posted on 2010-07-02, 15:22authored byMukund G. Shinde, S.D. Gorantiwar, Ian Smout
Watershed development projects in India have proved their utility in
making more water available for drinking and crop production and conserving the
soil resources in the fragile rural ecosystems. Water harvesting structures viz. nala
bunds, percolation tanks, farm ponds are the main structures which create surface
water and groundwater storages in watershed. These structures are effective in
creating more surface and groundwater resources but there is lack of an analytical
tool for designing these structures optimally. This often results in non optimal
rainwater harvesting through these structures.
The combination of one or more harvesting structures in watershed is referred to as
watershed based tank system in this paper. These systems have some unique
characteristics and requirements. While designing the tank system one has to decide
the number of tanks, their locations and type. Tank type depends on the orientation
of command area around the tank. The in situ treatments like CCT in the catchments
of these tanks affect the inflow to the tank. To avoid upstream-downstream conflict
some portion of runoff needs to be allowed to go downstream of the watershed.
SOFTANK (Simulation Optimization For Tanks) model has been developed which
takes into account all these characteristics. This paper discusses the SOFTANK
model and its application for evaluation of percolation tanks in the Pimpalgaon
Ujjaini watershed in the scarcity region of the Maharashtra state of India.
In Pimpalgaon Ujjaini watershed there are two tanks at stream point No 3 and 6 with
capacities of 695877 and 216937 m3 (total storage capacity 912814 m3). These tanks
are used for groundwater recharge only. The water balance analysis of two
percolation tanks of Pimpalgaon Ujjaini watershed was carried out with the
SOFTANK model for 29 years (1975 to 2003). Model showed that 42% runoff is
harvested by the tanks and 58% goes out of the watershed. Seepage was the major
(84%) outflow component from the tanks. The tanks are overdesigned and therefore
any in situ soil water conservation works in the catchments of these tanks should be
discouraged.
History
School
Architecture, Building and Civil Engineering
Research Unit
Water, Engineering and Development Centre (WEDC)
Citation
SHINDE, M.G., GORANTIWAR, S.D. and SMOUT, I.K., 2010. Evaluation of percolation tanks in a semitropical watershed in India using SOFTANK model. 3rd International Perspective on Current & Future State of Water Resources & the Environment, EWRI-ASCE, Chennai, 5-7 January 2010.
Publisher
EWRI-ASCE
Version
NA (Not Applicable or Unknown)
Publication date
2010
Notes
This is a conference paper. Further details of this conference can be found at: http://content.asce.org/conferences/india2010/index.html