Watershed Management/Water Quality
| Project: | Assessing the risk of surface water contamination of Cryptosporidium parvum from beef cattle production: Implications for land use restrictions |
| Project Leader: | Rob E. Atwill |
| Summary: | 1995. Proc., UC Sierra Foothill REC Beef and Range Field Day:pp.15-17. The critical issue is how would Cryptosporidium parvum from calves gain access to surface waters and end up in drinking water supplies. The essential steps must include calves becoming infected and shedding the oocysts in their feces. These oocysts must then enter a surface water supply and remain infective as they journey downstream to water treatment plants and distribution systems. The scientific evidence supporting the claim that cattle are a significant source of C. parvum for surface water is incomplete and contradictory in some cases. It is premature at this time to claim that cattle production is a leading source of C. parvum in surface water. |
| Project: | A model nonpoint source management plan for hardwood rangeland |
| Project Leader: | Connor, J. M., and M. Joyce |
| Summary: | Proc., Symp. on Oak Woodlands: Ecology, Management, and Urban Interface Issues. San Luis Obispo, CA., Mar. 19-22, 1996. The state water resources control board has adopted and is beginning to implement the California rangeland water quality management plan (CRWQMP). This plan was initiated by the state's livestock grazing industry as a proactive means for addressing Federal clean water act water quality requirements for California's rangelands. We developed a plan for management of the hardwood rangeland. It's objectives are to guide resource use at the Center and to serve as a practical example for grazing land managers as they write their own plans as suggested by the CRWQM plan. Ref.255\64.01. |
| Project: | An example of a rangeland NPS management plan |
| Project Leader: | Connor, M., and M. Joyce |
| Summary: | 1995a. Proc., UC Sierra Foothill REC Beef and Range Field Day: pp. 18-26. A rangeland management plan was developed for SFREC which can serve as a model plan for management of non-point source (NPS) water pollution. Plan steps include assessment of the resource (including any pollution sources); setting to meet the goals; and monitoring to determine whether management activities are effective. |
| Project: | Problem assessment on rangeland watersheds |
| Project Leader: | Connor, M., and M. Joyce |
| Summary: | 1995b. Proc., UC Sierra Foothill REC Beef and Range Field Day: pp. 36-38. In order to develop a rangeland management plan, any existing problems have to be identified. It is important to realize that many existing management methods are effectively reducing water pollution. These methods may already adequately meet many Water Quality Control Board requirements, especially if local water bodies are not impaired. There also may be some simple and relatively inexpensive management procedures that can be adopted that can substantially reduce water pollution from a rangeland watershed. |
| Project: | Measurement of nitrous oxide dissolved in soil solution |
| Project Leader: | Davidson, E.A., and M.K. Firestone |
| Summary: | 1988. Soil Sci. Soc. Am. J 52: pp. 1201-1203. Degassing of soil solution as soil water enters springs and streams may be a significant pathway of N2O release into the atmosphere. A simple method is presented to sample soil solution to include gases dissolved in solution. Small porous cup lysimeters connected to narrow diameter nylon tubing were flushed with N2 gas; a vacuum was applied with an evacuated serum bottle; and solution and gases were captured in the bottle. Concentrations of N2O in soil solution of a grassland in central California varied from below ambient to 13 times ambient. At a wet riparian zone site, N2O in soil solution appeared to be related to NO3- concentration, which can be determined from the same soil solution sample. Ref.301\64.37. |
| Project: | Hydrologic impacts of blue oak harvesting and evaluation of the modified USLE in the northern Sierra Nevada |
| Project Leader: | Epifanio, C.R. |
| Summary: | 1989. M. S. Thesis, Univ. of Calif., Davis. 144 pages. The original objective of this project was the determination of the impacts of vegetation-type conversion and other range management techniques on water yield and water quality from a rangeland watershed. Six years data for rainfall, runoff and sediment yield for two watersheds, S1 and S2, have been reduced, tabulated, placed into a computer database and statistically analyzed. The watersheds were found to be sensitive to rain intensity and amount. Runoff tends to increase linearly with rainfall. In view of the fact that the SCS tolerable annual soil loss limits for the SFRFS are 5 tons per acre per year, none of the watersheds posed serious erosion problems during the study period. Ref.137\62.27. |
| Project: | Water quality and nutrient aspects of annual rangeland as influenced by range improvement |
| Project Leader: | Epifanio, C., and M.J. Singer |
| Summary: | 1987 Proc., UC Sierra Foothill Range Field Station Beef and Range Field Day: pp. 48-55. We have found that sediment and nutrient losses tend to be small for both watersheds studied in the Schubert area. The careful removal of oaks, according to the methods prescribed by the field station, did not have an effect on either runoff or water quality. However, we do not have sufficient data to come to any conclusions about the impact of vegetation removal on sediment yield. Additional years of data will be collected to determine, more conclusively, if type conversion has an effect on water quality. Studies of this kind are, of necessity, long term because of the highly variable precipitation and responses to precipitation. |
