Permanent groundwater control

Many factors relating to the design of a temporary de­watering or pressure relief system are equally applica­ble to the design of permanent groundwater control systems. The principal differences are the require­ments for permanency and the need for continuous operation. The requirements for permanent drainage systems depend largely on the structural design and operational requirements of the facility. Since perma­nent groundwater control systems must operate con­tinuously without interruption, they should be con­servatively designed and mechanically simple to avoid the need for complicated control equipment subject to failure and the need for operating personnel. Perma­nent drainage systems should include provisions for inspection, maintenance, and monitoring the behavior of the system in more detail than is usually required for construction dewatering systems. Permanent sys­tems should be conservatively designed so that satis­factory results are achieved even if there is a rise in the groundwater level in the surrounding area, which may occur if water supply wells are shut down or if the efficiency of the dewatering system decreases, as may happen if bacteria growth develops in the filter sys­tem. An example of a permanent groundwater control system is shown in figure 1-2.

IMPERVIOUS BACKFILL PERVIOUS BACKFILL

 

DISCHARGE

 

Permanent groundwater control

. (Fruco&. Associates, Inc.)

U. S. Army Corps of Engineers

Figure 1-2. Permanentgroundwater control system.