Tamil Nadu - Coimbatore   

Poor rainfall, but no water scarcity

G. Satyamurty

Rainwater harvesting comes in handy The district has received only 261.64 mm rainfall so far. Rainwater harvesting and heavy rain in Kerala come in handy

COIMBATORE: Coimbatore district, which is chronically water-scarce, has received very poor rainfall so far. But its reservoirs are full or fast filling up. Its groundwater level is also healthy.

The normal annual rainfall of this district is just 714 mm. Even Dharmapuri district, which was identified as one of the worst drought-prone districts in the entire country as early as 1975 and granted the Drought-Prone Area programme, has an average annual rainfall of 879.1 mm and Krishnagiri district (which was recently carved out of Dharmapuri) has 830.1 mm.

Coimbatore district, which has been suffering successive droughts, received only 435 mm during 2002 and 570 mm during 2003 resulting in withering of lakhs of coconut trees, which is the backbone of its agrarian economy. Last year; it was slightly better with 669.5 mm. During the current year, the district has received only 261.64 mm so far.

But, curiously, most of its reservoirs are getting copious inflows. They include those coming under the Parambikulam- Aliyar system (that irrigates lakhs of acres) and also Siruvani and Pilloor, which supply drinking water to Coimbatore city and suburbs.

Dams surplussing

While Sholayar reservoir started surplussing on Thursday, Amaravathi is expected to surplus on Friday. Also Siruvani and Pilloor reservoirs have started surplussing, thus, ensuring immense relief to the water managers of the city.

Interestingly, almost all these reservoirs have catchments in Kerala, which is bordering this district, and the torrential showers in that State has proved to be the real saviour of these reservoirs.

According to Tamil Nadu Water and Drainage (TWAD) Board sources, rainwater harvesting structures - roof top harvesting and surface harvesting— in both urban and rural areas of this district, which were completed on Aug 31, 2003, have now come in handy.

These structures were installed in 9,379 Government buildings and 9.35 lakh private buildings, institutions and individual houses in the phase I scheme. In the phase II, additional 3.19 lakh structures were completed.

Study held

Then, a scientific study on the impact of rainwater harvesting was carried out to assess the groundwater level and quality.

Accordingly, 154 borewells and open wells were selected and monitored periodically.

A rise of 7.18 metres in water level was observed during October 2004, 4.9 metres during November and 0.7 metres during December. Thus, the total rise in water level was 12.78 metres in just three months.

Interestingly, according to TWAD sources, "an abnormal rise of 1.42 metres" in water level was observed during May this year.

This could be because of an unexpected bounty of 105.3 mm rainfall during April this year against the normal 55.9 mm and 115.3 mm during May as against the normal 77.9 mm.

"The total rise in groundwater level during the one year from May, 2004, is almost 14 metres," they said.

Sources point out that during June (the beginning of the South-West Monsoon season), this district received just 21.1 mm rainfall and during the current month also it has been extremely poor.

Hence, they assert that but for the rainwater harvesting structures, the groundwater level position in the district would not be so healthy.

Printer friendly page  
Send this article to Friends by E-Mail

Stories in this Section

Poor rainfall, but no water scarcity
Dyeing units: risks do not deter investors
Shantanand Saraswathi passes away
Around the City
In Coimbatore Today

Copyright © 2005, The Hindu. Republication or redissemination of the contents of this screen are expressly prohibited without the written consent of The Hindu