Sustainable water management in the Ohio River Basin taking ecosystem services into consideration

Background/Question/Methods

The Ohio River (OR) is an important river system in North America. It has many different functions for use by humans and wildlife. Water quality of the Ohio River main stem is for 50% impaired. The impairment originates from point sources located on the shores of the OR, from non-point sources and from inflows of tributaries. The river also carries a high load of nitrogen (N) and contributes significantly to the anoxia in the Gulf of Mexico. Water in the OR is expected to benefit from sustainable water management. The river flows within a large watershed, composed by multiple subwatersheds with a variety of ecosystems. Ecosystems may provide several ecosystem services (ES) important for sustainable water management. This study aims at addressing the following questions: (1) Do increased ES have the potential to contribute to sustainable watershed management; (2) To which extent; and (3) At which cost. The project follows a 3-phased approach. In the first phase, ES in the OR basin are mapped in current and past times (spatial scale: 8-HUC, if available,12-HUC), and a sustainable integrated watershed management/restoration agenda is formulated. ES are mapped as follows: for past times according to soil and land cover classes; for current times in compliance with the Millenium Assessment, augmented with ES accepted within the EPA Ecosystem Services Research Program. Mapping is focused on rivers, -connected reservoirs, and the surrounding landscapes. ES values are assigned based on literature. In the second phase, scenarios will be explored to identify potential benefits of changes in ES, brought about by restoration measures and/or changes in management, by modeling hydrology and water quality (WQ2) in headwaters and downstream reaches of one OR subwatershed. In the third phase, the outcomes of alternative WQ2 scenarios will be compared, cost-benefit analysis of a subset conducted, best alternatives selected and  optimized, and follow-up by policy planners recommended.  

Results/Conclusions

The project is currently in its’ first phase. Early results of this study and others (e.g., National Fish Habitat Action Plan 2010), suggest that the potential for ES increase, and N loading decrease,  through restoration and/or management changes is greatest in the Eastern part of the OR basin where agriculture is intensifying. Details are needed to identify the subwatersheds with greatest potential.