Improved regional water management utilizing climate forecasts: An interbasin transfer model with a risk management framework

Abstract

Regional water supply systems undergo surplus and deficit conditions due to differences in inflow characteristics as well as due to their seasonal demand patterns. This study proposes a framework for regional water management by proposing an interbasin transfer (IBT) model that uses climate-informationbased inflow forecast for minimizing the deviations from the end-of-season target storage across the participating pools. Using the ensemble streamflow forecast, the IBT water allocation model was applied for two reservoir systems in the North Carolina Triangle Area. Results show that interbasin transfers initiated by the ensemble streamflow forecast could potentially improve the overall water supply reliability as the demand continues to grow in the Triangle Area. To further understand the utility of climate forecasts in facilitating IBT under different spatial correlation structures between inflows and between the initial storages of the two systems, a synthetic experiment was designed to evaluate the framework under inflow forecast having different skills. Findings from the synthetic study can be summarized as follows: (a) inflow forecasts combined with the proposed IBT optimization model provide improved allocation in comparison to the allocations obtained under the no-transfer scenario as well as under transfers obtained with climatology; (b) spatial correlations between inflows and between initial storages among participating reservoirs could also influence the potential benefits that could be achieved through IBT; (c) IBT is particularly beneficial for systems that experience low correlations between inflows or between initial storages or on both attributes of the regional water supply system. Thus, if both infrastructure and permitting structures exist for promoting interbasin transfers, season-ahead inflow forecasts could provide added benefits in forecasting surplus/deficit conditions among the participating pools in the regional water supply system.

Complex relationship between seasonal streamflow forecast skill and value in reservoir operations

“…An emerging field of research has begun to demonstrate the value of seasonal streamflow forecasts when applied to real-world water management problems, such as determining the appropriate water release from a reservoir -the focus of the present study. Water release decisions can be improved with seasonal forecasts across a variety of reservoir types, including hydropower dams (Kim and Palmer, 1997;Faber and Stedinger, 2001;Hamlet et al, 2002;Alemu et al, 2010;Block, 2011), water supply reservoirs (Anghileri et al, 2016;Zhao and Zhao, 2014;Li et al, 2014) and reservoir systems operated for multiple competing objectives (Graham and Georgakakos, 2010;Georgakakos et al, 2012). Operators considering whether to adopt a forecast-informed operating scheme should be encouraged by these outcomes.…”

Making the most of data: An information selection and assessment framework to improve water systems operations

“…In the literature, numerous studies have focused on these questions by incorporating basic hydrologic information, selected on the basis of operators' experience, in a dynamic programming framework adopted for the design of water reservoirs operations. Common choices have been the observations of previous period's inflows [e.g., Bras et al ., ; Tejada‐Guibert et al ., ], simplified models of other hydrologic variables [e.g., Côté et al ., ; Desreumaux et al ., ], or streamflow forecasts [e.g., Stedinger et al ., ; Karamouz and Vasiliadis , ; Kim and Palmer , ; Faber and Stedinger , ; Maurer and Lettenmaier , ; Voisin et al ., ; Shukla et al ., ; Oludhe et al ., ; Li et al ., ; Zhao et al ., ]. As for the latter, the use of reliable inflow forecasts is beneficial under most situations.…”

Inventory of Interbasin Transfers in the United States

“…Management of regional water resources with IBTs, taking into account climate forecasts, is another aspect that has been explored (Li et al ., ). The distribution of water from regional transfers has also been tracked utilizing stable isotope comparisons in the water supply, to identify if nonlocal water sources are present at the end use location (Good et al ., ).…”