With the growing populations of the cities in the South Western United States and increased agricultural needs, the demand for water placed on the Colorado River has be increasing dramatically. Pair this with reduced inflow to the Colorado River basin caused by the current eighteen year drought and the region is quickly coming to a breaking point where water demand is much greater than the supply. In their paper Shepherding Compact Security Water in the Upper Colorado River Basin, Lawrence MacDonnell and Anne Castle discuss the projected water shortage and a possible solution to the problem.
Starting in 2000 the Colorado River Basin has been experiencing a long term drought caused by increased temperatures from Global Warming. This drought has significantly reduced the amount of water flowing into Lake Powell from it’s tributaries. The long term drought has forced the increased use of water storages in Lake Mead and Lake Powell significantly lowering their levels. The lower levels of these water storages increases concerns of potential water shortages in the states of the Lower Basin and threatens curtailment of water resources in the states of the Upper Basin. The place of demarcation between the Upper and Lower Basin is at Lee’s Ferry along the Colorado River. MacDonnell and Castle (2018) state that according to the “Colorado River Compact of 1922 the Upper Basin states must not cause the depletion of Colorado River flows below that necessary to ensure that 75 million acre feet of water pass Lee’s Ferry during any consecutive ten year period” (p. 28).
In order to maintain the 75 million acre feet required and prevent reaching critical water storage levels the Upper Basin states have developed the System Conservation Pilot Program (SCCP). This program is funded by the Beureau of Reclemation and other municipal water utilities and provides monetary compensation for voluntary water conservation and the benefit of the Colorado River (p. 28). This voluntary conservation is in order to prevent mandatory curtailment of existing water uses if the ten year average falls below the 75 million acre feet. The main holdback from water right users is that they are concerned that by not using their water allotment there is the possibility that they will end up with a diminished water right. An example of this would be if a current water right holder voluntarily cut their water usage by half for 5 years. In this 5 year period other water right users increased their usage or weather conditions had drastically become worse. After the 5 years period the volunteer needed to return to their full water usage but might not be allowed to due to new legislation of simply the lack of water available at Lee’s Ferry due to Lake Powell being dry (pp. 28-29).
Another issue with voluntarily reduction of usage by water rights holders is that downstream users could see this extra water as available to them and diverted for their use. In order to prevent usage of water in this manner the water could be shepherded to the water storage facilities. The term shepherding refers to intentionally moving water from the place of customary use to a new location. The process of shepherding would be costly as a system of pipelines, aqueducts and other infrastructure would need to be created and maintained. There would also be legislation that would need to be created and ratified on how this water would be transported across state lines. If the length of time spent creating and approving of the Colorado River Compact of 1922 is any guideline for how long this process will take, the legal aspect will take far longer than the actual construction of a new shepherding system. The intent of this shepherding system is to allow the states of the Upper Basin to create a “savings bank” of water in Lake Powell. The amount that was saved in this manner of savings could be calculated and at times of severe extended drought each states savings could be used for release to achieve the ten year average flow rate at Lee’s Ferry (p.29).
In an attempt to avoid mandatory curtailments of existing water usage Lawrence MacDonnell and Anne Castle discuss in their paper “Shepherding Compact Security Water in the Upper Colorado River Basin” a possible solution to deal with the current long term drought. The solution of voluntary water conservation by current water right holders will take some guarantee that their current water right will be diminished for future use by participating in the SCPP. In order to prevent downstream water right holders from being diverted by use above the volume of their water right a shepherding infrastructure system might need to be created to bring this water directly to the storage areas. Water in the South Western United States will continue to be a limited resource for the foreseeable future. In order to deal with this scarcity the states of the Colorado River Basin will need to continue to work together in order to come up with solutions to this problem.
MacDonnell L., Castle A., (2018) Shepherding Compact security water inthe Upper Colorado River Basin.Colorado Water,https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3166287