Study Reveals the Role of Forests in Providing Drinking Water to the Population of Puerto Rico

A map shows the municipalities and population served by water originating on the El Yunque National Forest in Puerto Rico.Puerto Rico is densely populated with 3.7 million people living primarily on the mainland island. Forests that make up about 54.7 percent of the land cover are important for the islands’ water supplies. Eastern Threat Center researchers and partners used the Water Supply Stress Index (WaSSI) model, which estimates monthly water balance and flow routing, to quantify the amount of water originating at forested watershed outlets. To quantify the population that relies on this water, researchers used water intake location data from the U.S. Geological Survey and population served data from the Puerto Rico Aqueduct and Sewer Authority. They estimated that all lands in mainland Puerto Rico produce 6.5 billion m3/year of water. Of that total, National Forest System lands (3.3% of total land area) provide 219 million m3 of water, and commonwealth and private forest lands (40% of total land area) provide 2.6 billion m3 of water. This water serves a population of 3.6 million people from 113 intakes located downstream of commonwealth and private forest lands. Thirteen of the intakes that serve 780,000 people are located downstream of El Yunque National Forest, which receives relatively high precipitation and produces the highest runoff in the mainland. This analysis provides quantitative information on water yield from forested lands and sources of water supply in Puerto Rico.

Pictured: A map shows the municipalities and population served by water originating on the El Yunque National Forest in Puerto Rico.Image by Erika Mack, U.S. Forest Service.

Related publication:

Forest Service Partners/Collaborators:
Southern Region (Region 8) and Southern Research Station Coweeta Hydrologic Laboratory

External Partners/Collaborators: Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD) / Jiangsu Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science & Technology

Contact: Erika Mack, resource information specialist,; Ge Sun, research hydrologist,

Next -->

<-- Previous

Document Actions
Personal tools

For the latest up-to-date ag webinars on all things agriculture, visit the Agriculture Webinars Portal