Erosion in the desert environment can be manifested in many ways (Figure 3.5, “Existing Natural Stormwater Conveyance Channel with Minor Erosion”). What begins as small rills within upper portions of watersheds concentrates into small channels. As small channels collect and combine within the watershed, washes are formed. Depending on the slope and stability of the channel material (sand, cobbles, bedrock, etc.), large washes and possibly deep gullies may occur.

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Figure 3.5. Existing Natural Stormwater Conveyance Channel with Minor Erosion

Soils in the project area consist primarily of gravelly sand and sand/clay loam, with some cobble to boulder size material. Table 3.3, “Soil Types within the Walking Box Ranch Site” lists local soils mapping from the National Soil Conservation Service. The soils in the project area tend to be well-drained soils with moderate to high runoff potential. The upper regions of the drainage basin tend to have a higher erosion potential as a result of steeper slopes. The project site, however, is located in the valley with a flatter grade and less erosion potential.