Posts Tagged ‘Ground water’

Severe water shortage looms in Jaffna

September 27, 2013
Climate change, over-extraction of groundwater due to resettlement and with no rivers flowing through the peninsula, its aquifers are fast depleting 

The first elections in Jaffna since the war ended was held yesterday with many political promises. However, experts point out a water shortage silently looming in Jaffna, that will affect the people beyond these political promises.  The fact that Jaffna will face a severe water shortage in the future, if water extraction is not managed, has been revealed by a study done by Jaffna University’s Department of Agricultural Engineering. No river flows across the Jaffna peninsula.

Hence, the groundwater in the limestone aquifer is the main source of water for the area. Aquifers are underground layers of rock that are saturated with water that can be brought to the surface through natural springs or by pumping. The extracted water must be replaced by new water to replenish or recharge the aquifer. But in Jaffna, this recharge rate is 0.57 million cubic metres (MCM) of water, while the extraction rate is 0.66 MCM, according to research done by M. Thushyanthy and C.S. De Silva. So, Jaffna’s limestone aquifer will become depleted over the years, these water experts fear.

Rapid development of agriculture, economy and increase of population due to resettlement, creates greater withdrawal of water. Especially, water extraction for agricultural purposes will impact Jaffna’s water resources, according to this study.
However, this situation is not only restricted to Jaffna. Sri Lanka’s aquifers located in other areas will also face similar issues, says Water Resources Board (WRB) Director General R.S. Wijesekare.

He fears the changing rainfall patterns due to Climate Change will impact Sri Lanka’s groundwater aquifers. Not only the drought, but intense rain during a short period of time, will also disturb groundwater recharging cycles, as it will not allow rain water to leach down, but runoff quickly into rivers. The presence of buildings prevents rainwater from leaching, hence leaching in urban areas is severely reduced, which slows down groundwater recharge, while groundwater extraction for commercial purposes is increasing. Hence, a solution needs to be found for the future, point out water experts.

At least for the Jaffna aquifer, the Jaffna University researchers recommend the establishment of an institution for a groundwater regulatory framework, to optimise its usage by controlling its overuse.

Published on SundayTimes on 22.09.2013 http://www.sundaytimes.lk/130922/news/severe-water-shortage-looms-in-jaffna-63294.html

Excessive use of agrochemicals pollutes groundwater in many places

September 27, 2013

Last month, the Sunday Times highlighted that Sri Lanka’s farmers were over-using agro-chemicals, and warned that it could ultimately penetrate into the groundwater. This has now been confirmed by a study conducted by the Water Resources Board (WRB).

WRB Director General R.S. Wijesekare revealed that chemical compounds such as Nitrates, Phosphates and heavy metals were found in excess in many places in the districts they surveyed. The survey covered Jaffna, Ampara, Puttalam, Anuradhapura, Matale and Gampaha districts. Excessive Nitrate compounds were in samples taken from Kalpitiya and Jaffna, while Phosphate was in abundance in samples taken in Ampara. In samples from Anuradhapura, heavy metals such as Arsenic were found in quantities exceeding standard levels, he confirmed.

Some of the agrochemicals will be absorbed by plants, but most of it will collect on the soil or be washed away as runoff. Part of it leaches through to the groundwater. What goes in will come out, so not only the people in the immediate vicinity, but others in the area too could be affected by contamination.

Water samples from 30 Secretariat Divisions covering these districts have been collected periodically, under this study initiated in 2011. Mr Wijesekare said that the results have highlighted the need for some control of using agro chemicals. He said that WRB with other agencies such as the Agriculture department and farmers are planning to conduct a program in Puttalam to educate farmers to use the Agrochemicals responsibly while monitoring the ground water periodically to check for improvements of the quality. He also said the survey has been done on a Pilot scale and are trying to do the exercise covering the whole island.

Head of Sri Lanka programme of International Water Management Institute (IWMI), Dr Herath Manthreetilake has also stressed the importance of having such programmes at least in priority areas prone to groundwater pollution.

He also pointed out that periodic monitoring has to be continuous, to get a clear idea of pollution levels. Isolated incidents of chemical spills on depleted groundwater reserves due to drought, can increase the concentration of chemicals, so the results may not be entirely accurate – but data captured periodically on the groundwater condition can give a better picture. Dr Manthreetilake said that groundwater in most industrial countries such as Japan, are polluted beyond usage. Therefore, to avoid falling into the same trap, it is important to continue with a proper monitoring mechanism of groundwater sources.

Published on SundayTimes on 22.09.2013 http://www.sundaytimes.lk/130922/news/excessive-use-of-agrochemicals-pollutes-groundwater-in-many-places-63297.html