Surface Water

Where possible, it is much more cost effective to restore existing tanks, than to build new tanks. Restoration can involve silt removal to increase the storage capacity of the tank and reduce evaporative loss. The silt can be used to restore the earthen bund, and any remaining silt can be applied to nearby farmland. The outflow structure can also be improved.

If the intention is to develop a tank by holding back a large amount of water, then the dam must be carefully designed (with the assistance of experienced local people or engineers).

In addition to controlling gully erosion, check dams also serve to slow the movement of water, allowing increased percolation into the soil. Just above a check dam is a good place to put in a percolation structure. Silt that builds up behind the dam creates good farmland, which can be planted after the rains while it retains moisture. The following series of pictures show one farmer’s success with building a percolation tank just upstream of a series of check-dams.

Over the years, unchecked soil erosion can lead to the formation of deeper and deeper gullies. There are several methods for controlling gully erosion, which can be chosen depending on the materials available.

If it is a small gully, vegetation can be planted in strips across the gully to slow the velocity of water, trap silt, and prevent further erosion.

These techniques are useful to slow runoff and erosion from sloping land, and also to revegetate degraded areas. Areas with high rainfall, steep slopes, and thin soils should use slightly graded bunds / terraces / trenches to allow some drainage.

Bunds have many benefits, including marking the boundaries of farm-holdings, slowing the movement of soil and water, and providing a place for integrating trees into agricultural systems. Here are some tips for using bunds within farmland:

• Cattle should be kept away from the area while establishing saplings, by using livehedge fencing. Cactus, Euphorbia spp, and Agave are useful for a livehedge fence.
• Larger trees can be planted on boundary bunds, and smaller trees which will be harvested more frequently can be planted on internal bunds, which divide one holding into separate sections.

Many NGOs are working along with communities and industries to save rivers in India. The river Ganga is relevant culturally, and its waters have been used extensively by industries and communities. At the same time, industrial and agricultural discharge or waste is being dumped at many stretches.

The Arkavathi programme interlinks communities that have been traditionally independent from one another. The Arkavathi River is one of the principal tributaries of the Cauvery in Karnataka and flows through Rural, Peri - Urban and Urban areas.

The Indian Institute of Technology, Madras, Technology for Sustainable Development and the Ecole Polytechnique Federale de Lausanne EPFL have produced a report titled Integrated Approaches for Sustainable Development in Water Resources Sector.

The Environmental Information Centre & Maharashtra Pollution Control Board has prepared water quality monitoring maps that, at a glance, reflects the various water sources and their locations.