This is a wet rice cultivation cum fish farming system practiced
in elevated regions of about 1600 m and gentle sloping valleys,
having an average annual rainfall about 1700 mm and also rich
water resources like springs and streams. This system harvests
both ground and surface water for irrigation. It is practiced
by Apatani tribes of ziro in the lower Subansiri district of
In Apatani system , valleys are terraced into plots separated
by 0.6 meters high earthen dams supported by bamboo frames.
All plots have inlet and outlet on opposite sides. The inlet
of lowlying plot functions as an outlet of the high lying
plot. Deeper channels connect the inlet point to outlet point.
The terraced plot can be flooded or drained off with water
by opening and blocking the inlets and outlets as and when
required. The stream water is tapped by constructing a wall
of 2-4 m high and 1 m thick near forested hill slopes. This
is conveyed to agricultural fields through a channel network.