USGS

Surface-Water, Water-Quality, and Ground-Water Assessment of the Municipio of Mayagüez, Puerto Rico, 1999-2002

By Jesús Rodríguez-Martínez, Luis Santiago-Rivera, Senén Guzmán-Ríos, Fernando Gómez-Gómez, and Mario L. Oliveras-Feliciano

 

In cooperation with the
MUNICIPIO AUTÓNOMO DE MAYAGÜEZ, PUERTO RICO
OFFICE OF THE MAYOR

 

U.S. Geological Survey Water Resources Investigations Report 03-4317

 

This report is available as a pdf.


ABSTRACT

The surface-water assessment portion of this study focused on analysis of low-flow characteristics in local streams and rivers, because the supply of safe drinking water was a critical issue during recent dry periods. Low-flow characteristics were evaluated at one continuous-record gaging station based on graphical curve-fitting techniques and log-Pearson Type III frequency curves. Estimates of low-flow characteristics for 20 partial-record stations were generated using graphical-correlation techniques. Flow-duration characteristics for the continuous- and partial-record stations were estimated using the relation curves developed for the low-flow study. Stream low-flow statistics document the general hydrology under current land use, water-use, and climatic conditions.

A survey of streams and rivers utilized 37 sampling stations to evaluate the sanitary quality of about 165 miles of stream channels. River and stream samples for fecal coliform and fecal streptococcus analyses were collected on two occasions at base-flow conditions. Bacteriological analyses indicate that a significant portion of the stream reaches within the municipio of Mayagüez may have fecal coliform bacteria concentrations above the water-quality goal (standard) established by the Puerto Rico Environmental Quality Board (Junta de Calidad Ambiental de Puerto Rico) for inland surface waters. Sources of fecal contamination may include: illegal discharge of sewage to storm-water drains, malfunctioning sanitary sewer ejectors, clogged and leaking sewage pipes, septic tank leakage, unfenced livestock, and runoff from livestock pens. Long-term fecal coliform data from five sampling stations located within or in the vicinity of the municipio of Mayagüez have been in compliance with the water-quality goal for fecal coliform concentration established in July 1990.

Geologic, topographic, soil, hydrogeologic, and streamflow data were compiled into a database and used to divide the municipio of Mayagüez into five hydrogeologic terranes. This integrated database then was used to evaluate the ground-water potential of each hydrogeologic terrane. Lineament-trace analysis was used to help assess the ground-water development potential in the hydrogeologic terranes containing igneous rocks. Analyses suggest that areas with slopes greater than 15 degrees have relatively low ground-water development potential. The presence of fractures, independent of the topographic slope, may locally enhance the water-bearing properties in the hydrogeologic terranes containing igneous rocks. The results of this study indicate that induced streamflow generally is needed to sustain low to moderate ground-water withdrawal rates in the five hydrogeologic terranes. The ground-water flow systems in the hydrogeologic terranes are only able to sustain small withdrawal rates that rarely exceed 50 gallons per minute. Areas with a high density of fractures, as could be the case at the intersection of lineament traces in the upper parts of the Río Cañas and Río Yagüez watersheds, are worthy of exploratory drilling for ground-water development.

TABLE OF CONTENTS

Abstract

Sumario

Introduction

Previous Studies

Chapter A: Surface-Water Resources Assessment of the Municipio of Mayagüez, Puerto Rico, 1999-2002

Purpose and Scope

Methodology

Results and Interpretation

Low Flow at a Continuous-Record Gaging Station

Low Flow at Partial-Record Stations

Flow-Duration Characteristics

Drainage-Basin Area/Discharge Relation

Map Features

Potential Reservoir Sites

Flood-Prone Areas

Saltwater Wedge at Streams

Public Water-Supply Filtration Plants and Waste-Water Treatment Facilities

Chapter B: Sanitary Quality of Surface Water During Base-Flow Conditions in the Municipio of Mayagüez, Puerto Rico, 2000-01

Purpose and Scope

Background

Methodology

Field-Data Collection

Analytical Techniques

Results and Interpretation

Upper Río Guanajibo Basin

Quebrada Sábalos Basin (Barrios Sábalos and Río Hondo)

Caño Corazones Basin (Barrios Sábalos and Río Hondo)

Río Yagüez Basin

Quebrada del Oro Basin (Barrio Miradero)

Caño Boquilla Basin (Barrios Sabanetas, Río Cañas, and Miradero)

Río Grande de Añasco Basin

Chapter C: Hydrogeologic Terranes and Ground-Water Resources in the Municipio of Mayagüez, Puerto Rico, 1999-2002

Purpose and Scope

Methodology

Hydrogeologic Terranes

Ground-Water Quality

Delineation of Coastal Saline Ground-Water Zone

Lineament-Trace Analysis

Base-Flow Measurements

Results and Interpretation

Hydrogeologic Terranes

Mayagüez Hydrogeologic Terrane 1 (MayHT1)

Upper Zone

Lower Zone

Mayagüez Hydrogeologic Terrane 2 (MayHT2)

Mayagüez Hydrogeologic Terrane 3 (MayHT3)

Mayagüez Hydrogeologic Terrane 4 (MayHT4)

Mayagüez Hydrogeologic Terrane 5 (MayHT5)

Ground-Water Quality

Ground-Water Withdrawals

Lineament-Trace Analysis

Summary and Conclusions

Acknowledgments

Cited References

PLATES

  1. Streamflow and bacteriological data collection sites, selected hydrologic features, and sanitary classification of streams with drainage to or within the municipio of Mayagüez, Puerto Rico
  2. Hydrogeologic terranes, selected subbasins, geophysical transects, lineament traces, and well locations within the municipio of Mayagüez, Puerto Rico

The citation for this report, in USGS format, is as follows:

 

Rodríguez-Martínez, Jesús, Santiago-Rivera, Luis, Guzmán-Ríos, Senén, Gómez-Gómez, Fernando, and Oliveras-Feliciano, M.L., 2004, Surface-water, water-quality, and ground-water assessment of the municipio of Mayagüez, Puerto Rico, 1999-2002: U.S. Geological Survey Water-Resources Investigations Report 03-4317, 68 p., 2 pls.


You can DOWNLOAD THIS REPORT BELOW in Portable Document Format (PDF):

 

Report (2.3MB)

 

Plate 1 (3.5MB) shows: Streamflow and bacteriological data collection sites, selected hydrologic features, and sanitary classification of streams with drainage to or within the municipio of Mayagüez, Puerto Rico

 

Plate 2 (3.3MB) shows: Hydrogeologic terranes, selected subbasins, geophysical transects, lineament traces, and well locations within the municipio of Mayagüez, Puerto Rico

 

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Please visit http://pr.water.usgs.gov for more information about USGS activities in the Caribbean (Puerto Rico and the U.S. Virgin Islands).

 


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