Sedimentation Survey of Lago Patillas, Puerto Rico, March 2007

Scientific Investigations Map 3128



Lago Patillas is a reservoir located on the confluence of Rio Grande de Patillas and Rio Marin, in the municipality of Patillas in southern Puerto Rico, about 3 kilometers north of the town of Patillas and about 8 kilometers northeast of the town of Arroyo (fig. 1). The dam is owned and operated by the Puerto Rico Electric Power Authority (PREPA) and was constructed in 1914 for the irrigation of croplands in the southern coastal plains of Puerto Rico along the towns of Arroyo, Guayama, Patillas, and Salinas. Irrigation releases are made through the outlet works into the Patillas Irrigation Canal that extends 32.2 kilometers from the Patillas dam to Rio Salinas. The dam is a semi-hydraulic earthfill with a structural height of 44.80 meters, a top width of 4.57 meters, a base width of 190.49 meters, and a crest length of 325.21 meters. The spillway structure is physically separated from the earthfill dam, has an elevation of 58.21 meters above mean sea level, and has three radial arm gates (Puerto Rico Electric Power Authority, 1979). The reservoir impounds the waters of the Rio Grande de Patillas and Rio Marin. The reservoir has a drainage area of 66.3 square kilometers. Additional information and operational procedures are listed in Soler-Lopez and others (1999). During March 14-15, 2007, the U.S. Geological Survey (USGS), Caribbean Water Science Center (CWSC), in cooperation with the PREPA conducted a bathymetric survey of Lago Patillas to update the reservoir storage capacity and update the reservoir sedimentation rate by comparing the 2007 bathymetric survey data with previous 1997 data. The purpose of this report is to update the reservoir storage capacity, sedimentation rates, and areas of substantial sediment accumulation since April 1997.

Study Area

Publication type Report
Publication Subtype USGS Numbered Series
Title Sedimentation Survey of Lago Patillas, Puerto Rico, March 2007
Series title Scientific Investigations Map
Series number 3128
DOI 10.3133/sim3128
Year Published 2010
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Caribbean Water Science Center
Description 1 Plate: 36.34 x 23.97 inches
Country United States
Other Geospatial Lago Patillas;Puerto Rico
Datum Puerto Rico Datum (1940 adjustment)
Projection Lambert Conic Conformal Projection
Online Only (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details