Catawba Wateree Water Management Group 2015 Annual Report

Safe Yield Research Project

The Catawba-Wateree Water Management Group completed a tailored collaboration research project with the Water Research Foundation to define and enhance the safe yield of the Catawba-Wateree River Basin, a multi-use, multi-reservoir, water supply system. Projections indicate that regional water demands are likely to double in the next 50 years – placing an increased strain on water supply.

The raw water supply is provided by the Catawba-Wateree River – in particular, from eleven reservoirs that are operated by Duke Energy under a Federal Energy Regulatory Commission (FERC) license. For each enhancement strategy/scenario run, the percentage of time spent in each Low Inflow Protocol (LIP) stage was calculated to establish procedures for reductions in water use during periods of low inflow to the Catawba-Wateree. The LIP was developed on the basis that all parties with interests in water quantity will share the responsibility to establish priorities and to conserve the limited water supply.

The evaluation indicated that the LIP largely influences water yield values, and LIP influence was used as criteria for a more relevant comparison of the effectiveness of each strategy. Based on the water yield enhancement strategy modeling and evaluation results, the strategies deemed to be the most effective at increasing water yield were further evaluated.

A matrix of methodologies to assess financial, environmental, and public impacts was developed for each safe yield enhancement strategy. A screening-level analysis of environmental and permitting issues provided a good basis for comparing the potential environmental issues and permitting challenges of the selected safe yield enhancement strategies.

This report summarizes the modeling results for the water yield enhancement scenarios, including the effectiveness of each strategy, climate change impacts, LIP impacts, and next steps that include a Catawba-Wateree Water Supply Master Plan Update that is currently underway as required per the settlement agreement between North Carolina and South Carolina.

Water yield evaluation for Catawba-Wateree ranks among the most sophisticated approaches discovered in comparison systems review. This report was also highlighted in the April 2013 publication of the Water Research Foundation - Research On Tap.