Soil and Water Conservation Technologies :: Watershed Development and Water Harvesting Systems

Soil & Water Conservation Technologies :: Watershed & Water Harvesting

Roof and Terrain Water Harvesting System

Purpose

To recharge the wells (open and tube wells) particularly abandoned wells by a runoff collection system.
Direct on-use of collected water if storage facility is available.

Features

PVC pipe collectors with different diameters collecting from a cluster of buildings in a given area
Normal size of filter bed (2 m x 2 m x 2 m) with stones and pebbles is sufficient for removing sedimentation and other impurities.
Open channels / grased channels under slopy terrains preferred to the pipes for the sack of economy.
Evaporation is negligible.

Cost

Filter bed costs approximately Rs. 3000/-.

4.	Water spreading	:	After flows in streams / gullies are being diverted into adjoining lands by creating small embankments / bunds across the streams. Such diverted water may be pumped or taken by natural gravity so that the excess runoff will fall back in to the same stream after meeting soil moisture requirements of nearby fields.
5.	Individual well recharge	:	Runoff should pass through a filter bed to prevent silting of the well in operation The open well is filled with good sand and gravel around the slotted casing extended in to the open well In bore well casing may be extended up to the ground level The flood water is directed in to the open well filled with sand In the absence of abandoned well a filter bed of 3m square is dug to 2-3m adjoining the pumping well through a 300mm dia. pipe laid at the bottom of the filter bed.

To directly feed depleted aquifers to fresh water from ground surface so that the recharge is fast without any evaporation loss
Coir wrapping as a final protective filter before water enters the well
Constructed by drilling bore hole of 10cm in diameter down to the desired depth
Casing assembly was designed by providing slotted sections against the aquifers
Depth of recharge tube well depends on the present depth of bore wells in the area
The bottom the recharge tube wells is about 30m below the water table in the area
Annular space between the borehole and the pipe is filled with good gravel and developed with compressor until it gives clear water
Flood water filters through the sand filter of 3mx3mx3m size and most of the suspended materials will be filtered out
Second sand filter surrounding the slotted section of the well at the top will prevent the remaining suspended material entering the well.