Environmental Engineering Reference
In-Depth Information
other natural resource held in common, an aquifer tends to be viewed by individuals pursuing their
own self-interests as a resource to be exploited before others are able to get to it” (Ponce 2006).
Some states, for example, California, have provisions to the water doctrines called “use it or lose it,”
such that if the owner does not use the water, someone else may acquire prescriptive rights. Classic
examples resulting from the tragedy of the commons include:
Borrego Valley, in Southern California's high desert, near Borrego Springs, in San Diego
County. Water levels in Borrego Valley have declined 2 ft. per year (0.6 m yr -1 ) over the
past 20 years.
South-central Arizona, where groundwater pumping to support the population growth,
including the Tucson and Phoenix areas, has resulted in water-table drops of between 300
and 500 ft. (90 and 150 m) and land subsidence of as much as 12.5 ft. (3.8 m).
3.6.2.3 Sustainability, Conjunctive Use, and Water Law
One of the foundations for holistic water management is the hydrologic cycle, discussed in
Chapter 1, and the connectivity between each of the components of that cycle. One of those compo-
nents is the connectivity between surface water and groundwater as it impacts the lows in streams
and rivers (see Figure 3.30). Another issue in water management and law is achieving the goal of
sustainable use. Sustainability has been variously deined, but one deinition applicable here is:
Sustainability is the ability to meet current needs without compromising the ability of future genera-
tions to meet their needs.
Generally, to attain sustainability a holistic approach to water law and management is required,
or, at a minimum, recognizing the connectivity between surface water and groundwater, commonly
referred to as conjunctive use or management (OWRB 2012).
States generally have water laws that impact both surface water and groundwater. However,
states may or may not recognize the connectivity between the two, or have laws that allow for
conjunctive use. Texas, for example, has a surface water permit based where the surface water is
publicly owned and governed by the state of Texas and a permit from the state is required for any
water use other than for domestic or livestock use. However, unlike surface water, in Texas the
groundwater is the property of the landowner, under the rule of capture or the absolute ownership
rule. Similarly, Louisiana also uses the rule of capture for regulating groundwater.
As an example, one of the more ecologically important rivers in southern Arizona is the
San Pedro River, located just south of Sierra Vista. It is the last major, free-lowing undammed
desert river in the American Southwest, and hosts two-thirds of the avian diversity in the
United States. It also includes the 40-mile long San Pedro riparian natural conservation area
created by Congress in 1988 (Figure 3.31). Groundwater depletion in the area has long been
an issue, impacting the lows in the river. A plan for a 5900-home subdivision in the area was
proposed, but a number of agencies and organizations opposed the plan because of its impact
on groundwater depletion and on the river lows. However, in Arizona, water laws for sur-
face water and groundwater are separate and do not recognize connectivity between surface
water and groundwater and do not consider environmental needs (Megdal, et al. 2011). Under
Arizona's Groundwater Management Act (GMA; Megdal et al. 2011), developers are required
to demonstrate an assured water supply, which, according to this act, is to demonstrate that “a
100-year water supply to satisfy the subdivision's needs is physically, legally, and continuously
available.” A study by the developer, as reported in the Arizona Daily Star (August 30, 2012),
indicated that the projected impact of the development would not lower the water table by more
than 1200 ft. over the next 100 years. This met the requirements of the GMA, and since envi-
ronmental impacts and connectivity could not be considered by law, as reported by the Arizona
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