Article
French
ID: <
10670/1.9q7jsi>
Abstract
The so called “low fall” hydroelectric projects that are located along important river low flows often set the grave conservation problem of the alluvial plain underground water resources. The worked out by Electricité de France Golfech project on the river Garonne, some kilometers from Agen, is a particularly demonstrative example of it. There, were used most of technics intending to avoid the damageable consequential effects on the alluvial water-table during as well the provisional working stage as the final operating stage of the project. These technics were : — water-table artificial supply during works ; — impervious cut-off to avoid drainage by the outlet canal ; — particular dimensioning and arrangements of the inlet canal to allow the underground water to flow ; — water-table regulating outlet pipe behind lateral dicks along the pool ; — sills in the river to set up again the downstream underground flowing conditions after diversion. No difficulty was noted during works as well on the job itself as for the water-table customers. The project operates since 1973 and the underground water-table behaviour is still satisfactory.