Redesign for Baakens project
● Flood risk reassessed to take impact of increased development upstream into account
A new Port Elizabeth building project on a prominent site in the lower Baakens Valley has been completely redesigned to take into account flood risk.
The development adjacent to the Shri Siva Subramanier Aulayam Hindu Temple in Upper Valley Road had to be moved further up the south bank of the Baakens River to cater for the threat of heavier flooding, Grant Hechter, CEO of project manager Synergy, said on Friday.
The site, comprising two adjoining erfs, originally housed a “Chinese shop”, a general dealer owned by Maureen Jackson, Eileen Lee Son and Herbert Low Ah Kee.
The property was bought in 2007 by National Pride Trading 351, which obtained permission to demolish the shop.
The property was sold on in 2011 to AME Properties which is building premises to house new tenant Radio Algoa.
Hechter said the new building had initially been designed to take into account the metro’s existing 1:100 year floodline but after a meeting with provincial environment manager Jeff Govender they realised this measurement needed to be reassessed.
“We appointed Hatch Goba and after seeing their study report we realised our development was intruding below the floodline and that we needed to completely redesign.”
The report noted that the last study on flood flow had been done in 1981 and that upstream increased development, “with Baywest to come”, had changed the dynamics of flood flow in the Baakens.
The study also took into account the new bridge on the corner of Upper Valley Road and Brickmakers Kloof, just downstream from the new project, because it could cause flow to back up.
Govender said on Friday that the main risk of increased flooding stemmed from the extra hard surfaces that came with the increased development upstream.
“Hard means impermeable. Rain cannot permeate into the soil and increased run-off is generated.
“So a new floodline has to be worked out. It’s not a static measurement. It has to be reassessed from time to time.”
A key recent development in the upper part of the valley, the Baywest shopping mall, was approved in 2015 by then MEC for economic development and environmental affairs Mcebisi Jonas after it had been turned down by his own department for reasons inclu- ding the floods it could trigger.
In October 2018, however, Baywest featured in a ruling by Bhisho that vetoed a proposed housing project in the catchment because of the combined effect of these developments on the integrity of the valley and the flow of the river.
Hechter said that in line with the meeting with Govender, Synergy had also appointed environmental consultant Dr Brian Colloty, who had recommended a range of measures to ensure they did not impact negatively on the valley.
In his Construction Environmental Management Plan, Colloty said that besides the importance of the 1:100 year floodline, the 32.5m environmental sensitivity setback from the river should be pegged to avoid possible encroachment.
At one point the contractor had to remove topsoil stockpiled inside this buffer zone, which had been noted by environment inspectors.
Colloty said that to prevent future erosion, slopes should be reduced during site preparation and “extreme care should be taken when importing top soils because they often contain seeds of vigorous weeds”.
“The objectives should be to re-establish a native vegetation cover similar in species composition to what existed before disturbance.”
‘So a new floodline has to be worked out. It’s not a static measurement. It has to be reassessed’ Jeff Govender
PROVINCIAL ENVIRONMENT MANAGER