception.  A mutual water company can be organized in such a way that it holds the water rights on behalf of the individual landowners, and if it’s properly organized so it is just exercising those rights on behalf of the landowners and they are getting the shares back in return, that can maintain the overlying right, Ms. Harder said, noting that’s the only exception; otherwise they are considered a public water supplier.

Ms. Harder noted that in most groundwater disputes, the overlying users most often tend to be the irrigators and the appropriators are cities in the basin or anybody exporting water out of the basin.


It’s the ownership of land that makes overlying rights special, said Ms. Harder.  “This is how we think about it in water law,” she said.  “The rights are grounded in that land ownership so they are not based on the concept of beneficial use.  All other water rights in California are subject to the idea that if you don’t use them, you lose them.  There is this connection to the need for putting things to beneficial use.  This is not true for overlying rights.  Rights that are grounded in land ownership are not lost for non use.  They exist in perpetuity unless something very specific happens.  The landowner can for example convey away their rights purposefully.  But for the most part, the fact of use or non-use does not technically deprive you of the rights.”

She noted that if the basin is not in overdraft, and if you’re not actually pumping your overlying right, there may be practical consequences, but as a legal matter, your right is a valid property right whether you are pumping or not.

Ms. Harder also noted that for overlying rights, there is no fixed quantity.  “You don’t have a right to a specific amount of water; you have a right to a correlative share of the basin,” she said.  “Correlative means they are on the same playing field with respect to their legal rights; we say their legal rights are equal.  That doesn’t mean they are entitled to an equal amount of water, but we say, legally those rights are equal to each other, and as a result, you can start, stop, and increase the amount of water you can pump and still be in compliance with the law; it can go up and down over time if you are an overlying owner.”

Ms. Harder noted that as in all water rights in California, the limitation of reasonable use applies to overlying groundwater rights as well.  “That limitation has existed in our case law since the very beginning; it was later incorporated into our constitution, Article 10, Section 2 says that all water must be used reasonably, and this limitation applies to overlying owners as much as it applies to anybody else.”

Overlying landowners have first class rights, which means that the whole group of overlying owners gets their needs met before any appropriators get any water, Ms. Harder said.  “If there’s no water left over for appropriators, appropriators don’t get any water.  That’s how that works.”

Overlying rights are correlative, which means a legally equal right, but it doesn’t necessarily mean equal amounts of water, she pointed out.  “If you have two, you don’t necessarily divide it 50/50.  Instead, the division is based on some equitable assessment of what’s fair, what’s just, and what makes sense under all of the circumstances.  The types of factors that might be considered include things like the amount of acreage that’s owned, as somebody who owns a lot of land will probably get more water than somebody who has relatively little land.  You might also look at the type of crop that’s being planted and other elements of the water need.”

So if a groundwater basin has 100 units of water, the overlying owners won’t necessarily divide that 50/50; the larger acreage might get 70% of the available supply and the smaller acreage would get 30; that would be a correlative or equitable allocation, she said.

Because groundwater rights and surface water rights are two legally separate systems, you don’t have to consider surface water in most cases, said Ms. Harder, but she noted that there is some precedence in case law for considering groundwater and surface water a common supply.  There have been groundwater basins that have been adjudicated and developed a practical solution where they do take into account both the surface water and the groundwater, so as a practical matter, that has happened.

Ms. Harder also acknowledged that SGMA introduces the idea that one of the six undesirable results is the significant and unreasonable depletion of surface water supply, as well as habitat that depends on that surface water supply, which starts to get at the connection in a new way.

This is one of the great challenges of SGMA and one that we’re going to be talking about a lot going forward,” she said.


Ms. Harder then turned to the relationship of appropriative rights to overlying rights, reminding that appropriative rights are based on beneficial use.  “One of the key principles is that you have to continue to use them or you lose them,” she said.  “The quantities established by pumping, and appropriators are entitled to a specific quantity of water, based on the amount that they have been historically been pumping.”

However, a key distinction is that appropriators are technically only allowed to pump if there is surplus in the basin.  “Once the basin goes into overdraft and there is no surplus, any pumping by appropriators is wrongful, and it changes the water right,” she said.  “Appropriators are grounded in surplus; overlyers get their water first.  Then if there’s any left over, before overdraft, that’s the water that can be appropriated.  So it’s considered a surplus right.  They are second class, so overlyers get all their water in the class first, before appropriators get any.”

Another important distinction is that while overlyers have a correlative allocation in times of shortage, for appropriators, the shortage principle is priority: first in time, first in right.  “Appropriative rights are sometimes referred to as the doctrine of prior appropriations, because who got there first matters so much,” said Ms. Harder.  “So an earlier pumper gets all of their demand met before a later pumper gets any water, and the priority is based on the date of first pumping.”

