Case Study- San Pedro Basin GW-SW Interactions, April 19th

Links: [Presentation]

1. Principles and characteristics of the basin
- transboundary watershed i.e. 4.480 km2  (1810 Mexico and 2670 USA), Mexico is located upstream.

2.  Main Characteristics in the US part of the basin
- San Pedro Riparian Natural Conservation Area
- During 2005, the river ran dry

The problem is that between 1935 and 2005 i. the stream flow decreased both in the winter and the summer and ii. Pumping increased significantly.

Until 2004 the studies that were implemented were conventional (hydrology, geomorphology and groundwater measurements)

3. Sustainability of Groundwater

Further studies were implemented concerning ecology and its relationship to hydrology including:
i. detailed study of the ecosystem
ii. further development of the conceptual model and
iii. development of a mathematical model.

Issues:
- What are the techniques to calculate natural run-off
- Geohydraulic studies include: water levels, stream flows, aquifer storage changes (using the micro-gravity method) unsaturated zone flow, stream temperature monitoring
- Is it possible to recognize the changes of water levels based on surface and/or groundwater variations?

4. Sustainable Approach for Water Utilization in the San Pedro

- Definition “The development and use of groundwater in a manner that can be maintained for an indefinite period without causing unacceptable environmental, economic or social consequences.”

Personal Considerations: based on the map/ model of the area (including storage changes.)

Technical Aspects- Reduce pumping near the river and increase it far from the course to guarantee ecological run-off and to minimize social- economic effects

Management Aspects- consider the management of the total watershed including the fact that it is a transboundary watershed.

Blog reporters: Jorge Santa Cruz and Miguel Angel Giraut