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In 1864, the first territorial legislature of Arizona adopted the prior appropriation system for surface water rights. By the late 1800's, severe water shortages along Salt and Gila Rivers resulted from rapid development or irrigated agriculture combined with drought years. On June 12, 1919, the legislature established the State Water Code. This Code requires water rights applications to be filed with a state administrative agency (currently ADWR). If all requests are met, the permit and certificate of water right are issued. In accordance with the Prior Appropriation Doctrine, all certificates of water right are subject to prior water rights. The 1919 Public Water Code set forth guidelines for defining appropriable waters. The 1919 Code states that "the waters of all sources, flowing in streams, canyons, ravines or other natural channels, or in definite underground channels...belong to the public and are subject to appropriation and beneficial use." The Arizona Supreme Court characterized a watercourse as having "a channel, consisting of a well-defined bed and banks, and a current of water." The law made no distinction between surface and underground channels.
In a landmark case, Maricopa Co. Municipal Water Conservation District v. Southwest Cotton Company (1931), the Arizona Supreme Court identified characteristics of an underground stream and adopted a test to determine the appropriability of a stream's "subflow." The Court defined "subflow" as "those waters which slowly find their way through the sand and gravel constituting the bed of the stream, or the lands under or immediately adjacent to the stream, and are themselves a part of the surface stream." The Court described the test of appropriability of the subflow with a question: "does drawing off the subsurface water tend to diminish appreciably and directly the flow to the surface stream?" If so, the water is appropriable "subflow," otherwise underground waters are not appropriable.
On June 12, 1980, the Arizona legislature enacted a comprehensive groundwater management code governing the allocation and use of groundwater. This legislation was a direct product of Arizona's continued overdraft of groundwater. The 1980 Code created four Active Management Areas (AMA's) with specific regulations on groundwater pumping and two Irrigation Non-expansion Areas (INA's) in which expansion of irrigated agriculture is prohibited.
Outside of AMA's and INA's, the beneficial use rule applies to groundwater rights. That is, anyone may pump water from below his property as needed for a beneficial use on that property. As of this date, no AMA or INA has been defined in the San Pedro River watershed, so the only restrictions that apply to drilling wells or pumping groundwater are the requirement of well registration and conformity to well construction standards. The ADWR (1990) reports 5,298 registered wells on file with the ADWR in San Pedro River watershed.
Court decreed water rights are those determined by state or federal court. Such court action is usually initiated by a water user who wants to clarify his right relative to others', or in the event of a rights conflict between users, or as part of a general adjudication. The court process confirms or denies the validity of previously granted rights, and ranks rights by priority. Decrees may also quantify or prioritize rights for the first time. In the event of a conflict over a limited water supply, the decree may include a formula for distributing the available water, monetary mitigation of the conflict, or other solutions imposed by the court. Court decreed rights are considered the most certain because they are not subject to redetermination or challenge.
Currently, three major water right decrees exist in the Gila River System. Six known water right decrees have been established in the San Pedro watershed, all of which affect a small number of users.
Federal water law is based primarily on case law determined over many years in federal court decisions. Four U.S. Supreme Court cases pertain directly to the Gila River adjudication, and thus to water rights in the San Pedro River Basin:
1) Winters v. United States (1908) - Now known as the "Winters Doctrine." The Court found that an Indian reservation may reserve enough water to irrigate all of the "practicably irrigable acreage" on the reservation with a priority dating from the treaty, act of Congress, or executive order that established the reservation. These "reserved rights" are based on a reservation of water by the federal government.
2) Arizona v. California (1963), (1979), (1963) - Confirmed the division of the waters of the Colorado River among lower basin states. The court quantified the reserved rights of five Indian reservations on the basis of an amount of water necessary to irrigate "all practicably irrigable acreage" (PIA) on the reservation. This practice is now known as the PIA method of quantifying reserved rights.
3) Cappaert v. United States (1976) - Determined that federal reserved rights can be protected from infringement by junior users of groundwater and supported the extension of federal reserved water rights to other federal lands set aside for specific federal purposes. In this case, the federal government reserved water right consisted of enough water to maintain Devil's Hole in Nevada, an unusual underground pool that sustains a population of the endangered desert pup fish. The pool was set aside as a National Monument by President Truman in 1952, and the Court acknowledged that the federal water rights originated from that date. This issue substantiates the case that the reserved rights doctrine will apply to the San Pedro Riparian National Conservation Area. The Cappaert case also established that when a dispute exists between state and federal interests, federal rights take precedence. On the other hand, the ruling implied that the federal right reserves only "that amount of water necessary to fulfill the purpose of the reservation, no more." The Court also held that federal reserved rights can protect water from subsequent diversion, whether the diversion is of surface or groundwater (Glennon and Maddock, 1992).
