by Rachel Felver
April 17, 2018
With its rich natural resources, important role in history and access to culturally-rich communities, who wouldn’t want to call the Chesapeake Bay watershed home? Not many people, it turns out. Since 1950, the population of people in this region has more than doubled, and is on track to exceed 20 million inhabitants by 2030. That’s an increase of more than two million since the Chesapeake Bay Total Maximum Daily Load (Bay TMDL) was put into place in 2010.
Partially as a result of the growing human population, the land area devoted to agriculture is expected to continue its six-decade decline while the use of remaining farmland intensifies. Livestock, irrigation and double-cropping are all increasing. Agriculture animals like cows and chickens are estimated to increase by 13 percent from the period of 2013 to 2025. Together, human population growth, development and agricultural intensification may impact the amount of nutrient pollution flowing into local waterways and the Bay—by approximately four million additional pounds of nitrogen and 0.15 million pounds of phosphorus by 2025.
Each person and animal living in the Chesapeake Bay watershed affects the water around them, whether it’s done intentionally or not. Water is necessary for drinking, bathing and sustaining life. However, the consumption of natural resources can lead to air, water and land pollution. Land is cleared for agriculture and development, leading to more roads, parking lots, lawns and golf courses. Rainfall running off the land into storm drains, rivers and streams, picking up nutrient pollution and dislodging sediment along the way. Stormwater runoff is one of the fasting growing sources of pollution impacting the Chesapeake Bay.
To account for the potential increase in nutrient pollution, each of the Chesapeake Bay watershed jurisdictions—Delaware, the District of Columbia, Maryland, New York, Pennsylvania, Virginia and West Virginia—will develop their Phase III Watershed Implementation Plans (WIPs) based on potential future 2025 conditions.
By using these future projections, the six watershed states and the District of Columbia, will be able to plan consistently and efficiently to reduce their pollution loads due to growth. To be as accurate as possible, the 2025 growth projections will be updated every two years, using the most current data and zoning information. Local partners will have the opportunity to review the two year growth forecast when it is updated.
The Chesapeake Bay Program recently released updated modeling tools that use the latest science and real-time data (such as rainfall, river flow and monitored water quality conditions) to replicate conditions of the Chesapeake Bay watershed. One of the tools in this modeling suite, the Chesapeake Bay Land Change Model, forecasts potential future development patterns and their impacts to forests and farms. The Land Change Model can provide estimates of these impacts at state, county and small watershed scales. These data can then be entered into another tool in the modeling suite, the Chesapeake Assessment Scenario Tool, or CAST, which allows people to see the impacts from changes in land use on nutrient and sediment pollution in local waterways and the Chesapeake Bay.
Learn more about how you can take part in helping to lower the impacts of population growth on the watershed.