Spate irrigation, a floodwater harvesting and management system, has for the past 70 centuries provided a livelihood for about 13 million resource-poor people in some 20 countries. Despite being the oldest, the system still remains the least studied and the least understood. It is only in the past two decades that the system has been subject to some modernization interventions, much of which focused on improving floodwater diversion efficiency.

In recent decades, increasing conflicts have occurred between different water users because of issues related to water resource allocation. To better allocate water resources, this study adopts the latest water rights trading model instead of the traditional water resources allocation model and combines it with a two-stage interval-parameter stochastic programming model (TISP). The combined model was applied to the Sanjiang Plain with multi-area, multi-source, and multi-water users, and the optimized promised water availability for every user in the area was obtained.

The 2004 Arizona Water Settlements Act (AWSA 2004) when implemented will allocate to two Native American tribes, the Gila River Indian Community (GRIC) and the Tohono O'odham Nation (TON) almost ten percent of Arizona's total developed water supply, which is 7.04 million acre-feet a year. The successful passage of AWSA, given the scale of the water rights settlement and competing uses for finite water supplies, is the topic of this paper.

Augustin Cournot's original concept of “complementary oligopoly” has recently had a rebirth of interest after being relabeled “the tragedy of the anticommons” and finding fresh applications in the legal and economics literatures. The tragedy of the anticommons (the mirror image of the more well-known tragedy of the commons) occurs when too many rights holders to a good lead to sub-optimal usage. Inefficient outcomes are only overcome when rights holders are reduced or consolidated.