Cape Town - The province’s Department of Infrastructure has had to close certain lanes of the N1 inbound near Sable Road for safety reasons.
This comes as a result of large pools of water on the roadway after two weeks of heavy rain.
The province has also closed lanes along the Sable Road Service Corridor at the second Century City access adjacent to the N1 outbound due to the weather’s impact.
“It is unsafe to travel on a very wet and flooded road surface, especially at speed, because vehicle tyres tend to lose contact with the road, causing vehicles to aquaplane and drivers to lose control. This is an unacceptable safety risk, and public safety must come first,” the province said.
Engineering teams from the Western Cape government are on site to find alternative ways to supplement the stormwater drainage process.
In addition to normal maintenance work, teams will clear the earth drains along with specialised high-pressure cleaning of the pipe culverts.
“Our engineering teams have liaised with the City of Cape Town and other organs of state, to attempt to tap into other existing systems to allow for the N1 stormwater drainage system to recover before the next major storm event.
“Unfortunately, the Western Cape government cannot predict how quickly the excess water will take to drain away so that all three lanes of the roadway can be reopened,” the province said.
The area is steadily drying out, and the roadway will be reopened when it is safe to do so.
The province said it is aware that these lane closures are causing heavy congestion.
The required lane closures are close to the point where traffic joins from the N7 southbound into town and multiple other routes joining the N1 inbound.
This is causing significant tailbacks on the N1 inbound and secondary roads.
Road users are asked to use alternative routes, if possible, when heading towards the Cape Town city centre or Century City, and factor in a significant amount of additional travel time, and to avoid any non-essential travel along this route for the time being.
“Regular road users will be aware that there is a wetland adjacent to the roadway on this part of the N1 opposite Century City and before the Century City Train Station,” the province said.
“The ground in the wetland has become so waterlogged and saturated that water is absorbing into the ground very slowly and is adding additional pressure to the N1 stormwater drainage infrastructure,” the province said.
They added that the wetland’s earth berm, adjacent to the N1, has been breached, resulting in excess water flowing from the wetland into the N1 road reserve.
“As a result of the wetland’s inability to hold and absorb the water the roadway has flooded. This is due to the compounded impact of several days of rain over the current wet season.
“Over time, the soil will become less waterlogged, water will be absorbed into the ground, the flooding will abate, and it will be possible to reopen all three lanes of the N1 in this location.
“The stormwater drainage system is designed to ensure that water moves from one side of the N1 to the other via a number of pipe culverts or along open drainage systems to where it ultimately discharges near the Koeberg Interchange, some 2km away from the current flooded area,” the province said.
The stormwater drainage system on this part of the N1 was designed to only deal with road-related water run-off.
Any stormwater drainage system is designed to deal with a particular set of circumstances, but two weeks of heavy rain has pushed the system well beyond its capacity and it therefore cannot deal with the additional pressure and water from the wetland area.
Cape Argus