Dry spring offers hope for this summer; now’s the time to think about 2007
Later this month, the Bay Program will issue its second annual “Summer Forecast,” an attempt to predict key ecological conditions in the Chesapeake in the coming months. Using spring stream-flow measures, a rich 20-year monitoring program data set, and some sophisticated computer simulations, we will report on expected dissolved oxygen conditions, the potential for harmful algal blooms, and the likelihood that underwater Bay grasses will continue to expand.
As I write this, analysts are still reviewing their numbers and refining their calculations. But given the record low spring flow of freshwater in the streams and rivers that feed the Chesapeake, I expect that they will end up with a forecast that predicts slightly improved ecological conditions this summer. The relationship between spring river flow and the summertime health of the Bay is a strong one.
Only about one-quarter of the excess nutrient pollution enters the Bay via wastewater treatment plants. All of the rest, including the air pollution that settles on the water and landscape of the entire basin, comes off the land in the form of surface runoff or through the labyrinth of underground water systems that eventually seep into local streams.
The record low stream flows this spring mean that the nutrient pollution on the landscape and in groundwater has had less opportunity to flush into the Bay than the last three years.
Fewer nutrients in the system translate into fewer algal blooms. Decomposition of these excess algae robs the water column of essential dissolved oxygen and leads to the “dead zones” that have become an annual summertime scourge in the deeper waters of the Chesapeake Bay.
The sustained drought conditions that hit the mid-Atlantic region in the late 1990s and into 2002 resulted in a healthy resurgence of underwater Bay grasses and a remarkably good year for dissolved oxygen levels by the end of that period.
But that stretch of improving water quality came to an abrupt end in 2003, when near-record wet weather washed massive amounts of pent-up pollution into the Bay. That year saw a 30 percent drop in Bay grasses and a huge increase in the extent of the dreaded dead zone.
In 2002, water monitoring data and computer simulations suggested that the total loads of excess nutrients into the Bay were very near our long-term goals. The system was responding positively to that decreased stress, telling natural resource managers that our focus on nutrient reductions was exactly right.
Ironically, the string of dry weather that had farmers worried had also given us a glimpse of how the Bay would respond to the effective implementation of pollution reduction strategies.
Weather systems fluctuate, of course. We aren’t going to eliminate nonpoint source pollution, so wet years are always going to bring more nutrients and sediments into the Bay than dry years.
What we can and must achieve, however, is a dramatic decline in those pollution loads. When the inevitable wet weather arrives, we need to make sure that the added stress to the ecosystem is not so great that dead zones flourish and underwater Bay grasses fail to grow.
Even while allowing for natural annual variations, our goal needs to be steadily improving ecological health forecasts. And the way to do that is to accelerate pollution reduction activities.
To accelerate the pace of water quality and aquatic habitat restoration, Bay Program partners are taking a number of steps to make the most cost-effective use of available regulatory, incentive and voluntary tools. Core Clean Water Act programs provide a foundation of water pollution control and wetlands protection that is critical to protecting and restoring Chesapeake Bay tidal waters.
Clean Air Act regulations controlling the emissions of nitrogen compounds also contribute substantially to the Bay’s restoration. New state air pollution control efforts that go beyond national requirements will provide an additional boost.
All of the states in the watershed are setting stronger nutrient limits for wastewater facilities under the Chesapeake Bay permitting approach.
New permit requirements are also being put in place for factory farms.
To curb urban/suburban stormwater loads and damage to the watershed’s carrying capacity from rapidly increasing impervious surface acreage. Bay Program partners need to strengthen the implementation of municipal storm sewer and construction permit requirements as well.
Wastewater Treatment: We have already taken steps to increase the cost-effectiveness of nutrient controls in wastewater treatment, by supporting demonstrations of biological nitrogen removal and justifying the use of annual load limits in permits.
Virginia and Pennsylvania are accelerating nutrient reduction requirements in this sector by designing and implementing market-driven watershed permits and nutrient trading.
Several states, including Maryland, Virginia and Pennsylvania are providing special financial assistance in the form of grants and low-interest loans to make these upgrades more affordable.
Agriculture: The cleanup plans called tributary strategies define specific approaches for reducing nutrient and sediment loads from agricultural operations, the largest category of sources. They emphasize agricultural Best Management Practices such as nutrient management, low/no-till cultivation, cover crops and forest buffer restoration, which are among the most cost-effective of all measures for controlling nutrient-sediment pollution loads. We need to further integrate tributary strategy implementation with Farm Bill programs.
The Bay Program’s animal manure management strategy emphasizes innovative measures such as animal feed adjustment, and encourages markets for manure-based products, such as soil amendments on federal and state lands.
Urban/Suburban Lands: In 2004, the Blue Ribbon Finance Panel established by the Chesapeake Executive Council stressed that stormwater pollution prevention, coupled with the preservation of riparian forest buffers and wetlands, was by far the most cost- effective approach to controlling pollution from urban/suburban development.
The Executive Council agreed, and now the partners need to strengthen these efforts.
The goal is to establish and implement a basinwide consensus on principles and standards for regulating new development and redevelopment, linking federal, state and local programs and emphasizing “low impact development,” preservation of natural streamside buffers, increased urban tree canopy and wetlands restoration, with watershed approaches including trading and restoration banking.
A pair of federal grants programs, one aimed at local projects and the other for larger-scale efforts, will be in full operation for the first time this year.
The Small Watershed Grants program, which has been in existence since 1999, has a terrific track record of supporting local efforts to cut pollution and restore habitat.
The new Targeted Watershed Grants program shows great promise. Funded by grants of up to $1 million, these large-scale projects will demonstrate the nutrient reduction effectiveness of a number of different BMPs. The focus is on nonpoint source pollution, and early predictions are that the projects will prevent millions of pounds of nutrients from entering the Bay.
The 2006 summer ecological forecast from the Bay Program will be out soon. Our attention, though, has already turned to next year. The next 12 months will be key in determining the forecast for the summer of 2007.
Now is the time to get to work to assure progress that is more than a mere reflection of the weather report.
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