An analysis of the allocation of Yakima River water in terms of sustainability and economic efficiency.

Decades of agricultural growth has led to the over appropriation of Yakima water and the ecological integrity of the Basin has been compromised. We evaluate the impact of current water allocation on the natural flow regime of the Yakima River using the Indicators of Hydrologic Alteration/Range of Variability Analysis and by quantifying indicators of ecosurplus and ecodeficit. We analyze the sustainability of the current water allocation scheme based on a range of sustainability criteria, from weak to strong to environmentally sustainable. Economic efficiency is assessed by describing the current allocation framework and suggesting ways to make it more efficient. Our IHA/RVA analysis suggests that the allocation of water in the Yakima River has resulted in a highly altered flow regime. Ecodeficit is far in excess of ecosurplus. We conclude that this allocation scheme is weakly sustainable, if sustainable at all, in its current framework. The allocation of water is also not economically efficient and we suggest that a reallocation of water rights may be necessary in order to achieve this objective. The creation of water markets to stimulate voluntary water rights transactions is the best way to approach economic efficiency. The first step would be to extend beneficial use requirements to include instream flows, which would essentially allow individuals to convert offstream rights into instream rights. The Washington trust water rights program was implemented as a means of creating a water market, which has contributed to the protection of instream flows, however more needs to be done to create an ideal water rights market so that rights migrate to higher valued uses, many of which are met instream. However, water markets will likely not solve the Yakima's water allocation problems alone; some degree of regulation may still be necessary.