Mechanism for Fair Allocation of Surface Water under the Riparian Doctrine

Abstract

The common-law Riparian Doctrine, the legal basis for water allocation in the eastern United States, restricts qualified users along a shared waterway to reasonable withdrawals. Recent water shortages and droughts have highlighted the need for more specific withdrawal restrictions, and laws have been passed. What is still missing, however, is a water allocation mechanism that is consistent with the Riparian Doctrine and one that can accommodate downstream demands in quantifying the withdrawal limits and reservoir release rules. The present study proposes one such mechanism, called proportionally fair (ProFair) allocation, which fulfills this need. It is realized by a so-called bottleneck algorithm (BA), which allots water proportionally in a large stream network through a series of successive steps. It is discovered that the ProFair allocation can be simulated by a log-linear programming (LLP) model. The equivalence of the LLP model and the BA is proved. The Upper Neuse River watershed in North Carolina serves as an example to demonstrate the effectiveness of the ProFair mechanism.