| Project: | Hydrologic Impacts of Oak Harvesting and Evaluation of the Modified Universal Soil Loss Equation |
| Project Leader: | Epifanio, C.R., M.J. Singer, and X. Huang |
| Summary: | 1991 Proc., Symp. on Oak Woodlands and Hardwoods Rangeland Mgmt., USFS Tech. Rep. PSW-126: pp. 221-224. Two Sierra foothill watersheds were monitored to learn what effects selective oak removal would have on watershed hydrology and water quality. We also used the data to generate sediment rating curves and evaluate the modified universal soil loss equation (MUSLE). Annual sediment rating curves better accounted for the variability in precipitation events from year to year, which may be at least as important as total rainfall, on the amount of runoff and sediment yield. The MUSLE predicted quite accurately when calibrated for these watersheds. |
| Project: | Rangeland water quality |
| Project Leader: | George, M., and J. Clawson |
| Summary: | 1993 Proc., UC Sierra Foothill REC Beef and Range Field Day: pp. 17-23. Before 1960, water pollution emphasized control of "point sources"--sewer pipes or industrial waste outlets--where a single discharge point could be identified and corrective action taken to reduce the pollutant load to surface water or groundwater. In recent years increased attention has been focused on "nonpoint" sources of pollution--sources that are diverse and often difficult to identify and control and that may combine to impair water quality. Contributions from nonpoint sources are unavoidable--the natural leaching of chemicals from weathering soils or the fecal coliform bacteria added by wild animal populations. |
| Project: | Riparian restoration study |
| Project Leader: | McCreary, D. |
| Summary: | 1995. Proc., UC Sierra Foothill REC Beef and Range Field Day: pp. 34-35. This project was initiated to begin testing several approaches for restoring woody vegetation to areas near a perennial stream at the Sierra Foothill REC that were cleared of woody vegetation approximately 25 years ago. Another principal goal of this project was to develop a demonstration area for conducting field tours for land owners and managers, as well as for the general public, to show people how various riparian restoration approaches work, what kind of growth can be expected from plantings, and what changes in wildlife habitat and stream morphology are likely to result. We will continue to closely monitor this project; no conclusion is available at this time. |
| Project: | A portable rainfall simulator for erodibility and infiltration measurements on rugged terrain |
| Project Leader: | Munn, J.R., Jr., and G.L. Huntington |
| Summary: | 1976 Soil Sci. Soc. Am. J. 40: pp. 622-624. A portable rainfall simulator for field study of erosion potential and infiltration on mountainous terrain is described. Polyethylene tubes produce 3.2 mm drops which fall 2.5 m onto a 61 by 61 cm plot. The maximum rainfall intensity is 23 cm/hour. A 16% intensity variation across the plot area was measured, but the variation between separate simulated storms was <1% for identical intensity settings. The unit is suited to one man operation on slopes up to 60%. |
| Project: | Plant cover helps control rangeland erosion |
| Project Leader: | Singer, M.J., J. Blackard, and G.L. Huntington |
| Summary: | 1980. California Agriculture 34(10): pp. 8-10. Soil erosion by water is a two-part process. First, the impact of raindrops detaches soil particles from the main mass of soil. Then, water flowing over the soil surface transports this loose soil from the site of detachment. Proper range management can prevent large erosion losses by ensuring that an adequate plant cover exists during the rainy season. This means that grazing pressure must be controlled and that type conversion practices such as mechanical brush removal, burning, and cultivation need to be timed so that the soil is not bare during the rainy periods of the year. Further research is needed to quantify the relationship between soil chemical properties and erodibility. Ref.100\63.70. |
| Project: | Selective oak removal does not harm water quality |
| Project Leader: | Singer, M.J., X. Huang, and C. Epifanio |
| Summary: | 1990. California Agriculture 44(2): pp. 17-18. Measurements before and after removal of oaks from 14% of a 250-acre watershed indicated small but not statistically significant increases in the runoff/rainfall ratio and no change in nutrient or sediment removal. Careful, selective oak removal appeared to have no harmful effect on water quality. Ref.51\61.06. |
| Project: | Effect of mulch rate on soil loss by raindrop splash |
| Project Leader: | Singer, M.J., Y. Matsuda, and J. Blackard |
| Summary: | 1981. Soil Sci. Soc. Am.J 45: pp. 107-110. The effect oat straw has on splash detachment and soil transport was quantified on Auburn clay loam using 50 rainfall simulator events. Raindrops with 3.2 mm diameters were applied from a height of 2.5 m to 30 cm X 30 cm plots at an intensity of 76 mm/hour for 30 minutes. The slope was 9%. There was a linear correlation between the amount of straw cover and the decrease in the amount of soil moved. The amount of interrill flow of water did not decrease, indicating that the reduction in soil loss by interrill flow was actually due to the reduced rain splash detachment. Ref.269\64.05. |