Abstract: May 29  10:50 AM (BACK)

Southwest Watershed Restoration

Bruce Cole
River Specialists
San Antonio, TX

Southwest watersheds have significant challenges in maintaining water quantity and quality. They face a number of stressors such as long term drought, intense urbanization and growth, poor land use practices, over grazing, water withdraws, pollution, mining and invasive species. Watershed managers need to balance the water needs and quality of municipalities and private land owners while at the same time meeting the hydrological, biological and chemical functions of ecosystems and should adopt a watershed planning concept. Planning, managing and restoring from a watershed perspective are more effective than the traditional piecemealing restoration approach. A holistic, watershed-scale approach to restoration considers the cumulative effects on overall watershed function.

The southwest can generally be described by its “basin and range” topography. Throughout the basin and range region, interior watersheds in close proximity can be very different from each other in terms of their physical and ecosystem characteristics. Individual watersheds are more aptly described in terms of their unique physiographic features and biotic communities, including highly variable soils, underlying geology, upland and riparian vegetation, and climate. This variability poses unique challenges to current restoration methodology.

Compared to 59% ephemeral streams in the whole United States the southwest is comprised of 81% ephemeral streams. This high percentage of ephemeral streams could pose problems for out of state practitioners whose work has been in “wet” streams. Ephemeral streams are important because they provide the same critical functions as perennial streams. They transport sediment and water, nutrients, chemicals and other debris as well as provide connectivity within the watershed. In the southwest, an understanding of local hydrology, climate, vegetation, fluvial processes, and relationship between surface and groundwater is needed to ensure restoration success. This presentation will focus on unique challenges of watershed restoration in Texas.