Guest Column | September 15, 2014

Tackling The Drought: The Relationship Between Water Law And Water Budget

By Kai David Midboe, Director of Policy Research And General Counsel, The Water Institute Of The Gulf

Natural resource management usually involves more than science and engineering, it intersects law, policy, and politics.  Nowhere is this truer than in the regulation of water.

The United States is in one of the worst droughts since the Dust Bowl of the 1930s and the Southwest drought of the 1950s.  The current drought affects over half the country, with an estimated 73 million people – 20 percent of all Americans – living in moderate to exceptional drought conditions.  Particularly hard hit is the state of California, where there is talk of a “mega drought.”  A mega drought is defined more by its duration than severity, where extreme dry spells can last a decade or longer.

Virtually all users draw their water from streams, lakes, reservoirs, or groundwater resources.  As drought conditions have intensified, states have begun to take a closer look at the sustainability of these critical sources of water.  What they are finding is disturbing.  First, the overall rates and magnitude of surface water withdrawals and groundwater depletion are not well understood.  Second, and more importantly, there appears to be a chronic imbalance between water supply and water demand.

In California, for instance, researchers found that over the last century authorities have issued withdrawal rights for roughly five times as much surface water as the state’s average annual surface water runoff – an enormous gap between natural surface water flows and allocations.  The over-allocation of surface water also exists in many other states.

Many groundwater aquifers are also being used at unsustainable rates.  This includes such critical sources of water as the Ogallala and Edwards aquifers.  The Ogallala aquifer has experienced the largest decrease in water storage of any major aquifer in the nation.  In parts of the central and southern High Plains, more than 50 percent of the predevelopment saturated thickness of the aquifer has been dewatered. 

Groundwater is one of the nation's most important natural resources.  It is the source of about 33 percent of the water supplied to urban households and businesses and provides drinking water to more than 97 percent of the rural population.  Unfortunately, a recent study shows that the current drought is having even greater impacts on groundwater resources than previously expected.  In the Colorado River Basin, three quarters of the water lost due to the drought has come from groundwater.

Water stored in the ground is like money kept in a bank account.  If you withdraw money faster than you deposit it, you will eventually deplete your assets.  Pumping water out of the ground faster than it is replenished will cause similar problems.  The harmful effects of groundwater depletion can be many – the drying up of water wells; reduction of water in streams, lakes and wetlands; deterioration of water quality; increased pumping costs; and land subsidence. 

Overuse of water can affect not only water supply for human consumption, but also maintenance of the “in stream” flows required for fish habitat and other environmental needs.  Long-term reductions in stream flows can further affect the vegetation along streams that serve critical roles in maintaining wildlife habitat and in enhancing the quality of surface water.   The water needs of ecosystems have become an integral part of water management.

Conflicts over the use of scarce water resources are growing.  Florida, Georgia, and Alabama are currently in court fighting over the allocation of water from the Apalachicola-Chattahoochee-Flint river systems; Texas, New Mexico, and Oklahoma are in disputes concerning water from the Rio Grande and Red River; there are fights by users over the allocation of water from the Ogallala and Edwards aquifers; one well know entrepreneur is proposing to corner the market on selling scarce Texas water; and the list goes on. 

Unfortunately, the future portends only greater competition for water, primarily because there will be more people.  This has brought calls for increased water regulation.  Even in my state of Louisiana, which is traditionally viewed as blessed with water, the Senate has demanded the development of a Water Code.

Water law describes the body of law governing the use and control of water.  The United States has evolved multiple, complex legal systems for regulating water.  The systems vary by federal, state and local jurisdictions; and even by region of the country.  The different approaches developed largely because of differences in the supply and needs for water across the country.  For instance, two fundamentally different legal systems have developed governing the allocation and use of surface water.  These two systems are roughly divided at the Mississippi River – the eastern United States governed by the “riparian ownership rule;” and the western United States governed by the “prior appropriation rule.” 

The riparian ownership rule is based on English common law.  The basic concept is that private water rights are tied to the ownership of land bordering a natural river or stream.  Riparian landowners have a right to use the surface water, provided the use is reasonable in relation to the needs of other riparian owners.