4) United States v. New Mexico (1978) - Established that reserved water rights on national forests apply only to the preservation of timber resources and water flows, and cautioned that the quantification of reserved rights should consider the potential effect on downstream junior state right appropriators (Putman, et al, 1988). The Court addressed the question of how much water the United States had reserved out of a particular river as "necessary" for the purposes of the federal reservation. In this case, a national forest constituted the federal reservation, so the Court focused on the primary purpose of the reservation. In the end, the Court's decision sent no clear message to future determinations of similar cases (Glennon and Maddock, 1992).
Other court decisions have extended the reserved right doctrine to certain water uses in national forests, national parks and monuments, military reservations, and BLM lands.
Federal law claims in the San Pedro River watershed have been filed by the Arizona State Land Department (SLD), Coronado National Forest, Coronado and Saguaro National Monuments, Fort Huachuca, the BLM, and the San Carlos Apache Tribe. Downstream of the San Pedro watershed, the Gila River Indian Community has filed a very large claim including rights to waters originating in the San Pedro River watershed (ADWR, 1990).
The purpose of the Gila River Adjudication is to consolidate all diversely created and
administered water rights into a single comprehensive determination of all rights. The adjudication proceeding resulted from the over-appropriation of surface water in the Gila River system, groundwater overdraft, and growing municipal water use. The types of existing water rights in the system include:
Surface Water- Prior to statehood, surface water rights were established by putting the water to a "beneficial use" or posting a notice of intent to use the water. After statehood, a permit system was invoked. Few surface water rights have ever been examined for validity, nor have restrictions on those rights been enforced.
Groundwater- Prior to 1980, any landowner could withdraw groundwater from under his land for beneficial use with no posting or permit. Several thousands of surface water and groundwater rights claims are on file with the state, but the status of many is unknown. Many other rights were established by court decrees, but few of these are actively administered or tracked. Federal water rights are also claimed by the U.S. Government and by Indian tribes. Most of these rights are not yet prioritized or quantified.
The adjudication of the San Pedro River watershed began on April 3, 1978 when the American Smelting and Refining Company petitioned the Arizona State Land Department (SLD) for a resolution of conflicting rights. This action led the SLD to call for over 6700 land owners within the San Pedro River watershed to file statements of claims as part of the San Pedro River watershed adjudication.
In February, 1979, the State Legislature replaced the statutes governing adjudications with the current statutes, effectively transferring jurisdiction of all pending and future adjudications to Arizona Superior Court, with the Arizona Water Commission as the court's technical assistant. In 1981, the Arizona Supreme Court consolidated several separate adjudication proceedings within the Gila River System into one. The Court then assigned the Maricopa County Superior Court to handle the adjudication.
June 1978, the Gila River Indian Community filed suit in federal district court seeking a declaratory judgment that it had first priority to the use of all waters in San Pedro River watershed, including groundwater. Two other similar law suits were filed in federal district court by Indian tribes involving other Arizona watersheds. In all three cased, the federal courts delayed or dismissed the suits in favor of the determination of the tribes' rights in state court. The Indians appealed to a higher federal court which, in turn, eventually led to a U.S. Supreme Court ruling in 1983 that the Federal District Court was correct in deferring to state proceedings.
After the U.S. Supreme Court ruling, the Gila River adjudication continued, with Judge Stanley Z. Goodfarb presiding. He set a deadline for filing groundwater claims and put forth orders directing procedures for conducting the adjudication, including the establishment of a Steering Committee composed of 12 attorneys. The Steering Committee compiled master list of issues and their priorities. One major issue that arose was whether or not groundwater uses and claims are subject to adjudication by the Court (Superior Court for Maricopa County). On September 9, 1988, the Court ruled that groundwater is subject to adjudication if it meets certain criteria or if the water source is for a claim based on federal law. Trial Judge Goodfarb's ruling stated that wells which pumped "appropriable" groundwater, or "subflow," would be subject to his jurisdiction in the adjudiction.