So in the example, the groundwater basin has 200 units; the overlying rights holders are allocated 100 units.  Appropriator 1 started pumping in 1910, and appropriator 2 started pumping in 1950; appropriator 1 is considered the senior, and if they have a demand of 90 units, they get all of the 90 units demand filled before Appropriator 2, can take any water at all.  “So as between appropriators, it’s a priority system,” Ms. Harder said.

So in summary, overlying rights are a class senior to those appropriators, so there are senior overlyers and junior appropriators.  “So if you have a groundwater basin with 100 units, and you have the overlying demand that totals 100 units, the overlyers would get it all and the appropriators get none,” she said  “But if the amount of water in the basin increases, and remember the amount of water in the basin goes up and down, depending on water availability, recharge, inflow, outflow, and all that stuff, then the overlyers get their demands satisfied and the appropriators can then take water in priority order.    So appropriator one would take their demand and appropriator two would take their demand.”


Safe yield (or sustainable yield) is the amount of water that can be pumped from a basin without causing undesirable results.  “If you are exceeding the safe yield and if you have those undesirable results, you are in overdraft, and if you have overdraft, it changes the water rights,” said Ms. Harder.  “If you have appropriators who continue to pump their water during conditions of overdraft, their rights transform from those appropriative rights to what we call prescriptive rights.”

Prescriptive rights or prescription is grounded in the legal concept of adverse possession; it’s a concept that seeks to reward those who put property to valuable use and to penalize people who sit on valuable resources and who don’t use them, she said.  “Society has this value embedded in the law that we prefer active exercise of your property rights, and not potentially fallowing or sitting on those property rights.  So the idea of prescription is that if you are invading someone else’s right, you are taking water when you’re not supposed to be in the water context, you are gaining a right to adverse possession.”

There are several criteria that need to be met in order to acquire a prescriptive right, including that the pumping was wrongful, it was occurring during overdraft, and was continuous for a five year period; there also has to be some sort of notice or awareness that the basin is in overdraft.  Ms. Harder noted that different courts have found different sets of facts to equate to notice.

“Once you have established that there is or was overdraft, that you have this appropriative pumping during this five year period and there was notice, then the appropriative rights then transform into this prescriptive right as a matter of law,” she said.


Ms. Harder reminded that overlyers right to the groundwater is not grounded in use; it’s grounded in land ownership, so they don’t have any obligation to continue pumping in order to maintain their right.  If they are not pumping, then it’s called a dormant or sleeping right, or sometimes an unexercised right; it might also be called a future right where they intend to pump in the future.  A prescriptive right is gained by an active appropriator against the dormant overlying right.

So if you a senior overlyer who is not exercising their right, and you have an appropriator who is pumping during a condition of overdraft, that appropriator may be gaining a prescriptive right,” Ms. Harder said.  “As a practical matter, the likelihood is that right is probably affecting those sleeping overlying rights the most.”

Technically, you could say that the appropriator is prescripting against all senior rights and that all higher priority rights are at risk of adverse possession, but the courts have held that if the overlyer is continuing to pump actively, then they are not sitting on their rights, they are not sleeping on their rights, and their rights can be protected through this context we call ‘self-help,’” she said.  “This is the phrase the courts have come up with.  The overlyers, by continuing to pump, protect their rights through self-help.  You might almost think of it as a defense against prescription in a sense.  So as a practical matter, what you end up with is the prescriptors tend to encroach on those dormant overlyers.  When we get into allocation, you’ll see that there are a lot of questions about how this works as a practical matter.”

One key rule to understand about prescription is that there is no prescription against public agencies, Ms. Harder said.  Most of the appropriators in basins are probably public agencies like cities or municipalities, and as a matter of California law, you can not adversely possess the property of a public agency; they don’t have the same obligations to continually exercise property rights in order to maintain them.

Ms. Harder then gave an example where the groundwater basin has 100 units.  If the basin is in overdraft, the overlyer active pumper may be pumping 50 units; the appropriator then converts to a prescriptive right, and may also be able to pump.  There is a question mark about the dormant overlyer; there is the tendency is to think that the dormant overlyer automatically loses their rights but that’s not true, she said.  “As a matter of law, the senior status of the dormant overlyer remains senior.  They do not automatically lose all rights to pump.  Diminishment of that right may come later in the allocation process.  So I’m flagging the dormant overlyer as the most vulnerable in this situation.”

As the courts developed this concept of prescriptive rights, they were focused on not so much being entirely consistent with the law of adverse possession or with the best set of rules that would be clear in the future; they were concerned with the very pragmatic consideration of protecting active pumpers and the public water suppliers.

Remember, those public water suppliers are always appropriative and that means they are always junior in the pre-overdraft scheme, and so theoretically, if you get into overdraft and if you apply strict priority, all of the cities would be out of luck; they just would not have any water,” she said.  “So the development of the prescriptive rights doctrine was an attempt to avoid that situation and to make sure that the cities weren’t out of luck.  That is how it evolved.”

