Ghana’s Perennial Flooding from an Engineering Perspective Part 2

A Voice of Reason in the Midst of Chaos and Wailing – Ghana’s Perennial Flooding from an Engineering Perspective

Part 2

In part one of this article, I looked at the possible cause(s) of perennial flooding in Ghana based on anecdotal evidences and engineering judgement. In part two, I have proposed some short term and long term solutions as well as policy recommendations to government/relevant authorities.

Short term engineering solutions

Government/Relevant Authorities should:
Provide the Meteorological Service Department with data gathering and Flood Forecasting equipments.

Carry out forensic audit into Ghana’s drainage infrastructures to ascertain the cause(s) of the perennial flooding in the country.

Conduct a comprehensive topographical Survey of all surface water courses and their surroundings.

Design and construct flood embankments along streams and rivers at risk of overflowing their banks in the event of heavy rainfall (materials for construction are readily available in Ghana).

Design and construct detention ponds/basins along at risk streams and rivers.

Dedicate lands (buffer zones) for deliberate flooding, which could also be used as parks /recreational grounds in dry weather conditions but allowed to flood in the event of heavy down pours, to protect nearby settlements.

Improve drainage channels with detention basins near the sites.

Undertake Cleaning of clogged cross drainage works like culverts, Water ways etc.

Properly evaluate the capacities and hydraulic conditions of primary and secondary drainage channels on the basis of topographical surveys.

Provide additional waterways by remodelling/constructing culverts and bridges.

Survey approaches and outfalls of drainage channels and correct defects where necessary.

Improve channel conditions by way of removing local obstructions by weed growth and garbage, removing unnecessary bends along water courses, interlinking of channels, digging new drains and providing waterways under roads.

Develop an annual inspection and appraisal scheme for all water courses and drainage infrastructures.

Long Term Engineering Solutions

Government/Relevant Authorities should;
Construct reservoirs and underground water storage units

Policies

Government should register all consultants and contractors deemed fit to work on government projects based on their competencies and capacities.

Establish an Engineering council by an act of Parliament made up of practicing engineers to oversee the design and construction activities of contractors and consultants. This body should have the powers to monitor and carryout forensic audits into works completed by contractors/consultants and should have the mandate to strike off consultants from being involved in government projects if they are found to be cutting corners and compromising the quality of the project.

Awarding Design and Build contracts should not solely be based on cost but quality.

Provide bins for disposal of litter at vantage locations across the city to stop people from throwing litter about indiscriminately.

Introduce a retention policy of about 10% of the total cost of construction contracts, where this amount will only be paid to the contractor when the Engineering council is satisfied that the work has been completed to a very good standard and has been carried out as specified in the design.

Government should as a matter of urgency, use data gathered from topographical survey of water courses and their surrounding areas to establish buffer zones along at risk water courses, where nobody is allowed to build.

Parts of these buffer zones should be used for recreational grounds/public parks during the dry season but allowed to flood during heavy rainfall (Deliberate flooding) should the flood waters overtop the embankment. Government can do this by passing a law, where she is able to compulsorily purchase lands within proposed buffer zones which have not yet been developed from their owners. This must apply only to lands along water courses. These lands must not be used for any other reasons apart from recreational/public parks.

In areas where people have already put up buildings in waterways and flood plains (i.e. within proposed buffer zones), government should set up a body made up of experienced social workers and negotiators to immediately begin some consultation processes with the affected property owners, with the aim of either resettling them or compensating them before pulling down their houses to create these deliberate flooding areas (Buffer Zones). The mere pulling down of houses in waterways and flood plains without any engineering input after the demolishing exercise to turn those areas into flood detention basins, will be a waste of time and resources.

This buffer zone policy should be passed into law so that anyone who encroaches on these lands could be prosecuted at the law courts. It’s about time we re-think our land ownership laws. Land may belong to say a chief, but it is for the government to decide what sort of development is permitted on a piece of land; in this case people will have to put in planning applications for approval. Land owners and developers who flout these laws must be made to face the full rigours of the law.

I may sound a bit apocalyptic here but if we do not adopt a comprehensive approach to mitigate or control the problem, it is only going to get worse and the dark spectre of perennial flooding and poverty will continue to stalk us as a nation.


David Klutse
Geotechnical Engineer
d_klutse@yahoo.co.uk