Catchment Management at City of Cape Town

Dear Mr Parker

It is noted that several million rands are currently being spent dredging parts of the Zandvlei.

The reasons given for this are ostensibly

1)  to assist fish migration and

2)  to improve water exchange between the estuary and the sea.

Could council please explain the following:

1)    since the rubble weir and associated sand bar remains the principal bottleneck, how will this dredging improve estuary flow and fish migration long term? Alternatively, are there plans to remove or modify the weir?

2)      since the mouth is artificially blocked  for most of the summer months by the bulldozing of sand across the mouth, how will this dredging solve the problem, given that it is the bulldozed sand that is causing the siltation?  Or is it the council’s intention to discontinue the artificial closing/opening of the mouth?

3)      how will the success of the undertaking being measured?

i)                    Are flow meters installed in order to measure the amount of sea water being exchanged during the various tidal periods?

ii)                   Will sand deposition be measured and monitored?

An explanation of exactly what is hoped to be achieved by the dredging (a copy of the dredging proposal if possible) and how success is to be measured and monitored would be greatly appreciated.

Yours sincerely

Charles Whaley

For SAVE THE ZANDVLEI PETITIONERS

savethezandvlei@yahoo.com