So what about the conundrum of the dormant overlying right?  Legally, that right is still senior, even if they are not using the right and even if they never use the right, it is still senior; however, the appropriator who is engaging in prescription because the basin in overdraft, has to be prescripting against somebody, and so the question is, what do we about that?  Ms. Harder said there is another concept, that of the physical solution, which comes from the idea embedded in California’s constitution, Article 10, Section 2 which says that water has to be used to the fullest extent possible, and that all water uses are limited to reasonable use.

You take those two concepts together and the California courts have developed the idea that there is the ability for courts in the beginning, and now perhaps other regulators as well, to look at a set of water right priorities, and to figure out how to make sure that we reach a water allocation that works, while mostly respecting those priorities, but perhaps rearranging them a little bit and making some changes,” said Ms. Harder.

However, that’s not a wholesale permission to completely rearrange the water rights or to ignore them, Ms. Harder said.  The California Supreme Court made that clear in the Mojave case in the year 2000; the situation between dormant overlyers and prescriptors and other rights elements in that case had caused the court to say that it was a giant mess, and the court used a concept called equitable apportionment which was an allocation that worked to be the most equitable to everybody.  That solution was appealed to the California Supreme Court which said they appreciated what the lower court had tried to do, but they cannot completely ignore property rights in water; they have to have some protection.  The court said that a senior user can be required to perhaps pay some amount of money to participate in a solution, or to incur some other kind of diminution in their right, but that right cannot  be totally extinguished; there has to be some consideration.  The property right still matters at some level.

So under the physical solution doctrine, you have the ability to be equitable and pragmatic, but the rule of law is to protect priorities unless they lead to unreasonable use, and that you cannot substantially impact those prior rights, those senior rights,” said Ms. Harder.  “That sounds great, but really hard to do in practice.”

So what happens with those dormant overlying rights?  Ms. Harder said the first time this question came up about extinguishment of senior rights, it first came up in the surface water context, and with surface water, riparian rights are a land-based right similar to overlying rights in groundwater. The case was the Long Valley Stream System Adjudication, and the question before the courts was how to diminish an unexercised, a dormant riparian right in the context of trying to figure out a comprehensive solution to the basin.   And the California Supreme Court said, you can’t completely extinguish those rights because there is that property right in water, but you can adjust the nature, scope, and extent of those rights.

The question then becomes, can we take that principle and take it into groundwater context and adjust the nature, scope, and extent of dormant overlying rights?  Ms. Harder noted that by ‘adjusting the nature, scope, and extent,’ what generally is meant is to subordinate the priority; you make the priority of the senior overlyer relatively junior in the allocation scheme.  In the particular case Wright vs. Goleta, the court said, not in that case you couldn’t, because that case didn’t involve a comprehensive adjudication, meaning that all water users in the basin had been noticed that somebody would be determining their rights and that they had the opportunity to come into court and protect their rights.  So outside the context of a comprehensive adjudication, you can’t subordinate those dormant overlying rights, she said.

When SGMA was passed, it was realized that this issue of dormant overlying rights was going to be problematic, so AB 1390 and SB 226 were passed the following year to address the issue.  “The legislature established a process for comprehensive adjudication of groundwater rights for the first time and said, ‘here are the rules you have to follow to protect everybody’s due process rights, make sure everybody gets notice and can come into court, and if you follow that process, in AB 1390 the legislature said to the courts, that they might think about applying the Long Valley rule now, because there is now this comprehensive adjudication’, and that’s where it stands right now,” said Ms. Harder.  “We haven’t yet had a court say, yes we’ll go ahead and apply the Long Valley Rule in the context of a comprehensive adjudication.  My opinion is that it’s quite likely that that rule will be applied and that you will have this blessing to subordinate dormant overlying rights to the extent that Long Valley allowed it, with respect to riparian rights.”

Ms. Harder also noted that in some adjudications, dormant overlyers as a practical matter have accepted limitations on their rights.  Their rights were subordinated, their future pumping to existing pumping.

These rights that I have been talking about all along here really just form the backdrop for negotiations,” Ms. Harder said.  “For the most part, different basins tend to come to different categories of solutions, depending on various factors, such as the political power and financial power of any one group of pumpers.  You tend to have the overlyers band together, the public water suppliers band together, and they tend to negotiate, and it depends on the circumstances, the political, financial, and other circumstances in the basin.  You may have dormant overlyer say, it makes practical sense for me to agree to this solution.  Those dormant overlying, those future rights may or may not be quantified as to what they can pump in the future.  There may be a future process for allowing them to start pumping.

Another thing that commonly happens is that the dormant overlyers are given access to new water that is brought into the basin to recharge the basin, and they are eligible to purchase some of that water because they are a special class, she said.


In a groundwater adjudication, there are many possible ways to resolve the dispute; it tends to be a recursive or iterative process and it is very fact specific, Ms. Harder said.  Generally, with an allocation, you would identify the safe yield, or the sustainable yield under SGMA.  Next, you would identify if you’re in overdraft, and if so, you would identify prescriptive rights holders and active overlyers.

