Simulations indicate that policy coordination is key to sustainability efforts


Preliminary analysis of the Computing for Sustainable Water data shows the importance of broad community-based coordination, so that environmental priorities can be achieved with a minimum of redundant effort. The project has also increased understanding of sustainability practices in other watershed areas.



During the volunteer effort for Computing for Sustainable Water, World Community Grid members returned over 19.1 million calculations. Now that the computing phase of the project is over, our research team has completed the preliminary analysis of these results, indicating the need for a coordinated approach to water quality management.

Our goal was to assess the impact of various programs intended to reduce the flow of nutrients (nitrogen and phosphorous) in the Chesapeake Bay Watershed in the United States. Excessive nutrient flow causes the development of algal blooms which eventually reduce the oxygen levels in the water, making it inhospitable for various life forms. When the level of dissolved oxygen in the water column gets close to 0, the area is termed ‘anoxic’. When the water column is not quite fully deprived of oxygen, the area is termed ‘hypoxic’. In the Chesapeake Bay, low oxygen causes a serious threat to a particular aquatic species - the Chesapeake blue crab - Callinectes sapidus. In other watersheds, comparable species are vulnerable to increased anoxia and hypoxia.

In the Chesapeake Bay Watershed, as in other areas throughout the world, various ’Best Management Practices’ (BMPs) are encouraged by watershed authorities to reduce the runoff of nutrients from agricultural fields as well as populated urban areas. BMPs include such programs as conservation tilling on farms, the planting and maintenance of riparian buffers along waterways, wetland restoration and urban nutrient management. There are typically subsidies available to encourage adoption of these BMPs. A question that intrigued the University of Virginia (UVa) team is whether these BMPs actually produce the reductions in nutrient flow that are expected.

Computing for Sustainable Water set about testing the effectiveness of 23 separate and popular BMPs to answer this question by relying on the help of World Community Grid volunteers. This was no easy task given the size of the Chesapeake Bay Watershed: 64,299 square miles (166,534 km^2) with a population of nearly 17 million people. A simulation model was built to replicate nutrient flow into the Bay in the presence of these BMPs. Each BMP was also modeled at three levels of effectiveness. The results, contained in a recently completed report that has not yet been made public, show that under the idealized condition that each BMP is implemented individually throughout the watershed, many have significant positive impact - that is, they offer real benefits for nutrient flow reduction. However, the more realistic condition of BMPs being used in various combinations showed, somewhat disappointingly, that the reductions in nutrient flow under these more realistic cases did not show significant reductions. The UVa team analyzed these results from a strictly objective perspective. Anecdotally, we believe that the uncoordinated and uneven application of BMPs throughout this vast area is, in fact, not achieving the desired impact. We have not analyzed all 19.1 million results yet but we intend to do so selectively over the next few months.

We do believe, as we speak with policy-makers and government authorities, that we can make a strong case that a more coordinated approach to nutrient management will prove more effective and will save taxpayers considerable expense as compared to implementing BMPs with little or no discernible impact.

As a result of this project, we have moved toward a deeper appreciation of the need to protect our watersheds and their surrounding ecosystems. We have been invited to discuss our project work in Brazil, Australia, the Pearl River Delta in China, Lake Michigan in the US, and now the US coastal areas along the Gulf of Mexico that suffer greatly from the effects of nutrient flow.

We have also moved toward using satellite data to produce land use and land cover maps to identify areas of particular concern. Our first application of these is along the Mississippi River Delta and the Houston/Galveston area of Texas in the US.

We sincerely appreciate the time and effort of the World Community Grid volunteers in making this project successful. We will post the availability of our report and any forthcoming publications.

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