Master Plan for artificial Recharge to Groundwater in India

Groundwater is a replenishable resources and hence the availability of groundwater has been taken for granted. The limitation of available surface water resources has put an onus on groundwater to meet the requirement. The groundwater development has gone up manifolds to cater to the demand from agriculture, industry and domestic activities.

The availability of groundwater is always expressed either in relation to its availability or to the annual replenishment, for management purposes. Thus, the term safe yield or sustainable yield is generally used by many developed countries for sustainable development of groundwater. In India, the replenishable groundwater resources are assessed periodically (every three years) and areas are categorized on the basis of Stage of groundwater extraction (safe yield).

The water stress is being felt at different parts of the country owing to the increasing demand resulting from the population explosion. In order to meet the demand, the share of groundwater has increased exponentially, it has far exceeded the natural recharge in many parts of the country, necessitating the both central and State government to take up water conservation through many schemes.

Artificial recharge of groundwater

In order to tackle the twin hazards of de-saturation of aquifer zones and consequent deterioration of ground water quality, there is an urgent need to augment the ground water resources through suitable management interventions. Artificial recharge has now been accepted world-wide as a cost-effective method to augment ground water resources in areas where continued overexploitation without due regard to their recharging options has resulted in various undesirable environmental consequences.

The artificial recharge to ground water aims at augmentation of ground water reservoir by modifying the natural movement of surface water utilizing suitable civil construction techniques. Artificial recharge techniques normally address to the following issues:

• To enhance the sustainability in areas where over-development has depleted the aquifer.
• Conservation and storage of excess surface water for future requirements, since these requirements often change within a season or a period
• To improve the quality of existing ground water through dilution. 

Any executable plan requires the planning to be made in macro level at the first instance and thereafter taken to micro level at the time of execution. 

Master Plan for Artificial Recharge to Groundwater in India (2020)

Master Plan for artificial Recharge to Groundwater in India was prepared by Central Ground Water Board (CGWB) in the year 2013, which was the revision of the conceptual plan made in 2002. In view of the active participation of central and State agencies in water conservation, a need was felt to revise the master plan prepared in 2013 and hence a revised plan was released in 2020.

Scope of the plan

The revised master plan for artificial recharge to groundwater has been made for the whole country at the level of district/Block. The plan is macro plan formulated to work out the feasibility of various structures for the different terrain conditions of the country and respective estimated cost. Hence, the revision of the master plan is like any other master plan prepared for a State or city, which brings out the broad outline of the project and expected investments and for implementation, DPR has to be prepared at an implementable level like any other water supply project or city development project.

The area for artificial recharge has been identified based on post monsoon water level (2018) and long-term post monsoon water trend in most of the States & UTs. However, due to paucity of data and local groundwater issues, additional/different criteria were used in different States/UTs. In the case of NE States, UT of Jammu & Kashmir & UT of Ladakh, the criteria of water scarcity have been used and structures have been suggested to harness the run off generated from the rain. In case of UT of Lakshadweep & UT of Daman & Diu, due to shallow groundwater level, only RTRWH has been suggested.

Salient points

An area of 11.23 Lakh sq.km has been identified for artificial recharge. The scope of artificial recharge depends on the available sub surface space for recharge, water required for recharge and surplus water available for recharge. The volume of space available up to 3m bgl or 5m bgl depending on the criteria adopted in different States multiplied by the specific yield of the aquifers will provide the space available for recharge. Considering an efficiency of 60% or 75% as deemed fit in different States, the water required for artificial recharge has been worked out for each State. The surplus available for recharge after deducting the committed supply has been estimated for each State. The available sub-surface space for artificial recharge 537.349 BCM, while the water required to saturate the aquifer up to 3 to 5m bgl is 716.917 BCM. The surplus source water available for recharge is of the order of 185.092 BCM.

