Context: 

The findings of the first ever water body census, conducted by the Ministry of Jal Shakti, was published recently.

What are water bodies?

• The Ministry of Jal Shakti has defined water bodies as any natural or man-made structures used for storing water for various purposes, such as irrigation, industry, fish farming, domestic use, recreation, religious activities, and groundwater recharge. 
• They are classified as tanks, reservoirs and ponds.
• A structure that collects water from melting ice, streams, springs, rain, or drainage from residential or other areas, or stores water diverted from a stream, nala, or river, is also considered a water body.

Necessity of water body census:

• Important in tackling multiple crises: India is facing a water crisis with groundwater decline, biodiversity loss, and climate change increasing the frequency of floods and droughts. In this context, water bodies are important.
• Ecological significance: 

1. 1. Water bodies buffer against climate variability, holding flood waters for use in dry periods. 
   2. They contribute to food and water security as well as livelihoods by recharging groundwater and providing water for irrigation and livestock. 

• Need of baseline data backed action plans: 

1. 1. Water bodies are increasingly under threat from pollution, encroachment, urbanisation, and drying. If they are to be conserved and managed effectively, we need action plans.
   2. As water bodies are managed by different agencies from State to local to private entities, the data must be uniform and easily accessible.

• Knowledge integration: To actually manage water bodies, contextual and traditional knowledge of communities is needed which are to be integrated with formal data.
• Conservation of smaller water bodies: While data on reservoirs and rivers has been available on the India Water Resources Information System (WRIS), there has been no data on smaller water bodies that are the lifeline of rural India and critical cultural, flood control and recreational spaces in cities.

How was the census conducted?

• Incorporating digital methods: Software for data entry and a mobile app for capturing the location and visuals of the water bodies were developed, and data processing workshops were conducted to train the surveyors in all States and Union territories.
• Objective of the census: To develop a national database with information on the size, purpose, ownership, status, and conditions of water bodies. 
• Coverage: All natural and human made units bounded on all sides for storing water, irrespective of condition or use.
• Inclusion of social data: 

1. 1. The census was built on existing and publicly available satellite derived datasets. 
   2. However, the datasets only include attributes that can be observed from space. 
   3. The water body census extends this to social characteristics including ownership, use and condition.

Observations based on the census data:­

The census allows us to compare spatial and temporal trends of water bodies across the country.

• Size of water body and related issue:  

1. 1. Most water bodies in the country are very small — the vast majority of India’s water bodies are less than one hectare (ha) large. 
   2. This means locating and keeping track of them is likely to remain a challenge. The traditional way to map these water bodies, using satellites, may not work. Ground­-based tracking is a very welcome move.

• Regional patterns of size and ownership: The water bodies show regional patterns that correlate with rainfall.

1. 1. In drier States like Gujarat, Maharashtra, and Rajasthan, water bodies tend to be larger and publicly held. 
   2. In the wetter parts of the country, like Kerala, West Bengal, and States in the northeast, more than three quarters of the water bodies are privately owned. 
   3. In drier States, the water bodies are primarily used for irrigation and groundwater recharge while in wetter States, domestic use and pisciculture dominate. 
   4. Mid Sized water bodies are largely panchayat owned.

• Neglect of rejuvenation: Most water bodies have never been repaired or rejuvenated — several water bodies were classified “not in use”.

Gaps in conducting the census

• Neglect of the ecological functions: The latest water body census does not address any questions about ecological functions of the water bodies and relation with the size and location. The focus of the census was exclusively on human use.
• Incomplete analysis: In classifying water bodies in terms of reasons of abandonment or disuse, the census questionnaire may have left out the most common reasons like eutrophication, sewage pollution, and solid waste dumping.
• Inconsistencies in the classification: The census groups water bodies into five types: Ponds, tanks, lakes, reservoirs, and water conservation schemes. 
  • However, these categories are not mutually exclusive — many tanks that were traditionally used directly for irrigation serve primarily as recharge structures today.
• Non-standardised data across States: Some States like Gujarat do not show any water bodies not being in use, whereas Karnataka reports almost 80% of its water bodies as being in a state of disuse. This suggests differences in interpretation by the enumerators.
• It is unclear if some districts were skipped or if they genuinely had a lower water body density.

Utility in spite of the shortcomings of the census

• This first edition itself provides high-level indications on the way forward by detailing ownership, state of use, and the costs of construction and repair. 
• It points to how and why water bodies must be restored, which agency’s capacities need to be strengthened, where and how much funds are needed, and who will benefit from such efforts. 
• If such censuses are conducted every five or 10 years, over time, they will accurately represent emerging trends and the state of water in the country as a whole.

News Source: The Hindu