The Transboundary Aquifer Assessment Program and the San Pedro River Aquifer Binational Report

Photo taken 19

August 2009

TAAP Workshop and Binational Advisory

Committee meeting

Development

of the

cooperative

framework by

the IBWC in

2009.

*Understand the current state of knowledge with respect to

climate, geology, soils, land cover, land use, and hydrology

of the Santa Cruz and San Pedro aquifers in this binational

context

*Compile and create a database of scientific information

from both countries

*Identify data gaps and identify what data would be

necessary to update, in a subsequent phase, the

hydrologic model of the aquifer system, including surface-

and groundwater interactions on a binational level

*International Boundary and Water Commission United States and Mexico. *For Mexico: National Water Commission and University of Sonora. *For the United States: United States Geological Survey, University of Arizona Water Resource Research Center.

Authority

Carried out by the US and Mexico in accordance with resolution 6 of Minute 242 of the International Boundary and Water Commission (IBWC), entitled “Permanent and Definitive Solution to the International Problem of the Salinity of the Colorado River,” and the "Joint Report of the Principal Engineers Regarding the Joint Cooperative Process United States-Mexico for the Transboundary Aquifer Assessment Program."

Objectives

Participating Agencies

The San Pedro Report: Table of Contents

1. INTRODUCTION

1.1.Background

1.2.Study Area

1.3.Study Objectives

1.4.Previous Studies

1.5.Geographical Context

1.6.Binational Socioeconomic

Environment

1.7.Binational Water Management

Environment

1.8.Technical Work Undertaken

1.9.Methodologies and Techniques

Applied 2. PHYSICAL GEOGRAPHY

2.1.Physiography

2.2.Hydrography

2.2.1.Hydrologic Region

2.2.2.Hydrometry

2.3.Climatology

2.4.Soils

2.5.Vegetation 3. HYDROGRAPHY AND

HYDROMETEOROLOGY

3.1.Climatological Analysis

3.2.Precipitation and Evapotranspiration

3.3.Surface Hydrological System

3.4.Drainage Types and Maximum

Stream Order

3.5.Terrain Slopes

3.6.Land Cover and Use

4. CONCEPTUAL GEOLOGIC MODEL

4.1.Regional Geographical Context

4.2.Stratigraphy

4.3.Structural Geology

4.4.Three-dimensional Geology of the

Subsurface

4.5.Depth to Basement and Structure

4.6.Characteristics of the Sedimentary Fill

5. PIEZOMETRY AND HYDRAULIC

PARAMETERS

5.1.Comprehensive Well Survey

5.2.Reconstruction of the History of

Groundwater Withdrawals

5.3.Analysis of System’s Piezometric Behavior

5.4.Definition and Interpretation of Subsurface

Hydraulic Parameters

6. HYDROGEOLOGY

6.1.Hydrogeological Basement

6.2.Hydrostratigraphic Units

6.3.Definition of the Aquifer System

7. HYDROGEOCHEMISTRY

7.1.Hydrogeochemical Sampling

7.1.Temperature and pH

7.2.Water Quality

7.3.Identification of Water Families 7.4. Electrical Conductivity and Total

Dissolved Solids

7.5.Stable Isotopes

8.CONCEPTUAL MODEL OF

HYDRODYNAMIC BEHAVIOR

8.1.Groundwater Flow System

8.2.Pre-development

Hydrodynamic Behavior

8.3.Post-development

Hydrodynamic Behavior

9. CONCLUSIONS AND

RECOMMENDATIONS

10. REFERENCES

Binational Maps Prepared in English and Spanish

- 20 Binational maps were generated with information about climate, hydrology, geology, land use, soil distribution, vegetation, etc.

- 11 Binational water quality maps were created with information on pH distribution, electric conductivity, groundwater temperature and concentrations of major ions (Ca, Cl, Mg, Na, K, HCO3, SO4).

- 2 Binational maps with information on groundwater levels for the year 2011.

The San Pedro Report will be the first-ever binational

aquifer assessment prepared and released

simultaneously in English and Spanish by the IWBC.

University of Arizona Water Resources Research Center

Elia M. Tapia, Dr. Sharon B. Megdal

The Binational Experience

Sharing data and information that are accepted in

both countries creates the basis for cooperation

and a common understanding in support of both

countries’ sustainable use and protection of water

resources, and achieving sustainable economic

development. In addition, the intellectual and

interpersonal interaction improves the relationships

needed to coexist in harmony at a local and

international level.

Recommendations from the Binational Team

In order to achieve better understanding of the transboundary aquifer systems,

the binational team recommends continuing the scientific collaboration on these

aquifers and on other priority aquifers along the United States-Mexico border.

The development of more complete, publicly available, shared databases

offering reliable information to the public can be used for planning and for

managing natural resources along the the border area.

Acknowledgements

This work was supported by the Technology and Research Initiative Fund, through the University of

Arizona Water Sustainability Program and Water Resources Research Center. We acknowledge the

work of to the technical team for this study, which included personnel from the two federal

governments (CONAGUA and USGS) and two state universities (University of Sonora and University

of Arizona) under the auspices of the International Boundary and Water Commission (IBWC).

Examples of

Mapping

Efforts

- Different classification units for

both countries were unified to

obtain a binational product.

Hydrostratigraphic Units Locator Maps

English and

Spanish version. Geology

Examples of Binational Maps

- English and Spanish versions available.