Ms. Harder noted that there was a case law year that determined that if the prescriptive rights came up during a period of overdraft and have been identified as prescriptive rights but the basin is no longer in overdraft, those prescriptive rights don’t have to be quantified unless and until you actually get to overdraft later.  “This goes to my point that the courts and the players in these allocation practices tend to be very pragmatic,” she said.   “They tend to try not to do everything that could possibly be done, but do what needs to be done to get to a solution.”

Once the safe yield has been identified, you allocate it between active pumpers, with possibly considering a carve-out for any dormant overlyers; then you look at what is the difference between what the demand is and what the sustainable yield is. “Whatever that difference is, typically there will be somebody in charge of implementing the solution; they are usually called watermasters,” she said.  “Today they tend to be public agencies that are operated as perhaps joint powers authorities made up of different pumpers and different entities in the basin; it also could be an existing agency that has powers of management over the basin.  Somebody identifies how to bring the basin up to sustainable yield, and to do that, they augment the basin supply; they bring in replenishment water or supplemental water; I’m going to call it augmentation water.”

It is important to note that the rights to that augmented supply are different and don’t follow the same allocation rules as the native supply, Ms. Harder said.  “There is a different set of rules.  The augmented supply may be available for dormant overlyers or it may be left in place to protect basin sustainability, it can serve any number of functions.”

Ms. Harder clarified that if somebody else brings new water into the basin to augment the supply, landowners with overlying rights would not have rights to that augmented supply, unless the overlyer is participating in the augmentation solution, but unlike the right to that native water supply, they don’t automatically get it.


Ms. Harder noted that there are many challenges to the allocation.  The first challenge is that you have to decide on an allocation method for dividing water between overlying users; there are a number of approaches that have been taken over time, but there is no real guidance on one being better or more correct than another, she said.  One method would be to look at the overlyer’s historical groundwater use with the allocation based on average or highest pumping over a period of time.  Another approach would be to use the amount of irrigated acreage at a particular date; or to use the numbers of acres owned.

The next question is, how do prescriptive rights measure up as opposed to the overlying rights?  Whether they are senior or equivalent to the overlyers is a gray area in the law, and the solution has taken different approaches.

One approach is to consider the prescriptive rights to be the senior rights, and they get all the available water first, then overlyers; then if there’s anything left, the future overlyers and that would be it, if you’re in overdraft,” she said.  “The other approach is to take the prescriptive rights and the overlying rights and consider them on an equal playing field and to reduce all of their pumping almost pro rata, so that they are all reduced on some sort of equitable basis.  Right now the law isn’t very clear about which one of these approaches is correct, or whether one of them is mandated over the other.

So in summary, when we’re talking about rights to native groundwater, when you’re in overdraft, water rights still do matter,” Ms. Harder said.  “There has to be some consideration of who has those water rights and some protection for them, but what that means is unclear.  It is very fact specific, and as a practical matter, because water right holders aren’t interested in spending 40, 50 years in court and bankrupting themselves to stand on their rights and insist on a certain amount of water, they are often willing to negotiate to a practical solution, and the rights tend to rearrange themselves to honor existing pumping and to place a relatively greater cost on those who haven’t been pumping.  That’s what tends to happen.”

There are a of uncertainties and legal ambiguities; Ms. Harder pointed out some of them, noting that there are many, and this is by no means all of them.  “One of the ambiguities that happens if you have one basin that flows into another basin, and how the rights connect or not between those two connecting basins.  This is I believe causing some people a great amount of grief at the moment.  It’s unclear.”

As to the question is if two basins are connected, aren’t they one basin?, Ms. Harder noted that basin boundaries are not entirely physical; sometimes they are drawn on a political or a practical basis, such as governance lines in some instances and practicability of management, so sometimes the basin boundaries don’t track with the physical boundaries.

Mr. Williams agreed, saying that from a geologist’s point of view, basin boundaries are ‘random, arbitrary, and capricious’.  “Part of the reason is because many of the basin boundaries are developed on a surface water view of water, so they are developed around watersheds and things like that that don’t translate into the subsurface very well, so we have this historical idea of basin boundaries that doesn’t translate very well once you start to manage your groundwater.”

He also pointed out that the mantra of SGMA is that ‘groundwater is best managed locally,’ and so basin boundaries need to be a reasonable size; if not, groundwater basins could be enormous, such as from Bakersfield up to Stockton.  “If you had a basin that large, you couldn’t say ‘we are going to manage it locally’ because of the concept of locally falls apart, so we are forced into this situation of making smaller basins that we can manage with our friends and neighbors and make the basin boundaries political, and that’s how we got here,” he said.

