Kerala’s water budget, a step towards effective water management

Year 2018. Kerala, in South India, was battered by torrential rain and a massive flood. Year 2019. Kerala was flooded again, though with a magnitude much lesser than the previous year. While the excess of water impacted the state in one season, several areas faced a shortage of water in the summer.

The concepts of water budget and water conservation were floated by a few in 2018 and in 2019. Kerala began recording the availability of water, its consumption, surplus and deficit in 94 gram panchayats of the state.

The trial water budget was conducted at Muttil Panchayat in Wayanad district. The errors and shortcomings from this trial were corrected and loose ends tied up before starting the exercise across the state. On April 17, 2023, Chief Minister Pinarayi Vijayan released the details of the first phase of the water budget.

“The water budget is an excellent tool that will help the panchayats analyse water distribution, and bridge the gaps between demand and supply,” T.N. Seema, co-ordinator of Navakeralam Karma Padhathi (NKP), an initiative to solve socio-economic challenges in the state, told Mongabay-India.

Haritha Keralam Mission, which spearheads the water budget project, is a sub-mission under the NKP focusing on eco-friendy development initiatives in agriculture, water conservation and climate resilient disaster management practices.

“The water budget will aid gram panchayats to design interventions that will solve water shortage if any, plan their projects better, and also help to increase land under agriculture,” Seema explained. Currently, the water budget exercise is limited to rural areas. The availability and demand for water in the urban areas of the state will be calculated in the next phase after the base documents for the gram panchayats are completed.

Unlike the northern states of India that get water from melting of snow, rainfall is the only source of water for Kerala. The annual average rainfall in the state is around 3,000-3,200 mm from the two monsoon seasons and summer rains, but it exhibits significant variations depending on the geography. The northern districts of Kerala receive very little rain after the south-west monsoon and hence require more long-term conservation methods than the southern districts which get both the returning monsoon and the summer rains.

While calculating availability, both surface water and ground water was taken into account in the water budget. Instead of taking data on annual or seasonal rainfall, water availability per ten days was calculated. For this, the total days in a month were divided into 3 units of 10 days each. “The amount of rainfall that we got for the first ten days, second ten days and the third ten days of a month was recorded. This is then compared with a 10-year rainfall data for these particular days and we arrive at average water availability for every ten days of the year,” Abraham Koshy, assistant co-ordinator of the Haritha Keralam Mission, told Mongabay-India.

Maneed panchayat in Ernakulam district, for example, gets an average rainfall of 257.17 mm in the first unit of June, 313.22 in the second and 286.19 in the third. The availability of water is then calculated by a series of formulae that has a number of runoff co-efficients, depending on the landuse pattern. The scientific inputs for the calculation of the availability and requirement of water came from the scientific team at the Centre for Water Resources Development and Managament (CWRDM).

“There were already established co-efficients for water budget calculations, but we tweaked it according to our local requirement,” said C.M Sushanth, retired scientist from CWRDM, who has been associated with the state’s water budget since the planning stage in 2018. “We also accommodated the feedback from the trial run at Muttil to refine the calculations and make them more suitable for our conditions,” he said.

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The distribution of summer rain, south-west monsoon and north-east monsoon, variation in terrain, area under forest, landuse pattern, rainfall infiltration, groundwater recharge, water flowing into the panchayat and water made available outside the panchayat were all considered while calculating the supply and demand. Apart from primary data, secondary data from various government departments like agriculture department, animal husbandry department, groundwater department, irrigation department and various other agencies were also compiled to arrive at the final figures of availability and demand.

The consumption of water for domestic use, irrigation, business, tourism and industrial needs were factored in, while calculating the total demand. “The consumption pattern is peculiar to each panchayat,” said Abraham Koshy. “For example in places like Munnar, there might be more tourists than residents and their consumption pattern will be different from other gram panchayats,” he said. The extent of agriculture, presence of industries and tourism facilities also contributed to the variation in consumption pattern. Even the type of crop cultivated in a particular panchayat and the kind of pets and domesticated animals in a family figured in the calculation of the total demand.

From the ten-day averages thus calculated for every month of the year, it was observed that most of the panchayats had surplus of water except for the drier regions of Palakkad. In Chottanikkara gram panchayat water availability was found to be 21.9 million cubic metre (mcm) and the demand was just 5.58 mcm. In the neighbouring Amballoor panchayat, the availability was 37.17 mcm and the requirement was just 5.19 mcm, giving a surplus of over 31.97 mcm.

“I think this was the best part of the whole exercise – people realising that we are blessed with so much of surplus water,” said Renjini, Ernakulam district co-ordinator of NKP. “Scientific interventions, conservation methods for collecting rainwater, and proper utilisation of summer rain can not only ensure the availability of water throughout the year but we can also extend cultivation into the drier months as well,” she said.

Shaji, associate professor of geology at the University of Kerala echoed his views and said that the water budget has been able to come out with a near accurate domestic draft, or consumption of water for domestic use. “However, we need to have more accurate and updated data on the number of borewells that take out water from deep aquifers. Same is the case with industrial draft,” he said.

Shree Padre, an environmentalist from Kasargod, who is passionate about water conservation, said that water literacy is very important for Kerala. “Our state receives a substantial amount of rainfall. But, you have to make each family accountable for the water they use. Unless every individual takes up the responsibility for water conservation, we might face shortages in the summer months,” he said.

The findings of the water budgets are now being presented before the public in seminars held at block panchayat levels. “Discussions are to be held on the results and analysis, and the recommendations from these seminars will be incorporated into the interventions planned for water conservation of each panchayat,” said Renjini.

While new projects in various sectors are being planned for each panchayat, water budgets are expected to be an effective instrument for ensuring sustainable development.

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Banner image: The wait for tankers to fill in water in Vizhinjam, Kerala. Photo by India Water Portal/Flickr.