The court order of September 9, 1988 directed the ADWR to determine the boundary within which wells are pumping appropriable stream flow. The order stated that "...as to wells located in or close to that younger alluvium, the volume of stream depletion would reach 50% or more of the total volume pumped..." and the "...period of withdrawal is equivalent to 90 days of continuous pumping." This boundary marks the so-called "brightline" on either side of the stream within which wells would be classified as withdrawing appropriable subflow. The "brightline" represents the distance away from the stream bank where 50% of the volume of water pumped from a well would be expected to be derived from streamflow depletion after 90 days of continuous pumpage.
The 50%/90 day ruling generated an appeal which was ruled on by the Arizona Supreme Court on July 27, 1993. Based on the original legal assertion of the term "subflow" in the Maricopa County Municipal Water Conservation District No. One v. Southwest Cotton case in 1931, the Arizona Supreme Court reiterated its understanding of subflow as water that is "found within, or immediately adjacent to, the bed of the surface stream itself." After criticizing the time and volume elements of Judge Goodfarb's 50%/90 day rule, the Arizona Supreme Court emphasized that a well is pumping appropriable subflow if it pumps "water that is more closely associated with the stream than with the surrounding alluvium." Ultimately, the Court remanded the case to Judge Goodfarb to determine an appropriate set of criteria for defining subflow (Glennon and Maddock, 1992).
Glennon and Maddock (1994) point out the many hydrologic flaws in this ruling. First, it ignores time as a factor in distinguishing groundwater and surface waters, and consequently disavows any concept of hydrologic capture. Thus, it allows groundwater moving toward the river to be intercepted by pumping without compensation for the water lost at the original destination (i.e., the river). On the other hand, the Court also indicated that depletion occurs when production is "measurable," which must occur over some period of time. Second, it disregards the interconnectedness of groundwater wells, the aquifer, and the stream. The source of groundwater withdrawn from a well and the impact of that withdrawal on the regional groundwater and surface water system depend not only on the rate of pumping in that well, but on historical pumping rates by all wells in the vicinity. By suggesting that water moving away from the stream is not appropriable, the Court's ruling neglects the long term dynamic effect of pumping wells on the direction of groundwater flow. Third, the decision ignores seasonality, which is a critical factor in maintaining baseflows in the San Pedro River. A careful balance between pumping and seasonal recharge through precipitation could offset the detrimental effects of pumping on the river to some degree, but pumping near the river in periods of low flow (dry seasons) could deplete surface flows beyond recovery. Fourth, the ruling poses a scientific dilemma in defining the legal term "subflow," a word which, Glennon and Maddock (1994) contend, has no hydrologic meaning (Glennon and Maddock, 1992).
Judge Goodfarb assigned the task of defining subflow to the Arizona Department of Water Resources. Although highly critical of the Supreme Court's decision, the ADWR took on the task, and decided to interpret the ruling to mean "that subflow is the physical presence of water in a certain geographic location at a particular moment of time" (ADWR, 1993). As part of this interpretation, the ADWR decided to ignore the transmissivity and storage properties of the aquifer because evaluating these parameters involves the incorporation of time. Instead, static water levels from wells would be the basis for the ADWR's definition of subflow criteria. In July 1994, Judge Goodfarb filed his opinion on the issue of subflow. He developed a test for subflow and a test for the cone of depression of wells located outside the "subflow region." Abiding by the Supreme Court's constraints, Judge Goodfarb broadly defined subflow as the outer edge of the "saturated floodplain Holocene alluvium" (Maricopa Co. Super. Ct., 1994). This region in the San Pedro River is generally less than a mile wide and centered along the river. Judge Goodfarb also addressed the issue of wells located outside of the defined subflow region that might be pumping subflow. He ruled that wells outside the subflow area will be subject to the general adjudication to the extent that the water pumped comes from either the stream itself or the subflow area (Glennon and Maddock, 1992).
Another complication in the adjudication of water rights in the San Pedro Basin involves the implementation of federal water rights. Two issues are currently under consideration by the Arizona Supreme Court: 1) is nonappropriable groundwater subject to federal reserved rights? and 2) do federal reserved water rights holders enjoy greater protection from groundwater pumping than holders of state law rights? The four U.S. Supreme Court decisions listed earlier will play important roles in the solution of this issue.
