Artificial recharge and conservation of ground water has assumed high
importance in augmenting the fast depleting resources needed for agriculture, industries
and drinking purposes. NCR has taken up several recharge and conservation projects in
different hydrogeological terrains of Madhya Pradesh to demonstrate the efficacy of
various recharge structures in making the public aware of the benefits of such works based
on sound scientific inputs. It is however, imperative to have full understanding of the
hydrogeology for planning any groundwater conservation and artificial recharge scheme as
the occurrence movement and availability of ground water in M.P. is controlled by its
widely heterogeneous nature of rocks. Madhya Pradesh state has taken a lead in integrated
watershed management under Rajiv Gandhi Watershed Mission with commendable input of
"People’s participation". However , in such mass movement by providing
general and technical assistance to state Govt. in execution of artificial recharge
schemes at selected sites to provide models which can be replicated elsewhere. The salient
features of these projects are as follows:
Roof top rain water
harvesting, PHE colony, Musakhedi, Indore Madhya Pradesh.
Indore city is highly
urbanized and developed with a high percentage of paved area resulting in reduction of
natural ground water recharge and increased rainfall run off. Decline of water levels and
depletion of yield in tubewells and dugwells has become a problem of vital concern. The
cause of this problem has been over-drawal of ground water. Indore town is occupied by
Deccan Trap basaltic lava and a succession of five basaltic flows has been mapped.
Weathered/vesicular/fractured jointed basalts form aquifers in the area. Hydrogeology of
the area dictates the necessity of recharge wells which can directly augment the available
ground water at deeper level. In the PHED colony, Musakhedi, office buildings, having
sloping roofs, covering an area of 2710 sq. m were selected for roof top rainwater
harvesting. The total quantum of water available on rooftop works out to be 2520 m3. Out
of this the water available for recharge is 2142 m3. This roof top rainfall has been
diverted to a recharge well through channels after being passed through a filtration
chamber. A piezometer of 60 m depth has been drilled in the campus and installed with a
digital water level reorder to assess the impact of roof top rain water harvesting.
The hydrograph of the
DWLR was carrelated with the rainfall data and it was found that there was a peak in the
hydrograph corresponding to the rainfall. The water level had risen from 13.0 bmp to 9.25
mbmp in mid. September after which there is a gradual decline. This has effectively
demonstrated the efficacy of rooftop rainfall harvesting in urban areas underlain by
basaltic terrain.
Rooftop rain water
harvesting in Dewas city, Dewas district Madhya Pradesh
Dewas city located in the
Malwa region of Madhya Pradesh is one of the highly water scarce areas of M.P. water was
even brought by special water trains in the past. A low cost filter as per specification
of CHPHEED, New Delhi to filter the rooftop rain water before being recharged to the
aquifer was developed by Bhujal Samvardhan Mission, Dewas under technical inputs from
Central Ground Water Board, Bhopal. In Dewas city and surrounding areas, 1000 houses
having service tubewells were selected where rooftop rain all was diverted to the tubewell
via a drainage pipe after being passed through the online filter. A digital water level
recorder installed in the premises of the district court Dewas revealed that there was
instantaneous recharge to ground water after the rains. It has been established that there
has also been a marked increase in the discharge of tubewells and improvement in quality
of water being obtained from tubewells utilizing rooftop rain water harvesting.
Construction of
recharge shafts in Dewas district:
Dewas district has many
village tanks which overflow during monsoon but dugwells located nearby record deep water
levels. This is because the heavy siltation in tank bed does not allow the surface water
to percolated and recharge the shallow aquifer tapped in dugwells. At some places when the
tanks were desilted during monsoon no surface storage could be created as it acted as a
very good percolation tank. However keeping in view the need of water in village tanks for
Nistar purpose it was felt that artificial recharge technique should be such that in
addition to ground water augmentation some water was available to villagers in the form of
surface water. This situation was considered ideal for construction of recharge shafts in
village shafts in village tanks. To demonstrate the efficacy of such structures CGWB
constructed 14 recharge shafts in five tanks of the district. The water levels in the
nearby dugwells have registered a rise in the water levels after the monsoon.
Tumar watershed,
Mandsaur district, Madhya Pradesh:
Tumar watershed falling
mostly in the Mandsaur block of Mandsaur district is an area decline of water levels is
taking place due to over exploitation of groundwater resources. Studies by NCR indicate
that there has been a decline of ground water levels ranging from 1.25 m to 4.60 m with an
average decline of 3 m between 1979 and 1998. The area also has saline ground water deeper
levels due to which water suitable for irrigation is available in shallow zones only. It
was thus proposed to take up a watershed for pilot project studies in the watershed. In
this watershed one percolation tank two check dams, one cement plug and 19 gabion
structures were constructed for conservation and recharge to ground water aquifer. It was
estimated that these structures would help in conserving and recharging about 700000 cubic
meter of ground water and would bring an additional area of about 225 hectares under
assured irrigation.
