Types of check dams

A) Brushwood check dams

:

• Constructing brushwood check dams conserves small gullies up to 1.2 m to 2.1 m deep. These are classified into;

a) Single row brushwood check dams.

b) Both row brushwood check dams

B) Semi permanent dams:

• these dams are more stable than brushwood check dams.

These are following types;

a) Dry stone check dams: it is made up of dry stones without mortar.

b) Log Dams: when timber is available it is used for making log dams.

C)Permanent check dams:

• They are built in deeper and wider gullies where no other measures can stop erosion. They are of following types;

a) Drop spillway: it is an efficient structure for controlling relatively low head upon 3m and discharge capacity of 3m3/ sec.

b) Chute spillways: it is useful in high overfalls where a full flow structure is required and where site condition do not permit the use a detention type of structure.

c) Gabions: it uses pre- fabricated rectangular basket called gabion made up of galvanized wire netting. The basket is placed in position and filled with stones, and then the lid is wired down.