The second ambiguity is the connection between surface water and groundwater; SGMA recognizes that connection in the definition of an undesirable result, and the need to protect against certain significant and unreasonable depletions of surface water that has certain impacts, said Ms. Harder.  “The question about how we’re going to integrate all of that and how we reconcile surface water flow, groundwater flow, surface water rights and groundwater rights, that still is obviously a major ambiguity that we’ll be dealing with going forward.”


Ms. Harder then discussed court adjudication and the Sustainable Groundwater Management Act.   Adjudications of groundwater basins can occur to varying degrees, from a full comprehensive adjudication with numerous parties in court to just a subset of parties involved.

Adjudications are essentially a negotiated solution developed through phases of the trial where different parameters are identified.  First the basin boundaries are identified; then if the basin is in overdraft; prescriptive rights are identified; the safe yield is determined, and an allocation is made going forward.  In that allocation, they may or may not define and quantify individual rights or they may group rights according to classes.  There may be a process framework set up.   That negotiated solution is blessed by the courts as a stipulated judgment.

After the enactment of SGMA in 2014, processes were set up to allow court adjudications to go forward taking the SGMA process into account.  “The legislature hasn’t required the courts to do anything in particular, there are concerns about separation of powers, and tricky little things like that,” Ms. Harder said.  “But there are provisions in the law that say that the court can, for example, stay adjudication proceedings or put them on hold to allow the SGMA process to play out.  The court should consider the sustainability plan that’s been developed in the SGMA process as it looks at its adjudication allocation.

Pre-SGMA, undesirable results were something that drove the identification of your basin being in overdraft, but there’s no requirement, and often it’s not done, that after adjudications, you actually fix the undesirable result,” said Mr. Williams.  “You usually fix the undesirable result of amount of water in storage, because with the water budget, you’re saying we have to cutback the pumping to keep water in storage, and that’s how you move forward, but things like streamflows or subsidence are specifically lined out in some of these.”

However, as SGMA goes forward, the requirement is you manage the basin to avoid these undesirable results, so it’s a slightly different view of things,” Mr. Williams continued.  “It is not that we have to maintain our pumping to meet a specific safe yield, we have to maintain our whole management to avoid six undesirable results. … DWR has made it fairly clear that if you have no undesirable results in your basin, by definition, you’re pumping within the safe yield.  That’s the definition, so it goes backwards from now on.”

The main issue is that before, we were thinking on a basin-wide scale and how do we bring the basin into balance?” Mr. Williams said.  “Going forward now, we’re talking about local issues.  Not just how do we bring the basin into balance, but avoid impacts on a particular stream and avoiding subsidence in a particular area, so the water rights now have to start thinking not just about everybody’s correlative right, but how you deal with particular local issues that certain landowners will be more impacted than other landowners.”

Addressing localized pumping impacts is going to be a shift, agreed Ms. Harder.  “You may be able to say you have this total number for your sustainable yield or safe yield, and in the past, we would have managed to that big number, but now we’re going to have to say even if overall we’re doing that, this fellow over here is still pumping in a manner that significantly and unreasonably affects groundwater dependent ecosystems, the surface water ecosystems, so that person is probably going to have some restrictions on pumping even if at a basin-wide level, that wouldn’t have been taken into account in the past.  You’re going to see that kind of shifting going forward.”


Another issue is the accuracy of data; Mr. Williams said that there isn’t really any basin that has enough data to show the undesirable results; the one that’s easiest is groundwater levels.  “The one that everybody worries about is the impact on groundwater dependent ecosystems and interconnected water bodies, because the amount of data available to quantify that in any degree at all is sparse and questionable.  So some of the undesirable results, we will be able to assess, and there are some that will be very, very difficult to assess.”

The data collection issue implicates some fairly substantial institutional and financial issues,” said Ms. Harder.  “We need some people who can think in a smart way about how to marshal financial resources and how to structure institutions so that they are capable of collecting data.  They have the resources to collect that data, but also to know what data to collect, how to organize it and how to process it, so that we’re not just simply collecting data for the sake of collecting data, but we’re doing it in a way that actually helps what we’re doing.”

Both Ms. Harder and Mr. Williams acknowledged the work that the Nature Conservancy has done on groundwater dependent ecosystems, which includes statewide maps.  (Click here: Groundwater Dependent Ecosystems)

Mr. Williams noted that the real problem will be coming up with local opinions of what is significant and unreasonable for these GDEs.  “Is it significant and unreasonable that we dry out half of them?  Is it significant and unreasonable that we dry out any of them?,” he said.

Ms. Harder added that from a legal perspective, reasonableness is a relative concept.  “It is very fact specific, it is very time specific, and it is something that can change with circumstances of water availability and over time, so there isn’t a clear yes, this is unreasonable or no, this is isn’t,” she said.  “It’s a much more nuanced assessment.”


When working to reach sustainable yield, the method generally is to identify the deficit needed to get to sustainable yield.  Once identified, there are a number of ways to correct the problem.  One way is to reduce pumping, which is controversial as well as politically difficult, but it will probably be needed in some basins, said Ms. Harder.  Because of the political difficulties, the more common approach is to seek to bring in new water that can augment the supply and bring the basin up to sustainable yield.