Artificial recharge
structures in Rajgarh district:
In the village Barwa
Kalan and surrounding areas of Ajnar sub basin tehsil Biaora, district Rajgarh underlain
by basalts overlain by alluvium there is heavy outflow of ground water to the river in the
form of base flow from the area. To conserve this base flow, so that additional ground
water could be available for irrigation and other uses during the lean season, a
subsurface dykes were constructed across the river Ajnarnear Barwa Kalan village. The
catchment area was 7.2 km2 and the available water for recharging was estimated to be 0.9
MCM. Due to the construction of the subsurface dykes, water levels in the dugwells
registered a rise in the range of 0.80 to 3.80 m, while in the hand pumps the rise was in
the range of 6.0 to 12.0 m. Due to the rise in water levels and the increased water
columns, the yield of dugwells showed a marked increase of 50-100%. Wells which became dry
by January end can now sustain pumping till April end.
Artificial recharge
studies in Londhri watershed, Dewas district M.P.:
In Londhri watershed
lying in Sonkutch tehsil of Dewas district also, there is heavy outflow of ground water to
the Londhri river in the form of base flow. To conserve this base flow , so that
additional ground water could be available for irrigation and other uses during the lean
season subsurface dyke, a boulder check dam and a gabion structure was constructed across
the Londhri river. The watershed is underlain by basaltic lava flows overlain by alluvial
deposits. Due to the construction of the subsurface dyke and related structures, the water
levels in the area have shown a rising trend. The water level in the existing tubewells
increased by 0.30-2.00 and the dugwells which were becoming dry by January end have water
column till the end of April.
Construction of
sub-surface dykes at Dhobighat and Chhintaharan in Utawali watershed block Burhanpur
district Khandwa, M.P.
Dhobighat and Chinta
Hararan streams are parts of Utavali watershed located in Burhanpur block of Khandwa
district M.P. In this watershed streams are generally parallel in nature carrying
tremendous amount of monsoon run off within short span of time due to high gradient of the
area. The depth of phreatic aquifer consisting of granular zone is restricted only down to
36 mbgl. followed by thick clayey bed preventing further downwards percolation of ground
water. At places in the streams section, the depth of this marker bed is tapering against
the granular zone forming springs in alluvial area. During non monsoon period, these
springs are seen oozing out in the course of streams as base flow of ground water within
the alluvial area and finally disappear at the contact of Alluvium and Deccan Trap,
draining into Tapi river through vesicular/fractured basalts. The stream discharge was
recorded to be about 10-12 lps at Dhobighat and Chhinta Haran during the month of
February-March. To prevent the draining of alluvial aquifers, subsurface barriers were
constructed across the streams in its lower section and before the contact of alluvium and
Deccan Trap. The subsurface dykes effectively arrested the out flows of ground water from
the area and helped in conserving ground water outflow. Due to construction of subsurface
dyke, the base flow at Dhobighat has been completely stopped while at Chhintaharan the
rate of base flow has been reduced to on fourth of its earlier flow. The ground water
levels have also registered a rise in the upstream of the dyke.
Construction of
subsurface dyke and related structures at Walmi Farm, Bhopal
The purpose of
construction of the subsurface dyke was to conserve the subsurface base flow of ground
water below the embankment of spill channel of Kaliasote reservoir adjoining the rain
water harvesting tank built across a small hilly nala. The water of the tank was
percolating out at the rate of 10 to 12 cm/day to the spill channel as vesicular basalt
formed the tank bed. The tank was built for irrigation purposes and it was not realized at
that time that the weathered vesicular basalt forming purpose and it was not realized at
that time that the weathered vesicular basalt forming permeable bed in reservoir area
would drain off the stored water into the adjacent spill channel of Kaliasote reservoir.
Several monsoon seasons passed but the water harvesting tank could not be utilized for
irrigation as water stored in the tank did not last even for one month after the monsoons.
A study was conducted by the Central Ground Water Board to solve this problem and it was
conducted that a sub surface dyke on the lower end of the water harvesting tank could
effectively prevent the subsurface outflow of ground water into spill channel. Deccan Trap
basaltic lava flows of the "Malwa Traps" overlying the Upper Bhander (Vindhyan)
sandstone occupy WALMI Farm area.
