The USGS Caribbean-Florida Water Science Center Strategic Science Plan 2017-2027: A blueprint for USGS contributions to water resource science in Florida, Puerto Rico, and the US Virgin Islands
Stamm, J.F., Rodríguez, J.M., Sifuentes, D.F., Sumner, D.M., and Grimsley, K.J. with contributions from Bogeajis, N., Torres-González, S., McBride, W.S., Parks, J., and Decker, J.
The mission of the U.S. Geological Survey (USGS) is to serve the Nation by providing scientific information to describe and understand the Earth, minimize losses from natural disasters, manage resources, and enhance and protect our quality of life. The strategic plan of the USGS outlines seven Mission Areas, each of which address issues that affect the well-being of the Nation and the world:
- Core Science Systems,
- Climate and Land Use Change,
- Energy and Minerals,
- Environmental Health,
- Natural Hazards,
Mission Areas naturally overlap, such as the Water and Natural Hazards Mission Areas response to flood events and hurricanes. The overlap of Mission Areas is further realized through the Core Science Mission Area which transcends and enables collaboration between Mission Areas.
Each Mission Area has a documented science strategy. The Water Mission Area Science Strategy is based on four guiding principles related to water resources and the water cycle (fig. 1): observe, understand, predict, and deliver. The guiding principles were used to identify five goals of the Water Mission Area, which can be summarized as:
- Providing society the information it needs regarding the amount and quality of water in all components of the water cycle at high temporal and spatial resolution, nationwide;
- Advancing our understanding of processes that determine water availability;
- Predicting changes in the quantity and quality of water resources in response to changing climate, population, land use, and management scenarios;
- Anticipating and responding to water-related emergencies and conflict;
- Delivering timely hydrologic data, analyses, and decision support tools seamlessly across the Nation to support water-resource decisions.
Figure 1. The water cycle. Adapted from Evenson and others (2013, Figure 20).
The goals of the USGS are guided by Fundamental Science Practices that are brought to bear on all projects and programs. The goal of Fundamental Science Practices is to provide unbiased, objective, and impartial scientific information to audiences and cooperators; Bureau Fundamental Science Practices were articulated in 2011 in USGS Circular 1367. Fundamental Science Practices encompasses all aspect of research, including data collection, experimentation, analysis, writing analysis, writing results, peer review, management review, Bureau approval, and publication of products.
Four programmatic areas within the Water Mission Area have been designated to address and achieve these goals:
- Water Availability and Use Science Program (WAUSP),
- Groundwater and Streamflow Information Program (GWSIP),
- National Water Quality Program (NWQP),
- Water Resources Research Institutes Program (WRRI).
Guiding principles, goals, and programmatic areas are locally realized at Water Science Centers. The Caribbean-Florida Water Science Center (CFWSC) serves the needs of water resource managers, government agencies, and other customers within Florida, Puerto Rico, and the U.S. Virgin Islands, but is not limited to this region (fig. 2).
Figure 2. Locations of offices of the U.S. Geological Survey Caribbean-Florida Water Science Center, and extents of Florida Water Management Districts. U.S. Geological Survey Water Resources Research Institutes are located in Florida, Puerto Rico, and the U.S. Virgin Islands.
Geographic, Climatic, and Hydrogeologic Setting
The geographic domain of the Caribbean-Florida Water Science Center has one of the most varied geographic, climatic, and hydrogeologic settings of Water Science Centers in the Nation. Florida is part of the Coastal Plain physiographic province which extends along the Gulf Coast, from Texas, to Florida, and to New England (fig.2, inset map). In Florida, much of the Coastal Plain is referred to as the Floridian section, which includes the "peninsular" of Florida and is underlain by a thick sequence of Tertiary-age carbonate rocks. The Floridian section is largely low-lying terrain with higher elevations along the central axis of the peninsular. Higher elevations are generally underlain by Tertiary-age clastic rocks (which overlie Tertiary-age carbonates), associated with marine terraces. High areas include the Lake Wales Ridge, which is associated with marine terraces and beach deposits that formed during higher sea-level stands during the Tertiary Period. A prominent peak of the Lake Wales Ridge is Sugarloaf Mountain, at 312 feet above sea level (fig. 3). The maximum elevation of Florida is 345 feet in the Florida Panhandle.
The climate of Florida is classified as subtropical and tropical. Annual rainfall for 1901–2014 averaged 54 inches (estimated from Parameter-elevation Regression on Independent Slopes Model; Daly and others, 2008). Rainfall falls primarily during summer months as convective precipitation, with Florida having a reputation as the “lightning capital” of the Nation. Annual temperature for 1901–2014 averaged 71 degrees Fahrenheit. High temperatures are associated with high evaporation and transpiration rates; in parts of the State, evaporation from open water bodies can exceed the precipitation rate (German, 1996; https://fl.water.usgs.gov/et/).
The hydrogeologic framework of Florida is described by Williams and Kuniansky (2012). The numerous lakes in the lowlands parts of the Floridian section reflect the karst terrane, resulting from dissolution features and sinkholes developed in Tertiary-age limestones. Several major springs in Florida emanate from karst features. There are 320 known springs in the State, and Spring Creek and Crystal River Springs had the largest discharge in the State (as compiled by Spechler and Schiffer, 1995). Major aquifers in Florida include the Floridan aquifer system, intermediate aquifer system, and surficial aquifer (fig. 4). The Floridan aquifer system includes Tertiary-aged carbonate rocks, and is subdivided into the Upper Floridan aquifer and Lower Floridan aquifer. Discontinuous composite units separate the Upper and Lower Floridan aquifers. The Upper Floridan aquifer is a major source of freshwater for much of central and northern Florida; in southern Florida the Upper Floridan aquifer is brackish to saline and younger units (Biscayne and surficial aquifers) are a source of water supply.
