By Joyce Danso
Accra, Nov. 08, GNA- Panelists, mainly scientists and researchers, have advocated the harvesting of rainwater by households to reduce over extraction of ground water and reduction of land subsidence.
The panelists noted that overreliance on ground water extraction has led to cracks in some houses in the city of Accra and the collapse of buildings under construction.
According to them, there were no policies on the volumes of water that could be extracted underground within a year and as the practice of drilling boreholes by households and institutions rises.
In a discussion at the ongoing first West African International Workshop on Coastal Land Subsidence at University of Ghana, Legon, the panelists stressed the need to educate the public on harvesting and storage of rainwater to reduce land subsidence.
The workshop sought to look critically at coastal land subsidence, its impacts on communities, infrastructure and eco systems in low-lying coastal areas.
It also sought to look at the primary causes of coastal land subsidence along the West African coast and how human activities have contributed to the phenomenon as well as look at the new technologies and methods used in monitoring and measuring subsidence rates in the region.
Land subsidence is a gradual settling or sudden sinking of the earth’s surface which usually results in cracks on buildings, flooding in low lying areas along the coast, sea erosion integrity of roads among others.
Prof Addo Kwasi Appeaning Addo, Project Investigator (PI) of the Engulf Project at the University of Ghana said generally subsidence in West Africa was quite low, but “we need to consciously make efforts to keep it low because we don’t want to get to a situation whereby it becomes high with the many consequences.”
Prof Addo said technical measures should be put in place, “we should have regular monitoring system because once we monitor regularly and there is any change in the rate, we be able to know it fast and therefore put in measures to regulate it.”
According to Prof Addo, Ghana has good policies but implementing those policies had become a challenge.
“How do we regulate ground water extraction. We should have a policy on the volume that can be taken and how many bore holes we should be allowed per year. I think these are things that we should be looking out for moving forward as a country.
If there are loopholes in the policies that are being implemented, we would identify those loopholes and ensure that the policy is working out.
We should look at alternative sources of water. Over dependence on ground water is going to increase subsidence rate.”
He called for the champion of harvesting rainwater adding, “we should start thinking outside the box because as we continue abstracting would increase subsidence.”
Prof. Amos Kabobah, Dean, International Relations, University of Energy and Natural Resources, Sunyani noted the houses put in Accra about 20 years ago have developed some cracks on them.
According to him those cracks follow a specific path but “these are some of the things we take for granted.”
Prof. Kabobah noted that in recent times, there had been reported cases of houses under construction collapsing because there were some things as country, we have not consciously decided to document them for further verification.
“We have good policies but it how we implement them. We have left out in our discussions one sensitive issue which is mining. Mining has further worsened our plight. In the Northern region most of our boreholes have dried up,” he recounted
He said there was no clear policy on recharge of ground water extraction, adding “our surface water is also polluted. We only have one option to harvest our water.
“One interesting issue in Ghana is that you will see in all our buildings we have gutters to collect our water, but there is no tank to collect to the water.
“We should advocate more for harvesting of rains to reduce extraction of underground water.”
Prof, Kabobah cautioned against closeness of boreholes and pit latrines in various homes saying the proximity of the two could affect water quality.
Stephen Djaba of Geo-Tech Systems Survey Limited and Inclusion Task Force Chair at International Federation of Surveyors called for data and knowledge sharing among institutions as a way of curbing land subsidence.
He said government institutions ought to be given financial assistance so that officials could go out on the field to collect data and offer information to the public and influence policies of government.
Global Navigation Satellite Systems (GNSS) Stations have been installed at the University of Ghana and Ghana’s Volta Delta under the Engulf Research Project to monitor and measure land subsidence.
The two-year Engulf Research Project focuses on addressing knowledge gaps in coastal land subsidence and relative sea-level rise along the Gulf of Guinea.
GNA