Reducing the discharge of pollutants to our waterways does result in a revitalization of the associated ecosystems. That progress can seem slow; however, since the pollutants were released over several decades the cleanup will likely require a similar timeframe. Implementation of the Chesapeake Bay TMDL will address the release of nitrates, phosphorous and sediment to the Bay from both point and nonpoint sources. The following article discusses the Lynnhaven River and notes that visible progress can be made in less than a decade.
Compliance with the Bay TMDL will present difficult choices and potential for increased expenditures. When compliance results in visible progress at the scale of the Bay and elsewhere throughout Virginia, similar to that seen locally on the Lynnhaven River, then the cost/benefit will become more palatable. The complexity of the Bay ecosystem and the uncertainties associated with the model used to evaluate the health of the Bay and the progress of its cleanup however may not translate quickly into such visible improvements that the Lynnhaven River has seen over nearly a decade, Without continued, visible improvement to the Bay and other waterways, the challenges will remain difficult.
http://hamptonroads.com/2012/01/lynnhavens-friends-celebrate-progress-dig-do-more