Browsing by Subject "prior appropriation"

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Open Access
Benefits, Costs, and Distributional Impacts of a Groundwater Trading Program in the Diamond Valley, Nevada
(2016-10-17) Zeff, Harrison; Characklis, Greg; Jeuland, Marc; Kaczan, David; Murray, Brian; Locklier, Katie
In Nevada’s Diamond Valley, unsustainable groundwater pumping has decreased the aquifer’s water level, raising irrigators’ pumping costs and threatening the viability of existing wells and springs. Continued extraction in excess of natural recharge will trigger a legally required curtailment of water rights in the valley, which was recently declared a critical management area (CMA). The extent of rights curtailment is not mandated, but it could be as high as 64%, the amount required to reach the estimated natural recharge rate. The default policy for curtailment of water rights will occur according to the principle of prior appropriation, whereby rights are revoked in reverse order of their date of issuance. Rights granted most recently will be canceled first, and the revocation will proceed in order of increasing seniority until the government’s desired level of total water extraction is reached. Nevada law requires this intervention to occur within 10 years of the CMA declaration. By law, irrigators and other stakeholders can propose alternative policies for reducing groundwater over-extraction. Because sudden rights curtailment could have detrimental economic impacts, such policies are under discussion. This report analyzes the economic outcomes of sudden and alternative curtailment policies. Using a hydro-economic model tailored to conditions in the region to examine alternative extraction scenarios, the analysis finds that, with no action, the depth to the water table will exceed 200 feet by 2045; with policy action, aquifer levels can be stabilized at 170–180 feet and at higher depths with more gradual curtailment. Across all policy scenarios, net agricultural profit is lowest under the default curtailment policy, and it increases with more gradual curtailment. Under curtailment, allowing parties to trade rights to extract water modestly increases economic benefits relative to no-trade alternatives.
Open Access
Minimization of Third-Party Injury in Multi-Party Water Right Transfers in Colorado
(2017-04-28) Hamilton, Andrew L
In the western United States, prior appropriation is the dominant form of water rights. In times of scarcity, the most senior water rights are given priority. Water right transfers can increase economic eﬃciency by moving water toward higher value uses, but the parties involved must prove that transfers do not reduce water availability for third-party users. In this study, prior appropriation and water right transfers were studied using the Upper Gunnison River Basin in Colorado as a test case. Streams and diversion structures were combined into a simplified network object in the R language. A ﬂow allocation model was then developed to solve for the set of withdrawals and streamﬂows consistent with mass balance constraints and prior appropriation. The ﬁrst objective of this work was to explore the drivers on water availability under prior appropriation. Speciﬁcally considered were the eﬀects of spatial and temporal hydrologic variability, as well as the set of upstream and downstream priorities, on water availability for a given water right holder. Additionally, the eﬀects of these drivers on water right transfers and third-party injuries were explored. Next, a number of case studies were developed which showcase strategies for using carefully constructed water right transfers for various ends. Multi-party overlapping water right transfers were considered as a solution to the problem of third-party injury. Multi-party water right transfers were also suggested as a means to reduce transaction costs in water right transfers. Symmetric, bilateral water right transfers were considered as a way of transferring hydrologic risk. Lastly, downstream water right transfers were suggested as a strategy for increasing instream ﬂows in vulnerable reaches. In addition to these heuristic case studies, a web-based tool was developed which allows users to explore water rights within the Upper Gunnison River Basin and test the eﬀects of multi-party transfers on third-parties and instream ﬂows. I hope that this tool will be useful for water managers, regulators, and educators who would like to develop a better understanding of prior appropriation rules and the eﬀects of water right transfers.