|
|
- Info
Urban hydrology for small watersheds
| Date: |
1975 |
| Periodical: |
Technical Release 55. U.S. Department of Agriculture, Soil Conservation Service, Engineering Division |
| Abstract: |
This technical release analyzes the effects of urbanization in a watershed on hydraulic and hydrologic parameters and presents methods of estimating runoff volume and peak rates of discharge. Obtaining basic data on runoff volume and peak rates of discharge is difficult because conditions are constantly changing during the transition from rural to urban land use. At this time only general empirical relationships between the parameters that affect runoff and peak rates of discharge can be developed. Much research is being undertaken to better analyze the effects of urbanization through collection of runoff data and study of watershed models. Reports of progress in this field are being made continually. For additional information see the bibliography in appendix A. As population density and land values increase, the effects of uncontrolled runoff become an economic burden and a serious threat to the health and well being of a community and its citizens. Emphasis must be placed on providing solutions .to the water problems caused by radical changes in land use. Estimating the magnitude and frequency of future flood events makes possible systematic planning and installation of structural and nonstructural measures to reduce hazards to acceptable levels. Management of runoff from even minor storms is rapidly becoming an engineering requirement of local and state governments to help reduce flooding and stream erosion. Rapid deterioration of stream channels caused by increased storm runoff has had a detrimental impact on communities. Counties and states are adopting policies which limit the effects that changes in land use may have on the stream regimen within a development or watershed. These policies cover such areas as (1) assisting in the planned management of water resources, including storm drainage, throughout the watershed; (2) promoting and encouraging the inclusion of flood storage in all planned reservoirs; and (3) encouraging and assisting in planning for onsite retention of runoff through the use of temporary storage structures and infiltration devices. There is a need for thorough understanding of the problems associated with the rapid conversion of land use and for adequate technical procedures to assist local communities, municipalities, and planning groups in assessing the effects of changed land use on stream flow. |
|