In 1988, Congress passed the San Pedro Riparian National Conservation Area Act. This motion established the Conservation Area out of public domain lands managed by the BLM "in order to protect the riparian area and the aquatic, wildlife, archeological, paleontological, scientific, cultural, educational, and recreational resources of the public lands surrounding the San Pedro River in Cochise County, Arizona." The initial reservation comprised 56,000 acres and provided for the subsequent acquisition of additional parcels of land. The Act required the Secretary of the Interior to develop a long term management plan and it expressly reserved water rights.
Some confusion exists as to the method for quantifying the federally reserved water right for the SPRNCA. The U.S. Supreme Court is not bound by Arizona's definition of the hydrologic connection between surface water and groundwater if that definition fails to adequately protect federal interests. Although significant precedence exists for shifting federal reserved rights litigation into state courts (the McCarran Amendment, Colorado River Water Conservation District v. United States, and Arizona v. San Carlos Apache Tribe of Arizona), the federal government may attempt to change the trend. The federal government's desire for uniform federal rule governing federal interests in all states may provide incentive not to abide by Arizona's state water rights law. Another point of contention lies in deciding on whom the burden of proof to demonstrate the hydrologic connection between groundwater pumping and surface flows rests. The United States v. City and County of Denver (1982) case addressed administrative aspects of federal reserved rights. The case demonstrated the federal government's ability to draw on state appropriation law to preclude junior appropriators from interfering with the senior federal rights, while at the same time, provided that the federal government may insist on federal rules if it feels that state law is inadequate (Glennon and Maddock, 1992).
In the case of the San Pedro watershed, two independent federal interests may come into conflict. The Department of the Interior presides over federal reserved rights for the San Pedro National Conservation Area, and the Department of Defense (DOD) represents the interests of Fort Huachuca army post west of the San Pedro River. If the military post expands by the predicted 20 percent, the DOD might obtain rights to additional water supplies either under Arizona state law or under the federal reserved rights doctrine. How this expansion would affect the SPRNCA's reserved right is unclear. Fort Huachuca currently has the right to pump groundwater under Arizona's reasonable use doctrine. It may also have federal reserved rights to groundwater. This issue will be addressed by the Arizona Supreme Court in early 1995. If the Court rules that federal reserved rights extend to nonappropriable groundwater, then Fort Huachuca's federally reserved right has a priority date senior to that of the SPRNCA.
Although the circumstances surrounding the Gila River adjudication are exceedingly complex, two facts remain even if the Arizona Supreme Court adheres to its original ruling regarding the appropriation of subflow. First, the federal reserved rights doctrine will protect federal reservations in Arizona from harm by pumping of groundwater that is hydrologically connected to surface flows. Second, federal law has supremacy over state law rule (Glennon and Maddock, 1992).
The Upper San Pedro Basin contains one of the last vestiges of mature riparian habitat in the arid southwestern United States. This riparian corridor supports the richest and most diverse population of flora and fauna in the entire San Pedro River Basin, and it plays a vital role for migratory animals moving through Arizona. Sustenance of the urban and military populations in the Sierra Vista-Fort Huachuca area and irrigation water for agriculture along the San Pedro River constitute the two major cultural water uses in the Upper San Pedro Basin. The Sierra Vista-Fort Huachuca area population depends entirely on groundwater pumped from the regional aquifer west of the San Pedro River. While water from the San Pedro River is diverted by two irrigation ditches near the communities of St. David and Palominas, much of the water used for irrigation of cultivated lands in the San Pedro River floodplain comes from groundwater wells located in the floodplain aquifer.
Several numerical modeling studies of the Upper San Pedro Basin have shown that continued pumping in the Sierra Vista-Fort Huachuca area at its present rate or higher will most likely threaten surface flows of the San Pedro River in the future. This threat arises from the fact that pumping could induce increased infiltration of stream water to the aquifer by depleting aquifer storage. Vionnet and Maddock (1994) demonstrate that signs of surface water depletions in the Charleston are already visible through the examination of historical versus present losing and gaining stream reaches.
The validation and quantification of surface water and groundwater rights along in the San Pedro River Basin is currently under examination by the Maricopa County Superior Court as part of the general adjudication of the Gila River Basin. Competing interests for in the San Pedro River Basin pit federal rights holders against other federal rights holders and state rights holders. Questions of federal versus state jurisdiction regarding the determination of federal reserved rights and uncertainty over the legal and hydrologic definitions of "appropriable subflow" round out the rest of the debate. These extremely complex issues will drive the quantification of water rights in the Upper San Pedro Basin and will set important precedents for other watersheds in Arizona and other states where the conflicting goals of preservation of natural resources and urban development meet.