The availability of source water for recharge is not uniform and in many districts in the States of Rajasthan, Punjab, Haryana, Gujarat etc., the source water available is less than the requirement and artificial recharge structures are restricted to the source water availability. The types of structures are decided by the terrain conditions and the number of structures are decided by the source water availability. The different type of structures suitable for different terrain conditions and the use of different terminology for the similar structures in various States have resulted in more than 25 types of structures. In order to group different structures and bring in standardization, the structures were studied and grouped in to 10 groups and in the group “Others” all the uncommon structures are classified. About 75% of structures are towards RTRWH, while 17% is for “Others”, with 3% for RS, 2% of structures are in the category of CD & Gabion structures and 1% under PT category. The unit cost of structure also is found varying within the States for different districts for some States, while in some States/UTs they have assumed a uniform rate. RTRWH accounts for 28% of cost, while “others” category is for 23% of cost and CD & PT account for 19% & RS for 07% of cost.

The total cost for implementation of this revised master plan is Rs 133529.69 Cr, with Rs 96735.45 Cr (72%) for rural areas and Rs 36794.23 Cr (28%) for Urban areas. The implementation approach of artificial recharge projects shall depend on various factors and hence cannot be uniform for the entire country. The major factors in this regard are hydrogeomorphological settings of different areas which vary in different terrain conditions. The watershed approach can be considered to best fit for hard rock terrains, while the basin/sub basin approach is practically suitable for alluvial/sedimentary terrain having large & thick aquifers. Similarly, in hilly terrains, springshed approach can be more scientific & useful in implementation while taking up spring rejuvenation projects. Depending upon the type of existing terrain conditions, the plan for artificial recharge need to be conceptualised by States/UTs while collecting various information/data.

There are many existing schemes and a new scheme is under preparation in respect of comprehensive measures for water conservation in select water stressed districts in the country, resulted out of Budget announcement of the Government, which can cater to the implementation of the revised master plan. No separate funding is required for executing the revised master plan. The different scheme can take the cue from the master plan and construct these structures as per the norms of the schemes. The execution of these structure may take a period of 10 years, if the existing schemes dovetail their activities for convergence towards water conservation.

Owing to the over dependence on groundwater, both State & Central Government Agencies are dovetailing their activities towards water conservation. Consequently, construction of the artificial recharge structures has increased over the years. Further, the construction of structures also depends on the surplus water availability and hence it becomes imperative that geotagging of these structures is made and their functional status monitored. Hence, one Nodal agency is to be identified for each State/UT by the respective States /UTs, which will function as a focal point for the water conservation database and documentations. The master plan for artificial recharge to groundwater has been revised considering the existing data availability.

Considering the technological advancement and parallel scientific studies of NAQUIM being taken up in the country, it is proposed to carry out next revision on a larger scale of 1: 10,000. With the large scale thematic maps, it would be feasible to have micro-level information on area-specific feasible recharge structures & their location, which can be refined during preparation of Detailed Project Reports (DPRs) by the implementing agency in the state. The watershed approach is best fit for hard rock terrains, while the basin/sub basin approach is practically feasible for alluvial/sedimentary terrain & in hilly terrains, springshed approach can be more appropriate for spring rejuvenation projects.

The Master plan covers institutional mechanism, documentation, critical factors in formulation and execution of artificial recharge projects and impact assessment in detail. In the formulation of master plan, use of DRASTIC model, NAQUIM outputs and DPR preparation has been proposed using the GIS technique. The importance of treatment work in upper reaches, prior to implementation of the artificial recharge projects have also been emphasized. Institutional mechanism of District & State level committees for preparation of master plan and DPR, its approval and execution have been outlined to have seamless execution of the activity. Identification of State Level Nodal Agency (SLNA) is very important for the success of this activity. Central Ground Water Board can take up the impact assessment, however, the updation of database on artificial recharge by State agencies is mandatory for talking up impact assessment studies.  

To access the complete report, click here.

Source : Central Ground Water Board, Department of Water Resources, River Development & Ganga Rejuvenation, Ministry of Jal Shakti, Government of India