The goals here are to meet active pumping needs, avoid those undesirable results, and for those dormant pumpers, lately the trend has been to give them access to the augmentation water by them then paying into purchasing some of that water,” she said.

It’s important to remember that the rights to augmented supplies are different from the rights to the native supplies; there’s a whole separate scheme of property rights that attach.  There are different categories: one is developed water, and the other is salvage water.

The idea of these categories is that you have water that previously may have run off which is now being captured in storage and added to the basin; it’s like the idea of surface water reservoirs taken to the groundwater basin,” Ms. Harder said.  “The idea of salvage water would be more along the lines of recycled existing supply that otherwise would not have been returned to the basin and using that to augment the basin.  There’s a general rule that even though the augmented rights are separate from the native rights, there’s an obligation in the context of the augmentation scheme to not injure native rights in terms of affecting their access to quantity or quality, so that’s one obligation that applies.”


With respect to supplies for augmentation water, there are a number of possible sources.  There’s surface water, stormwater capture, very highly treated wastewater, or even seawater desalination.  Mr. Williams noted that particularly along the Central Coast, and down on the South Coast these days, it’s starting to pencil out; although its expensive water, it’s worth it because all water is expensive now.

There are a few approaches to getting the augmented water into the basin:

Percolation:   Mr. Williams presented a picture of a percolation pond in the Santa Clara Valley where Santa Clara Valley Water District uses percolation ponds to infiltrate water into the aquifer.  He noted that the water district takes credit for all the percolation in the stream bed from the reservoir to the pond; Orange County does this as well.   “If you don’t have any environmental constraints like fish flows or something like that, you’re best plan is to put enough water in the stream that the stream is dry at the end and basically everything has percolated in,” he said.

Direct injection:  This is also referred to as ‘aquifer storage and recovery’.  It’s a relatively expensive way to go, but it does have some advantages, Mr. Williams said.

In lieu recharge: In lieu recharge is the process of replacing groundwater supplies with surface water supplies, thereby letting the groundwater that would have otherwise been pumped remain in the ground.  Typically the decrease in groundwater pumping occurs in wet years when surface water supplies can be delivered ‘in-lieu’ of groundwater pumping.

Ms. Harder noted that there is a provision in the water code that says that if you wish to claim a right to in-lieu recharge, you can go through a process to document that with the State Water Resources Control Board, therefore you avoid forfeiting whatever right it is you’re not using, and there is some claim on that water, now that you’ve recharged it, if you go through the State Board process.  “This law was actually enacted after the Supreme Court came up with the whole prescriptive rights theme, because they were afraid people were going to start pumping like crazy in order to protect their rights from prescription, and so they wanted to give them some sort of ability to protect that right,” she said.

However, there are a number of basins around the state and projects within basins that depend heavily upon the concept of in-lieu recharge and the right to access that water; and there are some groundwater banking operations and management frameworks that depend on in lieu recharge.  As a matter of practicality, the rights to that water is settled in those areas because of who is managing the basin, who is pumping, and what the demands are on the water, she said.

Does that translate into any individual water user being able to say, ‘I didn’t pump and therefore you can’t access the water that I would have pumped?’  “I think that’s challenging, because there is a case that talked about rights to the groundwater storage space, and the right to storage space is considered distinct from the right to the water supply,” said Ms. Harder.  “The court said, at least in the context of this case, that the overlying landowners did not automatically have a right to that storage space; that the storage space is a public resource and might be allocated otherwise.  One of the claims was if you have a public agency who is charged with managing that basin, they have some sort of right to claim the storage space for public values, to promote these public values and public good, so just even looking at it from that slice, I would say it would be difficult for the individual pumper to say, I’m hereby claiming this storage and keeping that water in storage in perpetuity.  There are a lot of other pieces that come into that.


With the rights to augmented supply, depending upon how your augmentation project is structured, if it involves surface water rights, you may or may not need permits or some other permissions in order to conduct that project. Ms. Harder said.  The State Water Resources Control Board has jurisdiction over appropriative surface rights after 1914, so if your project involves those kinds of rights, you need permission from the State Water Board.  If the surface water rights are riparian, land-based in nature, or pre-1914, the right to use the riparian right is limited in these kinds of projects; pre-1914 water rights, you don’t need the board’s permission, she said.

Ms. Harder noted that another continuing area of discussion is the fact that recharge of groundwater and recharging any water to groundwater is not considered a beneficial use in and of itself; the beneficial use which is critical to all water use in California occurs when it applies to the ultimate end use, such as municipal use or agricultural use.  “This is a rule that grew up out of the surface water framework and the concept of storage in reservoirs, so you don’t consider that water to have been beneficially used until it is applied to the ultimate use,” she said.