Figure 3. Selected geographic features in Florida. B=Broward County; M=Monroe County; MD=Miami-Dade County; PB=Palm Beach County.
Figure 4. Conceptual model of aquifer systems of Florida.
Overlying the Floridan aquifer is the upper confining unit which includes the Tertiary-age Hawthorn Group. Locally, the Hawthorn Group can have properties of an aquifer and is referred to as the intermediate aquifer system. In Georgia, this aquifer is referred to as the Brunswick aquifer system. Overlying the Hawthorn Group Quaternary-age surficial aquifer systems, which in southern Florida includes the Biscayne aquifer. The Biscayne aquifer is a freshwater source for south Florida.
Puerto Rico and the Virgin Islands are located in the northeast Caribbean Sea; Puerto Rico is the easternmost island of the Greater Antilles (which includes Cuba, Jamaica, Haiti, Dominican Republic, and Puerto Rico), and the U.S. Virgin Islands is in the northwesternmost part of a chain of smaller islands referred to as the Lesser Antilles (fig. 1). Renken and others (2002) described the hydrogeology of Puerto Rico and the U.S. Virgin Islands. Both Puerto Rico and the U.S. Virgin Islands have rugged topography and relief, with elevations reaching 4,390 feet (Cerro de Punta) in Puerto Rico and 1,555 feet in the U.S. Virgin Islands. The topographic setting of Puerto Rico is that of central highlands surrounded by flat-lying coastal plains and alluvial valleys (Murphy and others, 2012). Mountain ranges are oriented east-west and include, from east to west, the Cordillera Central, Sierra de Cayey, and Sierra de Luquillo (fig. 5). Mountain ranges produce orographic precipitation patterns with windward northern slopes receiving up to 200 inches of precipitation, and leeward southern slopes receiving less than 40 inches of precipitation.
Figure 5. Selected geographic features of Puerto Rico.
Groundwater provinces of Puerto Rico are associated with topography, and include the upland Interior Province, and the lowland North Coast and South Coast provinces, as well as several minor groundwater provinces (fig. 6). The generalized geology includes volcanicastic, volcanic, and igneous intrusive rocks underlying the Interior Province, flanked by limestone and clastic rocks (gravel, sand, silt, clay) in surrounding lowlands and valleys. Major aquifers in Puerto Rico include the South Coast aquifer and North Coast limestone aquifer system.
The largest island of the U.S. Virgin Islands is St. Croix, which has upland areas of the Northside Range and East End Range, separated by the Central Limestone Plain (fig. 7). Ranges are underlain by mafic intrusive igneous rocks. Lowlands include exposures of carbonate rocks (Blessing Formation and Kingshill Limestone) and alluvial deposits. Aquifers of St. Croix include the Kingshill aquifer.
Figure 6. Ground-water provinces of Puerto Rico (modified from Renken and others, 2002; and McGuinness, 1948).
Figure 7. Geologic map and physiographic provinces of St. Croix, U.S. Virgin Islands (modified from Renken and others, 2002; Whetten, 1966; and Gill 1989).
Marella (2012) estimated the total water use in Florida at 14,237 million gallons per day (Mgal/d). Saline water accounted for 55 percent of the total, and freshwater accounted for 45 percent (6,383 Mgal/d) of the total. Groundwater accounted for 65 percent of freshwater withdrawals, and surface water accounted for the remaining 35 percent. Surface water accounted for nearly all saline-water withdrawals, and was primarily used for power generation. Agriculture accounted for 39 percent of the total freshwater withdrawals (groundwater and surface water), followed by public supply (36 percent). Public supply and agriculture accounted for the majority of groundwater withdrawals (49 and 34 percent, respectively), followed by commercial-industrial-mining self-supplied (7 percent), recreational-landscape irrigation and domestic self-supplied (5 percent each), and power generation (less than 1 percent). Marella (2012) reported that the largest percentage of freshwater withdrawals was from the South Florida Water Management District (46 percent; fig. 1), followed by the Saint Johns River Water Management District (20 percent), Southwest Florida Water Management District (19 percent), Northwest Florida Water Management District (9 percent), and Suwannee River Water Management District (6 percent).
Molina-Rivera (2014) compiled water use data for Puerto Rico during 2010, and indicated that public-supply water constituted the major freshwater use (677 Mgal/d). The population served by public-supply facilities operated by the Puerto Rico Aqueduct and Sewer Authority (PRASA) was estimated to be 96 percent of the total population for Puerto Rico in 2010 (about 3,586,200 inhabitants). Non-PRASA public-supply water withdrawals were estimated at 7.04 Mgal/d, and serve a population of about 101,600. Public-supply domestic use in Puerto Rico was estimated at 206 Mgal/d; and domestic self-supplied use was estimated at 2.41 Mgal/d (population of about 37,900). Ground-water withdrawals for industrial use was estimated at 4.30 Mgal/d; and crop-irrigation withdrawals were estimated at 38.2 Mgal/d. Ground-water withdrawals from the South Coast Province and North Coast Province were 57.5 and 39.9 Mgal/d, respectively. In 2010, Puerto Rico had four thermoelectric powerplants that used large amounts of seawater. Nine active hydroelectric powerplants had an instream freshwater use of 556 Mgal/d.