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Raising
underground water column
In many areas due to drought
conditions the underground water column drops, resulting in dried irrigation
wells or much higher water pumping cost with more consumption of energy
translating higher bills. The simplest way to raise water column is to give rain
water a direct access to water column because it takes months for rain water to
seep through the soil layer ( 20-60 feet) until it reaches to the water column.
The solution is to dig few open wells with safety guards to protect humans and
pets at lower elevations (depressions) so that the drainage of rain water gets a
direct access to those open wells to feed the underground column directly. Since
water column has a sandy vain structure, the direct access will raise the water
column almost instantly without spilling out elsewhere.
Few
articles from the internet
Paar system:
Paar is
a common water harvesting practice in the western Rajasthan region. It is a
common place where the rainwater flows from the agar (catchment) and in the
process percolates into the sandy soil. In order to access the rajani pani
(percolated water) kuis or beris are dug in the agor (storage area). Kuis or
beris are normally 5 metres (m) to 12 m deep. The structure was constructed
through traditional masonary technology. Normally six to ten of them are
constructed in a paar. However depending on the size of the paar the numbers of
kuis or beris are decided. Bhatti mentions that there are paars in Jaisalmer
district where there are more than 20 kuis are in operation. This is the most
predominant form of rainwater harvesting in the region. Rainwater harvested
through PAAR technique is known as Patali paani.
Talab / Bandhis
Talabs are
reservoirs. They may be natural, such as the ponds (pokhariyan) at
Tikamgarh in the Bundelkhand region. They can be human-made, such the lakes in
Udaipur. A reservoir area of less than five bighas is called a talai;
a medium sized lake is called a bandhi or talab; bigger lakes are
called sagar or samand. The pokhariyan serve irrigation and
drinking purposes. When the water in these reserviors dries up just a few days
after the monsoon, the pond beds are cultivated with rice.
Saza Kuva
An open well with multiple owners (saza = partner), saza kuva is
the most important source of irrigation in the Aravalli hills in Mewar, eastern
Rajasthan. The soil dug out to make the well pit is used to construct a huge
circular foundation or an elevated platform sloping away from the well. The
first is built to accomodate the rehat, a traditional water lifting
device; the sloping platform is for the chada, in which buffaloes are
used to lift water. Saza kuva construction is generally taken up by a
group of farmers with adjacent landholdings; a harva, a man with special skills
in groundwater detection, helps fix the site.
Johad
Johads are small
earthen check dams that capture and conserve rainwater, improving percolation
and groundwater recharge. Starting 1984, the last sixteen years have seen the
revival of some 3000 johads spread across more than 650 villages in Alwar
district, Rajasthan. This has resulted in a general rise of the groundwater
level by almost 6 metres and a 33 percent increase in the forest cover in the
area. Five rivers that used to go dry immediately following the monsoon have now
become perennial, such as the River Arvari, has come alive.
Pat
Bhitada village , Jhabua district of Madhya pradesh developed the unique pat
system. This system was devised according to the peculiarities of the terrain to
divert water from swift-flowing hill streams into irrigation channels called
pats.
The diversion bunds
across the stream are made by piling up stones and then lining them with teak
leaves and mud to make them leakproof. The pat channel has to negotiate small
nullahs that join the stream off and on, and also sheer cliffs before reaching
the fields. These sections invariably get washed away during the monsoons. Stone
aqueducts have to be built to span the intervening nullahs.
The villagers irrigate their fields by turns. The channel requires constant
maintenance and it is the duty of the family irrigating the fields on a
particular day to take care of the pat on that particular day. It takes about
two weeks to get the pat flowing and the winter crop is sown in early
November.
Naada / Bandha
Naada/bandha are
found in the Mewar region of the Thar desert. It is a stone check dam,
constructed across a stream or gully, to capture monsoon runoff on a stretch of
land. Submerged in water, the land becomes fertile as silt deposits on it and
the soil retains substantial amounts of water.
Rapat
A rapat is a
percolation tank, with a bund to impound rainwater flowing through a watershed
and a waste weir to dispose of the surplus flow. If the height of the structure
is small, the bund may be built of masonary, otherwise earth is used. Rajasthan
rapats, being small, are all masonry structures. Rapats and percolation tanks do
not directly irrigate land, but recharges well within a distance of 3-5 km
downstream. Silting is a serious problem with small rapats and the estimated
life of a rapat varies from 5 to 20 years.
