In the late 1970s, scientific and estuarine research on the Chesapeake Bay pinpointed three areas causing water quality deterioration that required immediate attention: nutrient over-enrichment, dwindling underwater Bay grasses, and toxic pollution. Beginning in 1980, the legislatures of Virginia, Maryland and Pennsylvania established the Chesapeake Bay Commission (CBC) to begin to address these problems and coordinate interstate planning and programs from a legislative perspective.
These actions led to the historic Chesapeake Bay Agreement of 1983, which called on all local, state and federal agencies with jurisdictions in the Chesapeake Bay watershed to focus their existing pollution control programs on reducing nutrient loads to the Bay. The Agreement proposed a series of objectives and priority commitments to establish a policy and institutional framework for cooperative efforts to restore the Chesapeake Bay.
The parties committed to specific actions to achieve the objectives, and decided to review the implementation of such actions annually with additional commitments developed as needed. Stakeholders set a major goal to reduce the nutrients (N, P) entering the Bay by 40% by year 2000.
Basin` wide integrated modeling activities assisted in the evaluation and monitoring of water quality changes. As such, water quality data management, analysis, and modeling became a cornerstone in future stakeholder involvement to access data, review alternative water quality management options, and provide input to the decision making process.
The use of modeling tools in the case of the Chesapeake Bay was effective in implementing the actions and monitoring the goals set by the CBP partners. It provided decision makers with quantitative information that has assisted the restoration efforts of the Bay. The tools supplied the basis for policy makers to reach an agreement and to commit resources to work towards a common goal on an otherwise highly untenable consensus.
Model results must be efficiently summarized in a clear and timely manner. Independent experts in the field must frequently review the modeling strategy and results.
Informing stakeholders on the progress of the modelling effort enhances support for restoration efforts throughout the watershed.
A public version of the calibrated and verified model should be made available with online or easy access. Models are extremely useful to assist in integrated water quality management and ecosystem protection.
Importance of case for IWRM
The case shows how the use of modelling can be a cost-effective tool in helping to implement watershed restoration actions and monitor goals set by stakeholders.
Computer simulation of a large number of scenarios provides a realistic look at the combined impact of a broad array of land use activities and policies, thereby facilitating IWRM decision-making.
This case references the public domain watershed model currently used in different parts of the world for IWRM, and highlights its usefulness and availability to other managers.
Photo credit: Kevin Galens