The subsurface dyke was
constructed in ‘L’ shape, with long side with about 40 m length at the lower end
of the tank, along the width of the tank and the short side with about 20 m length
continuing parallel to the tank. In order to increase the life of the tank and maintain
longer inflow (surface and subsurface) to ensure exploitation of water for longer period,
about 460 m length of contour trenches (continuous trenches 214 m and staggered trenches
246 m) have been constructed in the catchment area of water harvesting tank. For
construction of nalla bund, puddle clay was embedded between two rows of A.C. sheets along
the cross section of nala and A.C. sheets supported by sand filled bag with non expensive
material ie. sand. These bags were covered by stone pitching with cement grouting. Two
piezometers have been constructed one upstream of the subsurface dyke, down to a depth of
8.25 mbgl and another downstream of the subsurface dyke down to a depth of 6.0 mbgl. Based
on the above studies, it has been inferred that the structure has marginally increased the
water retention period of the tank has shown commendable improvement during the monsoon
following the construction of the sub surface dyke. The average rate of water depletion
has reduced from 10 cm/day to about 6 cm/day. The nala bund has retained about 500 cum of
water with less than 150 mm rainfall for more than 12 days after it stopped raining
recharging the phreatic aquifer. The construction of subsurface dyke contour trenches and
sand bag type nala bund has helped in water conservation groundwater recharge as well as
increase in soil moisture around the water harvesting tank in the WALMI Farm, which is
beneficial for the farm crops/horticulture plantation.
Construction of
subsurface dykes at Chhoti Kasrawad, block Kasrawad, district Khargone
The area is occupied by
Deccan Traps consisting of vesicular weathered fractured and massive basalts with
intertrappean red bole bed. It was observed that ground water seepage, as base flow in
nallas in appreciable due to steep gradient. Ground water level in the area decline very
fast after monsoon and availability of ground water tapped by means of shallow dugwells is
not adequate for irrigation. It was thus planned that ground water can be effectively
stored as subsurface storage in the unsaturated zone/vadose zone by obstructing the base
flow by construction of subsurface dyke. Due to construction of dykes, the base flow was
been reduced substantially. As a consequence ground water levels have risen. The impact is
also reflected in the increase of command area of dugwells in the vicinity of these dykes
as reported by the farmers of the area.
The recharge and
conservation projects as discussed above have been taken up in diverse hydrogeological
terrain of Madhya Pradesh and have demonstrated the efficacy of various recharge
structures that can be constructed keeping in view the local conditions and requirements.
These recharge measures have enhanced the sustainable yield in the areas where over
development has depleted the aquifer, resulted in conservation and storage of excess
surface water for future requirements, since these requirements often change within a
season of period improved the quality of existing ground water by dilution, reduced the
excessive base flow going out of the ground water regime, demonstrated the efficacy of
online domestic filter etc. The techniques adopted are by and large cost effective and can
be replicated by various agencies as well as by the local populace. These measures, if
taken up on a large scale through out the state, may also ultimately lead to drought
proofing of the state.
Perspective Plan for
Artificial Recharge in Madhya Pradesh:
The main artificial
recharge structures proposed are given below along with the estimated cost.
| S.No. |
Structure |
Number |
Cost
(Rs. Crore) |
Unit Cost
(in lakhs) |
| 1 |
Percolation tanks |
5302 |
1060.4 |
20 |
| 2 |
Nala bunds |
20198 |
202.00 |
1 |
| 3 |
Recharge shafts and gravity
head recharge wells |
23181 |
579.5 |
2.5 |
| 4 |
Gully plugs/Contour
bunds/Gabion structures |
69598 |
69.6 |
0.1 |
| 5 |
Total cost |
|
1891.5 |
|
| 6 |
Cost of rooftop rainwater
harvesting in Urban area |
|
244.18 |
0.1 |
| 7 |
Grand total |
|
2135.68 |
|
Apart from
this, there are 19 standard Urban areas in Madhya Pradesh that cover an area of 1321.05
Sq. km. in which a total roof area of about 12.21 Sq.km. is available to collect the roof
top rainfall. The total available water from rooftop rainwater harvesting works out to
12.04 MCM. The average expenditure on providing the necessary arrangements through pipe
fittings, filter etc. to divert the roof water to the existing groundwater structure
(tubewell/dugwell) has been considered as Rs. 10,000/- per house. The total cost for
rooftop rainwater harvesting in the 19 cities of Madhya Pradesh declared as standard Urban
areas works out to 244.18 crores.
MASTER PLAN FOR
ARTIFICIAL RECHARGE TO
GROUND WATER IN MADHYA PRADESH AT A GLANCE
| 1. |
Area identified for
Artificial Recharge |
36245 MCM |
| 2. |
Total volume of unsaturated
zone |
107024 MCM |
| 3. |
Total sub surface storage
potential |
2855.18 MCM |
| 4. |
Requirement of water |
3797.39 MCM |
| 5. |
Total availability of source
water |
10783.29 MCM |
| 6. |
Volume of water to be
recharged |
2618.02 MCM |
| 7. |
Total number of structures
proposed i) In Rural areas |
118270 |
| |
ii) In urban areas (Roof
top rain water harvesting) |
244176 |
| |
Total |
362446 |
| 8. |
Estimated cost (i) In Rural
areas |
Rs. 1911.5 crores |
| |
(ii) In Urban areas |
Rs. 244.18 crores |
| |
Total |
Rs. 2155.59 crores |
|
GROUND WATER CONSERVATION AND RECHARGE
