Water Quantity

St. Croix's fresh water resources have never been abundant. Archaeological, historical, and geological evidence, however, indicates that fresh water resources were once more plentiful than they are today.

Rainwater collected from rooftop catchment systems and stored in cisterns is the most important source of water for St. Croix residents. Rainwater is used mainly by individual homeowners and to a lesser extent by commercial and industrial facilities. Desalinated sea water, produced by the VI Water & Power Authority (WAPA), supplies potable water to businesses and residences in urban and suburban areas, and is also used to supplement rain water cisterns during the dry season. According to the 2000 Census, 45% of St. Croix's residents use cistern water as their sole water source. In St. Croix, desalinated sea water and rainwater collected from rooftop catchment systems are considered to be surface water resources.

Groundwater in St. Croix provides only about 20 percent of the freshwater supply. St. Croix aquifers are small and have relatively poor yields and water quality. A majority of wells have saline concentrations greater than 1,000 milligrams per liter. Groundwater is drawn mainly by domestic and commercial users who are not connected to public supply systems. On St. Croix, the Virgin Islands Department of Public Works (DPW) uses ground water to supplement desalinated water in the public water supply system.

St. Croix's fresh water use is governed principally by the availability of water produced from desalinated water, intensity and duration of rainfall, and a limited amount of groundwater. Some streams are intermittent [LaGrange Gut, Caledonia Gut, Creque Gut, Bethlehem Gut], but most are ephemeral and flow only in the wet season or during intense rainstorms. Several industries and hotels use seawater to produce freshwater, and seawater also is used for fire fighting and for other non-consumptive uses.

Water Quality

St. Croix's most valuable natural resources are its pristine waters and its distinctive marine and wildlife habitats. St. Croix and its cays are surrounded by miles of the world’s most pristine bays and beaches, that in turn support some of the most beautiful coral reefs, mangroves, salt ponds and tropical sea grass beds. USVI waters and coastal shores are home to numerous species of fish, birds and other wildlife. Millions of tourists and residents alike enjoy year round swimming, renowned coastal waters and breath-taking beaches in St. Croix. 

However, protection of these unique features in the face of increasing population size and economic development has become increasingly difficult. As in many places around the world, St. Croix's waters are affected by development pressures from residents, industry and visitors, and related activities such as:

• Increased construction along coastlines.
• Boating activities.
• Increases in pollution sources such as vessel wastes.
• Sewage overflows and uncontrolled storm water runoff.

The Virgin Islands Department of Planning and Natural Resources (DPNR) is charged with protecting, maintaining and managing the natural and cultural resources of the Virgin Islands through proper coordination of economic and structural development in collaboration with other local, federal and non-government organizations, for the benefit of present and future generations so they will live safer, fuller lives in harmony with their environment and cultural heritage.

As part of its mission to protect and improve water quality, DPNR works with with local, regional and federal partners to increase public awareness of the immediate and long-term impacts of poor land use and development practices, and to promote implementation of a comprehensive watershed management strategy that incorporates the use of low-impact development practices and conservation of natural resources.