Bay Watershed Population

As of 2022, 18,627,666 people were estimated to live in the Bay watershed, slightly up from 18,600,310 23 in 2021. The long-term trend is a large increase; from 1950 through 2022, the Bay watershed’s population increased from 8,380,319 to 18,627,666.

The way humans use the land has a dramatic impact on the Bay and local waterways. The decline in the health of the Chesapeake Bay is correlated to the rise in population in the watershed from 1950 through the 1980s. Experts predict that the watershed’s population will increase up to nearly 22 million by the year 2050, with related loss of natural areas and increases in urban development. While the rate of growth is expected to decline steadily through 2050, absolute growth is expected to continue to exceed 1 million per decade. This increase in human population and its effects are expected to pose new challenges for the land use-related outcomes within the Chesapeake Bay Watershed Agreement.

Data Costs

Our partners have invested more than $3 million in land cover data. While the cost of future data development efforts may fall with improvements in instruments, imagery and classification techniques, these costs could still be considerable.

Monitoring Costs

The sustainability of long-term monitoring is a question of political will. Fiscal constraints could impact the temporal and spatial scale at which we assess land cover change. Monitoring every two to three years will require more funding, but monitoring every four to five years may not provide resource managers or elected officials with the timely information needed to support new policies.

Metrics Development

Addressing this outcome will require metrics that account for the conversion of forests, farmland and wetlands and for changes in impervious cover. Each type of conversion presents unique monitoring challenges. Wetlands, for instance, cannot be accurately mapped with only the leaf-off and leaf-on aerial imagery typically collected by state and federal agencies. While techniques that use high-resolution data to assess landscape change with the precision needed to inform county-level decisions have advanced, they are not sufficiently established to distinguish between persistent and ephemeral changes in land cover.

Impact Methodologies

Techniques to quantify the social and environmental impacts of land conversion must be explored and developed. Examining impacts to water quality, for instance, may require different approaches for nitrogen, phosphorus and sediment. Examining impacts to wildlife habitat may require regional habitat assessments for keystone species, species guilds or particular species of concern. Examining social and economic impacts will perhaps be the most challenging. Land conversions (other than those caused by extreme weather events) are often motivated by private and public interests, and their impacts are often characterized as overwhelmingly positive by the time they occur. Identifying negative impacts to the environment or to under-represented or at-risk communities challenges the status quo and risks becoming politicized.