Monday, 27 April 2020

Johads, an age-old simple traditional water structures that can improve and revitalize ground water to a great extent

The government both at center and state levels give far  more importance  to building large gravity dams and digging of canals to access water year round - a legacy left behind by the colonialists than to age-old traditional water storage structures like Johads that have played a vital role in semi-arid regions of western India. There are around 5000 reservoirs and dams in India  to meet the water demand of our people and industries. The water scenario is changing in the last several decades and in India the monsoons do not produce enough rain every year. Another grave unchecked problem  is in many states excess rain  water goes waste as runoff in the absence of check dams at certain  vantage places. So are the rivers that are  in spate. Since 1980s the state governments have begun to turn their attention to the revival of Johads, etc to conserve water. 
Johads, India
Johad, water storage, India.
 Johad, also known as a pokhar or a percolation pond, is a small  earthen check dam  that captures and conserve rainwater. The advantage is depending on the soil, rock formation and  their porosity and permeability, it promotes downward percolation of stored water  and recharges ground water. It is commonly  community-owned traditional harvested rainwater storage wetland primarily  used for  storage of water resources for future use. Johad water harvesting  system is widely used in states like Haryana, Rajasthan, Punjab, and western Uttar Pradesh of North India.  The collected/stored  water is available year round.  Johads help recharge ground water in the nearby wells.  Some johads also have bricked or stones masonry and cemented ghat (series of steps and/or ramp). They are cheap and productive. 

A johad does  have the following  advantages:  01. It checks the run off rain water, 02. It holds the water in one place and promotes downward percolation through the soil, 03. It recharges the acquirers  (vast sand formations that hold water) below the ground and can reach roughly one kilometre around, 04. This way nearby wells  get enough water that can meet the water needs in the summer.   05. With sufficient water, irrigation is possible and the villagers can raise wheat, mustard and beans, 06. The crescent shaped check dam has a dual function - at the surface it holds water for the livestock and right below like an iceberg  the soil-filtered, percolated and stored water is safely protected  from  loss  due to evaporation.  

The beneficiaries of ancient water structures are not only humans, but also  seasonal migrant birds, as well as wildlife animals  from near by jungle/bani.  Johads are put to use by the State fisheries departments   promotion  of commercial fisheries.  Johads  are  set in such a way, they are often surrounded by embankment, with water well and trees around them.  They go  by different names  - sarovar, taal and talab (roughly equal to ponds or lakes). In  Alwar  and other districts of Rajasthan  the rain fall is less than 600 mm /year and the water can be unpleasant to drink. Being arid to semi arid region, the SW Monsoon in June to August does not bring in enough water. Thanks to Dr. Rajendra Prasad and the voluntary organization  Tarun Bharat Sangh, they revived  and rejuvenated more than 4500 johads in Rajasthan that resulted in the manifold  increase of ground water storage. The state of Haryana's Water body Management Board manages more than 14000 ponds besides development of 60 lakes in  Delhi NCR to cater to the water needs of the people.
There are many types of johads though the main purpose is to channel the rain water to the dug-out area for storage. The building of  a simple mud and rubble barrier check dam is a good bet and cost-effective. It can be built on a sloping terrain with  a high embankment on the three sides while the fourth side is left open for the rainwater to enter. Such small catchment areas can  trap  and conserve rainwater to a considerable extent, improving  percolation and groundwater recharge.  The rainwater storage tank (johad) at the Mandalwas village (India) which has a 100 metre embankment. One of the biggest such johads in the region, with a capacity of one thousand million cubic feet capacity, it has promoted  food and water security in the village.

The central government  with a view to solving future water scarcity in 2019  gave due importance to Atal Bhujal Yojana (Atal groundwater scheme). It is a 5 years (2020-21 to 2024-25)  water project and the estimated cost is INR 6 billion (US$85 million) and it will be done at the village panchayat level  to encourage revival of wetland  and recharge of the ground water sources. For this purpose chosen are  8,350 water-stressed villages across 7 states, including Haryana, Rajasthan, Gujarat, Madhya Pradesh, Uttar Pradesh, Karnataka, and Maharashtra.
Design of water johads. Source: Anupma Sharma, National Inst. of Hydrology.
  Water johads are  a simple way to conserve water and in expensive.  These low cost low-cost structures do not require large  equipment or expensive materials to build. All you need is cooperation from the local community who can supply able bodied persons to get involved in the work. After digging a pit, the  workers build a semicircular mud barrier  with the excavated earth.  A stone drain is added to allow the  excess water to seep into the ground, or connecting it with johads nearby. Thus johad will  effectively capture runoff from monsoon floods and allow it to slowly percolate into the water table during the dry months. When you build many johads in one region, after the rain fall, it will have a cumulative effect on the natural ground water storage  system that will be recharged in many places where  there is a johad.  In addition, it has been shown that the water stored in the aquifers does not draw away by  communities downstream. 

It must be borne in mind that water johads are terrain -specific technologies and cannot necessarily be replicated to other geographical locations or climates. What is appropriate  in one location may be unfit in another region. Knowledge of geomorphology of the region and terrain contour  is the foremost criterion. Johads commonly requite  steady sloping land—where each one  can feed water into another downstream in a  a rainy season and  the recharged reservoirs serve well during the dry months. 
Johads are  far more cost-effective than high-tech dams are; the latter may  cost  a huge sum of money  besides, displacing  the lives of a million plus people in the catchment areas. Such simple johads do not get the serious attention of the state governments for regular maintenance.   The village communities come together and develop skills in  water management and periodically maintain the Johads in use in their respective areas. This way villagers can reduce the water stress in their region to a great extent. Johads can revive and rejuvenate the dying aquifers  in that region.