Ms. Harder acknowledged that there are some circumstances in which the ultimate use might occur in-place when in storage.  For surface water reservoirs, that can happen when there are recreation reservoirs that hold water in storage for recreation for beneficial use; similarly, for groundwater, the beneficial use may occur when water is put into the ground in order to repel seawater intrusion.

That’s a water quality beneficial use that can occur in place, but this issue of when the beneficial use occurs and the facts that you can’t just put water in the ground just to put it in the ground, has been the source of some consternation, “ Ms. Harder said.  Mr. Williams agreed, saying that groundwater hydrologists have been trying to figure out a way to get some legislation to make groundwater recharge a beneficial use, but it’s going very slowly.

Ms. Harder said the need to identify a beneficial use is strongly ingrained in the law, something that comes from an ancient concept in water law, the maximum use principle, which attempts to squeeze out of every drop of water value for society.  “One of the earliest rules in water law was that you cannot allow people to hoard water or to essentially claim the water resource and put it away so that they can sell it to other people at exorbitant prices, and therefore deprive the rest of society of the benefits of that water, so we have this anti-hoarding rule,” she said.  “That’s actually the genesis of this idea.”

Ms. Harder then briefly summarized.  “The rights are different to the augmented supply then they are to the native supply and you have to carefully trace the source of the augmentation water to figure out what legal rules do apply,” she said.  “There is some responsibility when you are augmenting the basin supply to avoid injury to those existing water users.  One of the biggest political issues with projects to recharge groundwater actually comes from some of those users who feel worried that when the water, for example, is pulled out of the basin, it’s going to negatively impact their well water, so with some of these projects, like groundwater banking projects, you see requirements to leave some water in the basin when you pull out your augmented supply, an offset, essentially.”


Review the following pumping activities within the Trelease Groundwater Basin (Trelease Basin) in California, and answer the questions that follow.


1. Weber Farms owns property that is located over the boundaries of the Trelease Basin. Since 1950, Weber Farms has pumped 10,000 acre-feet per year (AFY) of groundwater from this property to irrigate a large acreage of various crops located on the property (carrots, basil, tomatoes).

2. Schaber Farms also owns property located over the Trelease Basin, consisting of approximately 5,000 acres that has not yet been cultivated. Schaber has plans to develop the property into almond orchards or a similar venture, depending on the market, in 5-15 years. Schaber plans to supply the property’s future estimated irrigation demand of 10,000 AFY by installing wells on the property.

3. The City of Robie is also located over the Trelease Basin. Since 1975, the City has been pumping groundwater as its sole water supply, increasing its use from 6,000 to 20,000 AFY over that time.

4. The City of Gould is also located over the Trelease Basin. Since 1939, the City has been pumping groundwater as part of its water supply portfolio, increasing its annual use from 2,000 acre-feet to 20,000 AFY over that time.

5. Hidalgo Properties, a real estate develoent firm, owns several properties overlying the Trelease Basin. One of these is a 5,000 acre undeveloped parcel on which Hidalgo located a series of wells in 2010. Since 2010, Hildago has pumped 10,000 AFY from these wells and conveyed the groundwater via pipeline for five miles to a separate Hildalgo property that is located outside the boundaries of the Trelease Basin, at which location the water is used to irrigate almond orchards.

For Questions 1-10, assume that the Trelease Basin as not been determined to be in overdraft, and that the safe yield is unknown.

1. The water right for Weber Farms is:

a. Overlying
b. Dormant Overlying
c. Appropriative
d. Prescriptive

Click for answer.

Overlying: Weber Farms is located over the boundaries of the basin and using water on that property.

2. The water right for Schaber Farms is:

a. Overlying
b. Dormant Overlying
c. Appropriative
d. Prescriptive

Click for answer.

Dormant overlying.  Schaber Farms is not pumping at this time.

3. The water right for the City of Robie:

a. Overlying
b. Dormant Overlyin
c. Appropriative
d. Prescriptive

Click for answer.

Appropriative. If the basin is not in overdraft, public water agencies and cities are considered appropriators.

4. The water right for the City of Gould:

a. Overlying
b. Dormant Overlying
c. Appropriative
d. Prescriptive

Click for answer.

Appropriative. If the basin is not in overdraft, public water agencies and cities are considered appropriators.

5. The water right for Hildago Properties:

a. Overlying
b. Dormant Overlying
c. Appropriative
d. Prescriptive

Click for answer.

Appropriative. Hidalgo is pumping water and conveying it to properties outside the basin.

6. Which party or parties have the first priority water right(s) in the Trelease Basin? Select all that apply.

a. Weber Farms
b. Schaber Farms
c. City of Robie
d. City of Gould
e. Hidalgo Properties

Click for answer.

Weber Farms and Schaber Farms, because they are both overlyers, even though Schaber is a dormant overlyer.

7. Which party or parties have the second priority water right(s)? Select all that apply.

a. Weber Farms
b. Schaber Farms
c. City of Robie
d. City of Gould
e. Hidalgo Properties

Click for answer.

