Page 17 - Water Every Drop Counts

evaporates from leaves and soil, some runs over the surface and forms streams while some percolates
into the soil where it may be drawn on by plants and transpired back into the atmosphere or returned
to the surface by soil capillarity.
Some soil moisture evaporates from the surface while the rest percolates down below to join the
groundwater. Groundwater often, but not always, percolates through pores in the soil and rocks to
reappear on the surface at lower elevations as a spring or as seepage into streams and rivers, which
eventually re-enter the ocean. Still some continues to lie in the groundwater reservoir or aquifer till it is
tapped by a mechanical tube well or an open well.

WATER STORAGE STRUCTURES

A DAM is a barrier constructed across
a waterway to control the flow or raise
the level of water, often to give it the
elevation needed for generation of hydro-
electrical power. Dams generally serve
the primary purpose of retaining water,
while other structures such as floodgates
or levees (also known as dikes) are used
to manage or prevent water flow into
specific land regions.

A BARRAGE consists of a line of large sluice
gates that can be opened or closed to control
the amount of water passing through them.
Barrages are important to regulate flow of
water during various seasons for managing
needs of downstream communities.

CHECK DAMS are used to break the flow of
water in small streams and water courses. The
objective is to accumulate water for future usage
as well as to make it seep back into the ground
and recharge underground aquifers.

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