Groundwater law has arisen quite separately.  Early on, little was known about the movement of groundwater, particularly its hydrologic relationship to surface water.  In the eastern states, a “rule of capture” was developed, establishing no liability and ownership of groundwater in landowners who reduced the water to physical possession.  In the drier, western half of the nation, they developed the concept of “prior appropriation.”  This concept prioritized the private right to water (surface and groundwater) based on who first diverted it and put it to a reasonable and beneficial use.  Over time this practice became legalized and incorporated into statutory law as the prior appropriation rule.  The prior appropriation rule is not related to land ownership, instead water rights are acquired by compliance with the statutory law.  It is largely a “first in time, first in right” approach to water management. 

States now have a somewhat better understanding of the hydrology of water systems.  They understand that groundwater and surface water are often interconnected – withdrawal of water from one often results in a direct reduction in water from the other.  This has led to various approaches to the allocation of groundwater, including such common law doctrines as: (1) the rule of capture; (2) the “American” reasonable-use doctrine; (3) the correlative rights doctrine; and (4) the Second Restatement of Torts’ doctrine of reasonable use.  

But there is one thing these doctrines all seem to have in common – they have proven ineffective at preventing the unsustainable use of water.  Having different water management systems for surface water and groundwater, where the waters are often treated by law as not being connected, has particularly hampered resolving this unsustainability.

Making changes to existing water law will be controversial.  Because water is vital to all living things, and most economic activity, the laws and policies governing water can have far-reaching effects.  Water has unique features that make it very difficult to regulate.  Water is mobile, linked through the hydrologic cycle, and often not confined within a single geographic boundary or political jurisdiction.  Its supply can vary by year, season or location.  A source of water can have many users, often leading to bitter conflicts over uses.  Determining who owns water – or has the right to manage, divert, use or sell it – can become very contentious.  Attempts to regulate water often lead to claims of the “taking” of private property. 

To properly regulate water, states need certain critical information.  They need to know the amount of water that is there; where it is located; what is its input, output and movement of through surface and groundwater; how much is available for various uses (both natural and human); what are the current and potential uses; and, importantly, what is its future sustainability?  In other words, the states need a Water Budget.

A Water Budget provides the means for evaluating the availability and sustainability of water supplies.  It is the foundation of effective water management.  However, most states (including Louisiana) don’t have a Water Budget.

According to the U.S. Geological Survey (USGS), Water Budgets account for the inputs, outputs, and changes in the amount of water by breaking the water cycle down into components.  They provide scientific measurements and estimates of the amount of water in each component and calculate the movement of the water through the different components.  The basic components of Water Budgets are precipitation, evapotranspiration (the upward flux of water from the land surface to the atmosphere, a combination of evaporation from the soil and transpiration by plants), surface water flows (such as streams and lakes) and groundwater flows (aquifers) into and out of the watershed, changes in surface water and groundwater storage, changes in snow and ice storage, and the impact of human withdrawals and inter-basin transfers.

Water Budgets provide a way for science to intersect with the law, policy and politics of water.  According to the USGS, as with a monetary budget or checking account, knowing where, when, and how much is flowing into or out of an account can provide a means for calculating how much is left for other uses (water availability) and where stresses to the budget (the unpaid bills or water shortages) exist or are developing. 

Water managers want to know how much water they have, how much water they use, and how, when, and at what rate water supplies are replenished.  Water Budgets provide a scientific basis for assessing how human activities affect the hydrologic cycle.  They help regulators determine which current and projected uses of water are sustainable and which are not.  Water Budgets provide a defensible basis for the informed planning and management of various uses of water. 

The Water Institute has proposed to use its independent research capability to help Louisiana develop a Water Budget.  The Water Budget would be used to scientifically inform the drafting of the state’s new Water Code.

Kai David Midboe is the director of policy research and general counsel at The Water Institute of the Gulf. The Water Institute of the Gulf (Water Institute) is an independent research organization dedicated to advancing the understanding of water resource systems, both within the United States and around the world.  It strives to support the wise and sustainable use of water.  Organized under Section 503(c)(3) of the Internal Revenue Code, the Water Institute cannot earn a profit, lobby or engage in politics.  Its research must be truly independent and dedicated to the public interest.  Furthermore, its research is applied research, meaning it is intended to inform decision makers. Kai David Midboe is also the Former Secretary of the Louisiana Department of Environmental Quality.


U.S. Geological Survey (USGS), Water Budgets: Foundations for Effective Water Resources and Environmental Management (Circular 1308) at; and

Drought Monitor at

Mark Davis & James Wilkins, A Defining Resource: Louisiana’s Place in the Emerging Water Economy, 57 LOY. L. REV. 273 (2011)

Water Online at and drought at