City of Gould, because the other three are appropriators; therefore the priority system applies and the city of Gould has the earliest pumping dates.

8. Which party or parties have the third priority water right(s)? Select all that apply.

a. Weber Farms
b. Schaber Farms
c. City of Robie
d. City of Gould
e. Hidalgo Properties

Click for answer.

City of Robie, which has the next senior pumping date.

9. Which party or parties have the fourth priority water right(s)? Select all that apply.

a. Weber Farms
b. Schaber Farms
c. City of Robie
d. City of Gould
e. Hidalgo Properties

Click for answer.

Hidalgo Properties has the last priority as they were the last appropriator to begin pumping.

For questions 10-14, assume that Trelease Basin is in overdraft and in a 2017 adjudication is determined to have a safe yield of 50,000 AFY.

10. Which parties are most likely to claim prescriptive rights?

a. Weber Farms
b. Schaber Farms
c. City of Robie
d. City of Gould
e. Hidalgo Properties

Click for answer.

The City of Robie and City of Gould are most likely to claim prescriptive rights.  Hidalgo is an appropriator and has been pumping, so Hidalgo is also likely to claim prescriptive rights as well.

11. Who is most at risk at being subordinated to prescriptive rights?

a. Weber Farms
b. Schaber Farms
c. City of Robie
d. City of Gould
e. Hidalgo Properties

Click for answer.

Schaber farms as the dormant overlyer.

12. Which of the following represents the most appropriate allocation of the 50,000 AFY safe yield between overlying rights and prescriptive rights?

a. The City of Robie, the City of Gould, and Weber Farms should be allocated 10,000 AFY each, and Schaber Farms and Hidalgo Properties should be allocated zero.
b. To correct overpumping from 70,000 AFY to 50,000 AFY, each of the five users should be allocated their current demand minus 4,000 AFY.
c. The “correct” allocation is legally uncertain and typically a matter for negotiation; the ultimate allocation must not substantially violate water right priorities against the will of those who hold affected water rights.
d. The City of Robie and the City of Gould should be allocated 25,000 AFY each to
accommodate their current needs and growing populations.
e. None of the above.

Click for answer.

Answer: C: The “correct” allocation is legally uncertain and typically a matter for negotiation.

13. Assume for purposes of this question that the City of Robie imports water from another watershed and supplies that water to its residential customers. The City then recycles that water at its municipal wastewater treatment plant and recharges the recycled water to the Trelease Basin. Which of the following is a true statement?

a. Weber Farms has the right to pump all of the recycled water recharged by Robie.
b. The City of Robie can claim an overlying right to the recycled water.
c. The City of Robie has exclusive right to the recycled water except to the extent that
pumping the water might affect the rights of other groundwater users to the native supply.
d. All of the groundwater pumpers in the Trelease Basin must share the recycled water on an equitable basis.
e. None of the above.

Click for answer.

Answer C.  When we talk about concepts of injury and no injury and the right to reclaimed water, the obligations may differ if the source of water is imported from outside of the watershed versus whether it originated in the watershed.  One of the things to keep in mind when thinking about augmentation supplies is did that supply originate in the basin?  If it did, the calculation of who has exclusive right to that water and how much that exclusive right is may shift.

If you have a city that is using water that is native to the basin, serving that to residents, treating that and then recharging it, that water may have ultimately ended up in the basin even absent the recycling program, and so the city can’t necessarily claim an exclusive right to that water.  There’s some amount that has to be accounted for as native to the basin.  But if that water comes from outside the basin, the city has more ability to claim an exclusive right unless withdrawal of that water or storage of that water would injure the native water users, and that’s very fact specific.

14. Assume for purposes of this question that the City of Gould stores water that originates in the Trelease Basin watershed, and releases that water into Trelease River wherein that water then percolates through the riverbed into the Trelease Basin. Which of the following is a true statement?

a. The storage release that percolates into the Trelease Basin becomes part of the native groundwater supply and must be allocated according to groundwater priorities for native supply.
b. Some portion of the storage release that percolates into the Trelease Basin might be part of the native supply, and another portion might belong exclusively to the City of Gould.
c. The storage release that percolates into the Trelease Basin belongs exclusively to the City of Gould, and the City can pump that water without regard to native groundwater users.
d. The storage release that percolates into the Trelease Basin must be left in storage to correct overdraft, and cannot be withdrawn.
e. None of the above.

Click for answer.

Answer B.  The reason why is there’s a rule in California that when somebody invests in developing a water supply by creating a storage facility and capturing water that would have otherwise been lost, they have the right to that water, so if you’re storing water in the reservoir and you’re releasing it and it’s recharging the basin, that water stays your water because you stored and invested in it.  One question is, of the amount in storage, is all of that water properly allocated to storage or would some of that water have been native to the system anyway?  The point being you have to account for what would have been in the basin and watershed naturally when you’re figuring out who has rights to the augmented supply.



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