Chandela Tank
These tanks were
constructed by stopping the flow of water in rivulets flowing between hills by
erecting massive earthen embankments, having width of 60m or more. These hills
with long stretches of quartz reefs running underneath them, acted as natural
ground water barrier helping to trap water between the ridges. The earthen
embankments were supported on both sides with walls of coarse stones, forming a
series of stone steps. These tanks are made up of lime and mortar and this is
the reason why these tanks survived even after thousand years but the only
problem, which these tanks are facing, is siltation of tank beds. Chandela tanks
usually had a convex curvature somewhere in the middle of the embankment; many
older and smaller tanks were constructed near the human settlement or near the
slopes of a cluster of hills. These tanks served to satisfy the drinking water
needs of villagers and
cattle.
Bundela Tank
These tanks are
bigger in size as compared to Chandela tanks. These tanks had solidly
constructed steps leading to water in the tank; But these structures had
chabootaras, pavillions and royal orchards designed to show off the glory of the
king who built them. But these tanks are not as cost effective and simple as
Chandela tanks. These tanks were constructed to meet the growing water demands
in the area, maintenance of these tanks was done by the person employed by the
king but in case of smaller tanks villagers collectively removed silt and repair
embankment.
Kunds / Kundis
A kund or kundi looks like an upturned cup nestling in a saucer.
These structures harvest rainwater for drinking, and dot the sandier tracts of
the Thar Desert in western Rajasthan and some areas in Gujarat.
Essentially a circular underground well, kunds have a saucer-shaped
catchment area that gently slopes towards the centre where the well is situated.
A wire mesh across water-inlets prevents debris from falling into the well-pit.
The sides of the well-pit are covered with (disinfectant) lime and ash. Most
pits have a dome-shaped cover, or at least a lid, to protect the water. If need
be, water can be drawn out with a bucket. The depth and diameter of kunds
depend on their use (drinking, or domestic water requirements). They can be
owned by only those with money to invest and land to construct it. Thus for the
poor, large public kunds have to be
built.
Kuis / Beris
Found in western Rajasthan, these are 10-12 m deep pits dug near tanks to
collect the seepage. Kuis can also be used to harvest rainwater in areas
with meagre rainfall.
The mouth of the pit is usually made very narrow. This prevents the collected
water from evaporating. The pit gets wider as it burrows underunder the ground,
so that water can seep in into a large surface area. The openings of these
entirely kuchcha (earthen) structures are generally covered with planks
of wood, or put under lock and key. The water is used sparingly, as a last
resource in crisis situations.
Magga Ram Suthar, of village Pithla in Jaisalmer district in Rajasthan, is an
engineer skilled in making kuis/beris.
Baoris / Bers
Baoris or bers
are community wells, found in Rajasthan, that are used mainly for drinking.
Most of them are very old and were built by banjaras (mobile trading
communities) for their drinking water needs. They can hold water for a long time
because of almost negligible water evaporation.
Jhalaras
Jhalaras were
human-made tanks, found in Rajasthan and Gujarat, essentially meant for
community use and for religious rites. Often rectangular in design, jhalaras
have steps on three or four sides.
Jhalars areground water bodies which are built to ensure easy & regular supply
of water to the surrounding areas .
the jhalars are rectangular in shape with steps on three or even on all the four
sides of the tank . the steps are built on a series of levels .
The jhalaras collect subterranean seepage of a talab or a lake located upstream
.
The water from these jhalaras was not used for drinking but for only community
bathing and religious rites .
Jhodhpur city has eight jhalaras two of which are inside the town & six are
found outside the city .
The oldest jhalara is the mahamandir jhalara which dates back to 1660 AD
Nadis
Nadis are village
ponds, found near Jodhpur in Rajasthan. They are used for storing waterfrom an
adjoining natural catchment during the rainy season. The site was selected by
the villagers based on an available natural catchments and its water yield
potential. Water availability from nadi would range from two months to a year
after the rains. They are dune areas range from 1.5 to 4.0 metres and those in
sandy plains varied from 3 to 12 metres. The location of the nadi had a strong
bearing on its storage capacity due to the related catchment and runoff
characteristics.
Tobas
Tobas is the local
name given to a ground depression with a natural catchment area. A hard plot of
land with low porosity, consisting of a depression and a natural catchment area
was selected for the construction of tobas.
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