The Oso Creek gage is immediately west of Corpus Christi and represents an area of mostly cropland. The Seco Creek gages are northwest of Hondo, Texas which is in the upper reaches of the Nueces River basin. The Seco gages represent the only data appropriate to rangeland for the study area. In general, the potential for agricultural nonpoint source pollution is lower in the study area than in most other areas of the state. Nearly all of the soils classified as Highly Erodible Land by the NRCS are farmed under approved conservation systems.
Slopes are relatively flat throughout the study area, especially in the agricultural cropland areas.
There is insufficient available data to further categorize the EMC values by watersheds or by seasonal variation. As part of this report, a pilot study is included for comparison of state of the art watershed models. The Oso Creek Watershed was selected for use in this pilot study comparison. Estimated runoff and loadings are shown to be highly variable, depending on annual rainfall. The compilation of an EMC data base according to land use categories represents an important first step in characterizing stormwater runoff quality.