The unusually wet winter (with an assist from new Colorado River Drought Contingency Plan water reduction rules) has substantially reduced the near-term scare-the-crap-out-of-me risks on the Colorado River for the next few years, according to new Bureau of Reclamation modeling.
Modeling done in January showed significant risk – a nearly one in three chance – of Lake Mead dropping below elevation 1,025 by 2024, a level that would place the reservoir’s long term ability to make deliveries at risk. That has dropped to a one-in-30 chance, according to the new USBR modeling.
At Lake Powell, the risk of reaching elevation 3,525, a danger point beyond which power generation and the Upper Basin’s ability to meet Colorado River Compact delivery obligations are at risk, has dropped from a one in four chance by 2024 to a one in 25 chance. The chance of dropping below Powell’s minimum power pool – the point at which the reservoir is too low to generate electricity – has dropped from one in six to essentially zero.
Details of the modeling results, presented today to basin water managers, suggest the bulk of the risk reduction is the result of the wet winter, which has pumped up runoff and reservoir storage. But the new Drought Contingency Plan, under which water users in the Lower Colorado River Basin have agreed to leave water in Lake Mead if and when it drops below critical thresholds, also played a role.