SURFACE WATER RESOURCES AND DRAINAGE SYSTEM
4.0 River & River Basin
State of Tripura is well endowed with surface water resources. As many
as ten major rivers is reported to generate an annual flow of 793 million
cubic meter of water. All rivers are rain-fed and ephemeral in nature.
All major rivers originate from hill ranges and show a typical drainage
pattern called trelis, except a few instances of dendrite pattern. Table-
19 provides a synopsis of the Rivers.
is obvious that much of the surface water passes through a combined distance
of 896 km flow into Bangladesh.
study of basin characteristics by CSME (1989) indicate that eight of the
ten basins are within the territorial limit of Tripura while basin areas
of river Fenni and Langai are shared by two Indian States viz. Tripura
and Mizoram and Bangladesh. Collectively basin area of ten major rivers
and other minor streams covers nearly 10,500 sq. km (Table-20). In terms
of percentage of the basin of individual rivers vis-a-vis, total basin
Gumti (22.66%), is followed by Manu-Deo (18.36%) and Khowai (13.13%).
Basin characteristics of the major rivers are given in the Table-20, along
with percentage shared by each.
total volumes of surface water generated in Tripura largely depend on
rainfall. A study of isohyte reveal that isohyte line with highest value
of 3000 mm passes through southernmost part of Tripura, north of Sarbum
while isohyte with 2750 mm-2500 mm value pass along North East-South West
axis and the isohyte with lowest value of 2250 mm pass through Sonamura-Udaipur
area. The pattern of intensity of rainfall changes differently in different
of the793 million cubic meters of surface flow in Tripura drain into the
country of Bangladesh. Actually
more than 67.5% of the total flow are carried by Gumti (249 mcm), Manu
(170 mcm) and Khowai (115 mcm) rivers. While other rivers carry 32.5%
of the total surface flow. The highest flow rate of surface water is recorded
for Gumti (1.05 lakh cubic meter) and the lowest being on Burima river
(0.2 lakh cubic meter). Flow characteristics of the rivers including shared
percentage in given in Table-21.
may be noted that at least a part of surface water flow has been utilised
for generation of hydel power in Tripura. Two multipurpose river valley
projects viz. Gumti and Khowai are said to contribute 1.01 Mw of hydel
power to the State.
Table-20: Basin area and percentage of basin area of total geographical area
Characteristics of River
Rivers and Flood
available data indicate that all the rivers originating in the hill ranges
can cause flood in heavy rainfall. Flood level of at least five of the
major rivers show that the danger may vary from 1.48 meter for Haora River
near Agartala to 31.50 meter for Dhalai river near Kamalpur. Table-22
show the recorded danger level, extreme danger level and highest flood
level observed, for five of the major ten rivers of Tripura.
level of five major rivers
: Flood Investigation Division, GoI]