11:45 AM - 12:00 PM
[AHW19-10] Is Wastewater Reuse a Sustainable Solution to Meet Increasing Water Demands Under Climate Change? A Case Study based on Vectorized Hydro-modeling in Red River Basin
Keywords:hydrologic modeling, wastewater reuse, climate change
Wastewater reuse is potentially a viable option for mitigating the impacts of climate change and increased water demands on available water supplies. However, water reuse must be implemented in such to minimize the negative impacts on streams, ecosystems, and downstream water users that previously received this wastewater effluent. This study develops a comprehensive assessment of the potential environmental impacts and societal benefits of wastewater reuse in the Red River basin. A coupled riverflow modeling framework (CREST-SWAT) is developed in attempts to integrate water quality and quantity simulation to assist water management at large spatial scales. A historical (1990 to 2020) simulation is first evaluated against observed streamflow to ensure the model’s capability in capturing the hydro-climatology in the study watershed. Ensemble future simulations are then assessed regarding the change in ‘time below the environmental flow’ (Qenv, defined as 30th percentile of historical streamflow) under various emission scenarios and wastewater reduction rates. The results show that climate change’s dominant effects in causing longer time below Qenv than in the historical simulation for all test cases. However, a close examination of individual reaches/catchments shows the room to balance the impacts of climate change and water supplies locally. Based on the allocated water rights, the benefit from wastewater recycling is further categorized in terms of usage, e.g., public water, irrigation, power, etc. Overall, the study demonstrates utility of the integrated modeling framework in developing water management plans facing the changing climate.