On our burgeoning African planet, there has always been a big shortage of housing for the teeming masses. But because governments are looking to address these shortages, the result has been the provision of total town and village developments, providing complete living environment for thousands of families on the continent. One vital service that needs to be implemented when constructing government housing projects is storm water control design.
Water needs to be filtered
Paving systems have been developed to deal with storm water in a controlled manner, and the permeable paving systems is the ideal choice, helping to relieve the already overloaded storm water infrastructure and outfall canals. The system is installed using an infiltration system so that the water is filtered and cleaned to a pH neutral standard before filtering downwards to the underground storm water control systems. This creates no major impact on the existing infrastructure and watercourses.
Grids to catch dirt
Predominantly laid in the parking areas of the housing developments, the paving system solutions will deal with surface run-off as well as roof and verge flow. Tests also showed that there was penetration of sand into the 3 mm grid between the pavers, up to as much as 1 cm, so where necessary, sand traps have been introduced at strategic locations around the housing developments to trap windblown sand into the grid and therefore to alleviate a notorious problem across the region.
Future water management
Plans have been set to inspect the paving at regular intervals, with both the government authorities and private sector working together to assess the success of the installation, ease of maintenance and above all, the system’s suitability for the control and treatment of storm water. A water table monitoring system has also been installed to monitor the storm water run-off system below the social housing development, which, over time, can be used to review the performance of the permeable paving above.
Managing the quality of storm water and grey water in informal settlements is essential to the government housing growth. The building and maintenance of streets and pavements as well as storm water drainage systems are usually the first services which must be provided in urban areas of government housing. In the small villages and other urban areas with small populations the people can usually still strategise the need for water, but when the population becomes large, a reticulation system to convey water to the people must be constructed and maintained.
In some of the government housing projects in South Africa that have experienced delays in control of storm water in the past, government is catching up with storm water programmes which will entail monitoring the quality of the water in rivers and tributaries nearby with appropriate remedial actions being taken where necessary. They will construct the balance of the underground piped systems in terms of the existing storm water master plan that has never been completed and will construct energy dissipaters at locations where storm water velocities are excessive to as to eliminate or at least minimise erosion. They are also having grids fitted to all storm water inlets to minimize the ingress of street litter into the storm water systems. All information regarding the as-built situation will be consolidated into one overall storm water master plan, and recorded on an accessible integrated functioning graphical information system.