Port Royal Sound FoundationPRSound Science

PRS Watershed

AboutBoundaries
Water LevelsWeather
A Living Watershed

Water Quality

AboutMonitoring Locations

Land Cover

AboutForty Years of Change

Marsh Dynamics

AboutWetlands over Time

Biodiversity

AboutBiodiversity IndicatorsOyster Reefs

Resilience

AboutWatershed DevelopmentStrategy Explorer
Resilience

Watershed Development

Development pressure · annual rate of change

Mapped land conversion slowed after 2008, then increased again.

Annual NLCD identifies acres newly classified as developed from one year to the next. The mortgage-rate line provides national housing-market context, but the two series do not move closely enough to establish a direct relationship. Local conversion also reflects demand, land availability, infrastructure, and policy.

Annual newly developed acres and U.S. 30-year mortgage rate · 1986–2024

Bars: acres newly classified as developed each year (left axis). Line: U.S. 30-year fixed mortgage rate, annual average (right axis).

Peak 2006: 2,730 acres in a single year. 1.0k acres per year on average from 2015 through 2024.

Three periods in the mapped record

Highest-conversion period · 1998–2007

The series records 18,272 acres newly classified as developed, averaging 1,827 acres per year. This is the highest total for any 10-year window in the series.

Sharp slowdown · 2008–2014

The annual average fell to 460 acres, with mapped conversion below 500 acres in 5 years during this period.

Renewed conversion · 2015–2024

Mapped conversion averaged 1,032 acres per year: more than twice the 2008–2014 average, while remaining below the 1998–2007 average.

Share of subwatershed classified as developed · 2024

  • Broad Creek
    62.3%
  • Battery Creek
    40.3%
  • Colleton River
    34.5%
  • Upper Beaufort River-Atlantic Intracoastal Waterway
    30.7%
  • Calibogue Sound
    27.4%
  • May River
    25.3%
  • House Fork
    23.0%
  • Upper New River-Atlantic Intracoastal Waterway
    22.3%

Top eight of the 40 official subwatersheds. Percentages use each subwatershed’s total mapped area, including open water. This is a 2024 snapshot, not change since 1985.

Development map · % developed by HUC12 subwatershed (2024)

Color intensity shows the share of each subwatershed classified as developed in 2024, using its total mapped area including open water. The dark overlay shows land classified as developed in 2024 but not in 1985.

From pressure to action · GIFT strategies

From watershed data to parcel-level action.

The Green Infrastructure Framework Tool (GIFT) pairs four decades of land-cover change with parcel-level indicators of flood risk, water quality, habitat, heat, and development. The whole-watershed strategy mix below is a starting point; open the Strategy Explorer to compare subwatersheds and select parcels for recommended Preserve, Enhance, Mitigate, or Retrofit strategies.

Open the Strategy Explorer →