Clean roofs, full tanks

Have you been seeking a solution for your drying well? Well, the answer might be found closer than you think — right on your roof!

How can a roof prevent wells from drying? Just ask Arunkumar Joshi of Sirsi, Ganapathy Bhat Yekkadka of Perlampady in Dakshina Kannada or Ajit Prasad Jain of Dharmasthala.

Four years ago, Ajit was very worried. It was summer. The water level in his well had gone down to one foot. He was dependent on the panchayat water supply. That very year, taking the suggestions of others, he directed water collected on his roof to the well.

His ‘do-it-yourself’ arrangement is very simple. He has tied a mesh to the end of the pipes directing the roof water into the well. Once in a while, he opens the mesh and cleans it.

This year, despite severe drought conditions, his well has two-and-a-half feet of water. Every day, he pumps water from the tank for about 45 minutes to irrigate his flowering plants and arecanut trees. By the next day, the water is restored almost to the same level.

Be it in urban or rural areas, rainwater collected from roofs has the potential to maintain water levels in wells.

Take the example of the coastal districts of Udupi and DK. They have an annual rainfall of 3,600 mm. Even smaller houses get more rainwater on their roof each year than their total annual requirement.

“In average-sized houses, we generally divert rainwater from about 100 sq metres roof area. In still smaller houses, we may only have about 60 square metres of roof to catch rain. Despite this, in about 20% of the cases, completely dry wells have come back to life in a year or two. There is a 90% success rate in other cases. Overall, the owners get considerably more water,” says Sunny Asariparambil, a rainwater harvesting expert. He runs Susthira, an NGO working in the field for 18 years. Based in Thaliparamb in Kannur district, the organisation has worked on roof water diversion projects for about 25,000 wells.

Efforts over the years

Over two decades ago, in 2001, wells in Hulemalagi Onikeri in Sirsi taluk registered an all time low level of water. They were set to dry up. The whole community rose to action and started watershed development activities. About 35 to 40 houses participated in a weekly ‘shramadan’ (donation of labour) and dug the trenches. In about five years, they worked on around 400 acres. Later on, they received some government aid, with which they dug larger structures like percolation ponds.

“Our normal rainfall is 150 cm,” says Ganapathy Dattatreya Hegde, one of the forerunners of the community’s rainwater harvesting mission, “but in 2015 and 2016, we got very little rain, 85 cm and 82 cm. Despite this, none of our wells dried.” Even this year, the wells have 4 to 8 ft of water, he adds.

In 2013, similar efforts came to the neighbouring Bengli village when Gautham Bengle, a software engineer, spent Rs 5 to 6 lakh from his own pocket on a massive rain-catching project. They dug trenches and created a few percolation ponds at strategic places. About 300 to 400 acres of betta land was treated this way.

Owing to this work, the open wells in the area that were almost drying up now have five to six feet of water, despite the last two years of scarce rainfall.

The principle followed in both places is the same: Make running rainwater stop and sink. To enable this, contour trenches are dug, starting from ridges down to the valleys. Wherever run-off is heavy, percolation ponds are set up. Local trees are planted in treated barren lands. This strategy is aimed at protecting and growing the green canopy to catch rain and take over the work of trenches and ponds.

Alternative methods

In 2004, Udayashankar Adka did not have enough water to irrigate his arecanut gardens. The dilemma in the family was whether to dig a borewell or construct a ‘katta.’ A katta is a temporary check dam, constructed across a river to store water.

After discussions, they opted to construct a katta. After spending a day and Rs 12,000, the katta was functional. It raised the water level upto a kilometre on its upstream. This was in Ivathoklu village, 5 km away from Panja in Dakshina Kannada.

From the following year, many neighbours came forward to share the expenditure. Now, all of them get sufficient water till summer rains arrive in April. This decade-old participatory custom of constructing a katta benefits about 10 to 12 families.

Udayashankar recalls, “Before the katta was constructed, each family used to commission polklines to dig a pond on the river bed. The total expenditure was around Rs 40,000. Now, thanks to the katta, all families have sufficient drinking water in their wells too. If not for this, many borewells would have been dug in our region.”

While the check dam raises the water level in all the water bodies in the neighbourhood, a borewell depletes the groundwater, causing concerns among neighbours as to whether their water bodies will eventually dry up.

Sudhir Kumar Perdoor who lives near Manipal, has an interesting tale to share. A software engineer and farmer, he has travelled extensively. Last year, he worked on constructing an innovative katta. Earlier, while in Europe, he had studied ‘weirs’ or low-head dams and constructed a similar one here at a cost of Rs 2 lakh.

Sudhir points out, “Our river has no water now in the upstream. But our downstream has running water. The water flowing in the river right now solely comes from the dam’s overflow.” He adds that this type of dam is commonly used in Europe, to ensure the consistent flow of water in the river during summer.