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- Info
Water table management on a watershed scale
| Author: |
Evans, R.O.; Parsons, J.E.; Stone, K.; Wells, W.B. |
| Date: |
1992 |
| Periodical: |
Journal of Soil and Water Conservation |
| Abstract: |
Channel water table control can improve water use efficiency within a watershed; reduce demands on other water sources to facilitate-irrigation; improve crop yields; and reduce the transport of fertilizer nutrients, in particular nitrogen, to sensitive receiving surface waters. The magnitude of the benefits associated with stream water-level control vary among watersheds and from year to year within a given watershed. The success of watershed-scale projects will be influenced by soils, crops, and topography within the watershed; the percentage of the watershed area cropped; hydraulic properties of the watershed; seasonal rainfall; and management strategies. Most of the poorly drained soils in the Coastal Plain and Tidewater regions of the Atlantic and Gulf States would respond to water table management. Most drainage improvement and flood prevention projects authorized and constructed under PL-566 would respond to watershed-scale projects. Water table management on a farm-unit basis is popular in some states, but watershed-scale projects have been slow to develop. The technical feasibility of water table management on both a farm-unit basis and watershed scale is fairly well documented. There still remains a need, particularly for watershed-scale systems, to improve and fine tune management strategies to optimize the net benefits of water table management. This need will become more acute as more field scale systems are expanded to include entire watersheds. In some areas, field-scale projects already are developed to the extent that some landowners would like to expand to watershed-scale projects. At this time, institutional problems present barriers to developing these watershed scale projects. Until water rights and institutional problems and concerns associated with watershed-scale projects are addressed and clarified, such projects likely will continue to develop slowly. Authority provided to drainage districts to develop PL-566 drainage and flood prevention projects does not appear adequate to address watershed scale water table management problems that are arising. |
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