Stream Gauges. In San Xxxx Obispo County, there are a variety of stream flow monitoring needs, due to the mix of urban and rural watersheds. Information gained from stream flow monitoring is necessary for land use and water resources planning and for flood warnings and forecasts. Stream flow monitoring may be used to study the effects of recent land use changes in the county due to agricultural and urban development. Heavily irrigated crops such as vineyards have replaced dry-land farming in some areas, increasing the demand on groundwater basins, which rely on recharge from streams. In expanding urban areas, impervious surfaces have replaced open fields and croplands. New monitoring stations are necessary to evaluate existing water resources. In areas with a high demand for groundwater, stream flow monitoring is used to create a water balance and to determine a safe yield for the groundwater basin. Monitoring should be conducted on each of the major streams in the region, particularly in the north coastal part of the region. The coastal communities in the northern portion of the county, in particular, depend on ground water replenished by local streams for water supply. The major streams and rivers in the region include: • Xxxxxx De La Xxxx Creek • Xxxxxx Grande Creek* • Cayucos Creek • Chorro Creek* • Xxxxxxxx River* • Los Osos Creek* • Morro Creek* • Old Creek • Pismo Creek • Xxxxxxx River* • San Capoforo Creek • San Xxxx Obispo Creek* • San Simeon Creek* • Santa Xxxx Creek* • Toro Creek • Villa Creek Sites marked with an “*” indicate streams that have current gauge stations, and are shown as red circles in the figure below. There are seven major streams in the region that do not currently have stream gauges, as suggested in the above figure. Those streams are marked by a red cross (“+”) on the map above. (Existing streams are marked by a red circle.) Those streams include: • Xxxxxx De La Xxxx Creek • Cayucos Creek • Old Creek • Pismo Creek • San Capoforo Creek • Toro Creek • Villa Creek In order to measure stream flow at the outlet of each Hydrologic Catalog Unit within the region, stream gauges should be placed at the outlet of each of the above creeks. The Xxxxxxx River, Santa Xxxxx River, and Xxxxxxxx River watersheds all have USGS stream gauges that measure streamflow from their respective accounting units. When adding new sites to the stream network, using past, inactive gauges, which may have a period of record that will complement any new data collected, shoul...
