Find out how the institute became self sufficient in water by following simple conservation techniques
Soon after IIM-Kozhikode started operating in 1996, from temporary premises in the city, it started planning for its own campus. Two hillocks making up 96 acres in the outskirts of Kozhikode had been allocated but there was one major problem. This area did not have any sustainable water source nor was it served by piped water connections. Something drastic had to be done to meet the daily water needs of the institution, estimated at over 300000 litres for about 1500 residents. After much deliberation, it was decided to harvest rainwater. Rainwater harvesting is cost effective, eco-friendly and sustainable. What better solution for a basic necessity, says Professor Debashis Chatterjee, Director, IIM-Kozhikode.
Preparing to harvest rainwater There were some basic factors that needed to be kept in mind to make this project successful:
CREATION OF HARVESTING POND: Since IIM-K had no natural water source large enough to hold copious rainfall, a harvesting pond needed to be created.
SOIL CONSERVATION: The undulating terrain of the campus presented huge soil erosion challenges. On the one hand, the rainwater runoff storage was sought to be maximised. On the other, soil erosion posed major hindrances, reflects Professor Chatterjee.
WATER GULLIES: The runoff had to be channeled in the direction of the water store. These drains had to be kept free of eroded soil.
FUTURISTIC SOLUTION: Keeping in mind the future expansion of the campus and hence, of its water needs, a replicable system was desirable.
Innovative solutions All the challenges were met by creative interventions.
CATCHMENT AREA AND EARTHEN PROJECTIONS:
The campus buildings are situated at the top of the hillocks. Rainfall on rooftops, hillsides and embankments is channelled through pipes and drains to a five-acre catchment area at the foot of the hillocks before the main storage pond. A small seasonal rainwater-fed source was excavated to create a storage pond of 55000 cubic metre capacity. Feeding the runoff to the catchment, instead of directly to the main pond, helps recharge the water table. An arecanut garden, a thick layer of weed wines and an old pond make up the catchment area. In particular, the old pond helps accelerates the rate of water percolation through which much of the runoff reaches the storage pond. To give rainwater more time to percolate, strategically installed earthen projections lessen the overflow from the catchment. What overflows is channelled through a concrete-lined canal. Water from the storage pond is treated and pumped to an overhead tank at the hilltop, from where it is distributed.
SOIL CONSERVATION AND CONGO-SIGNAL GRASS:
One of the biggest challenges of this solution was soil erosion from the steep slopes. Soil deposited in the catchment would reduce percolation. To stabilise the soil, coconut geo-textile was sourced from the Coir Board. Altogether, 35000 square meters of such woven fabric that can pass water but hold back soil, was laid on the slopes and planted with seeds of Congo-signal (tall) grass. Gradually, the seeds took root and grew to become a thick vegetative cover while the biological geo-textile decayed. To cut the velocity of the runoff and prevent soil deposit in the older gullies acting as storm-water drains, those were lined with grass. A few drains constructed afresh were also lined with thick grass.
TREATING SEWAGE WATER FOR IRRIGATION:
To ensure enough water for irrigating the plantation, sewage water is treated. This yields an output of roughly 50000 litres of treated water every day.
TREE PLANTATION FOR BEATIFICATION AND CONSERVATION:
Tree planting is the most recent initiative to cut soil erosion, recharge groundwater and beautify the campus. Our students are fortunate to study in a very green campus, but getting them personally involved in tree planting instills social responsibility in them. We want our students to walk the talk, when it comes to being conscious towards the environment. It is part of the IIM-K budgeted for green campus initiative, which started in2011 with the constitution of the Campus Afforestation Committee. Faculty, staff and students together identified 33 areas where they estimated 800 trees can be planted and nurtured. The barest areathe residential hill of the campuswas targeted first. A second committee, Campus Green Initiative Committee was constituted to implement these recommendations. To augment the availability of water for trees, rain water has been stored in water storage tanks and in renovated cement tanks located across the campus.
EXPANDING THE SOLUTION:
The acquisition of 15 acres to house IIM-Ks new campus development programme spurred the management to replicate the success story. The second phase of the rainwater harvesting project is similar in design to the earlier phaseit involves another five acre catchment area and storage pond dug out at the foothills. Our water needs are growing. Doubling the storage capacity, collecting an additional 50000 cubic metres of water, will ensure total self-sufficiency in water even during years when rainfall is deficient. It will further improve the water table level, shares Professor Chatterjee.
Accomplishing self sufficiency
Phase I of the project captures the runoff from about 66% of its original 96 acre campus.
Phase II will capture 60% of the runoff from the 15 acre addition to the campus on the east side.
The tree planting initiative launched on World Environment Day 2012 saw over 300 trees planted in eight locations. The second phase launched on World Environment Day 2013 targets planting about 250 trees.
RAISING THE BAR:
In making significant gains from its vast campus and being located in a place which receives over 300 centimetres of rain, IIM-K has set new standards for water self-sufficiency and for green campuses. It meets its daily need for over 300000 litres of water from harvested rainwater alone.