Zandvlei Trust

SAND RIVER CATCHMENT FORUM

Minutes of meeting held on Tuesday, 08 May 2012 at 13:30 in Room A, Plumstead Office (Plessey Building)

Present
M Thompson                      CoCT: CSRM      (Chairman)
Linda Scholtz                     CoCT: R & S       (Minutes Secretary)
Peter Wium                        Peter Wium Cons Eng
Gavin Lawson                     ZVT
Ann Coltham                      CHRA
Nicola Okes                       UCT Zoology
Mandy Noffke                     WESSA
Candice Haskins                CoCT: CSRM
Melissa Tang                      CoCT: WPC
John Green                         WESSA: ZAPO
James Forsyth                    FOTP
Jean Fillis                           F of Kirstenhof Wetlands
Erica Hobbs                        F of Kirstenhof Wetlands
Denis Davey                        F of Die Oog
Cassy Sheasby                  CoCT Biodiversity
Chandre Rhoda                  CoCT: Invasive Species
Louise Stafford                   CoCT: Invasive Species
Liz Brunette                       Councillor: Ward 62
Brian Ratcliffe                     Constantia Valley Greenbelt

Apologies
Pauline Pearce
John Fowkes
James Rawlings.

As per the attendence register.

1. Welcome / Apologies & Attendance Register.
The Chairman welcomed all to the meeting (see list above) and handed out copies of the Agenda and Previous Minutes.

2. Approval of the previous Minutes.
No Amendments were reported.

3. Action items from the last Minutes.
Report back on:
(i) Westlake Management - looking at improving the quality before it reaches Zandvlei. Cassy confirmed that she did not think that it was worth the effort to get a burning permit. MT suggested that they wait for the authorisation process that is presently underway to be completed. Once obtained they will meet with Julia Wood and undertake works on the southern bank of the Westlake River during late summer of 2013, which will allow some polluted flows into the southern wetlands.

4. Additional items under General.
none added.

5. Permeable Paving - Peter Wium.
Peter Wium gave an interesting presentation on the use and benefits of permeable paving.

Sustainable Urban Drainage System:

  • This has been widely used in the UK and is in line with the policy of the City.

  • Some of the benefits are that it limits the infiltration of pollutants into the groundwater, reduces the risk of flooding from run-off as it holds back water flow.

  • Various Case Studies were presented ie Military Road, Steenberg Social Housing Development, an Industrial area and the parking at Blue Route.

  • These pavers are also being used by Developers.

  • This is also a means of controlling water in residential areas where water can be re-used.

Design:

  • Constructed to specifications

  • Underlayed with a Inbitex geotextile

  • Subgrade (various) depending on use

  • 200x100x80mm Aquaflow pavers

  • Gaps filled with grit to lock the system

  • The maintenance is minimal. Brushing to be done once a month to keep stones open.

  • Every 15 years filter and stones to be replaced.

6. Constantia Property, Cnr Firgrove and Spaanschemat Roads – Ann Coltham.
Ann is the chairperson of the Constantia Land Steering committee gave her report. The area of concern is cnr Firgrove and Spaanschemat Roads, opposite the Uitsig Wine Estate, which is earmarked for land restitution. This committee has been working closely with the claimants for the past 3 years.

A consultant team was appointed some time ago and feasibility studies are underway and a report of the findings is due by the third quarter of this year.

Kobus Scott and Keith Roman are lead members of the consulting team.

7. Zandvlei the recent Algal Bloom episode - Candice Haskins.
Once again an in-depth presentation was given by Candice informing all on the algal bloom and fish kill episode in Zandvlei.

These are some points to highlight the situation in the area:

  • Samples were taken and E.coli levels were within the recreational guidelines

  • Salinity levels were good

  • High water temperature

  • On 27 March 2012 there was an elevated level of chlorophyll, and Green algae was identified in the samples

  • No blue green algae/toxins were present

  • Investigations with reference to the 1973 fish kill presented the Prymnesium parvum.

  • Tests on samples on 16 April confirmed that this “Golden algae” P.parvum was present.

  • Heavy Easter rainfall (7 and 8th) and other coincidences could have caused a spike in nutrients which fuelled the development of the algal bloom. It is thought that the bloom began in the Marina canals

  • On 25 April results showed a decline in the Golden Algae levels.

  • On 30 April the mouth to the estuary was opened, and may be kept open for the duration of the Winter months, depending on various factors such as water depth and salinity.

  • The clarity of the water has recently improved.

  • Many photos were taken by I Cramna and C Haskins.

Thanks were extended to Management who handled the situation well under the circumstances.

The Zandvlei Estuary Forum was formed in partnership with Cape Nature and the City. Three Technical Working Groups will be meeting to discuss various issues relating to management of the estuary (hydrodynamics & water quality; pond weed management; fish population dynamics).

8. Otter Research - Nicola Okes.
Nicola is doing research into the habitat and movements of the otter in the Cape Peninsula for her PhD. The sightings and findings and how these interesting aquatic mammals are adapting to the declining water quality in the urban environment will be investigated.

They look a lot like seals with a long tail and stubby legs and are consequently sometimes confused with seals. They could be found anywhere in South Africa where fresh water and reeds are found, and make their breeding dens (holts) in heavily vegetated areas.
They are top order predators in rivers and wetlands and form an important role in regulating and maintaining the ecosystem’s health. Their reliance on fresh water puts them at risk to pollutants and therefore this research was started.

Their sightings are difficult as they are usually seen at dusk or dawn. Camera trap surveys will be set up not only for otters but other animals as well. Unusual sightings were in Kloof Street, Manenberg and Athlone, pups were born in Zandvlei and Silvermine River Wetlands and Hout Bay. They move through the drainage system and golf courses.

Sadly, dead otters have been found in various areas around the Peninsula such as along Liesbeek Parkway and Kommetjie Road.

Nicola has requested that to assist in the research being done, any sightings are reported to her on any of the following contacts or uploaded on the site below:
cell  082 961 9082 
email nicolaokes@gmail.com and www.nicolaokes.co.za

9. Westlake River and Pollsmoor – Melissa Tang.
Samples have been taken up to Drift bridge. Results showed poor water quality from Westlake Housing and Pollsmoor Prison.

Westlake RDP housing
This is an ongoing problem where backyarders occupy property and overload the system. The problem will not be solved until adequate services are provided.

Pollsmoor Prison
After many attempts to meet with the prison officials to discuss issues affecting the pollution, Melissa eventually made headway.
They are renovating their kitchens which will include grease traps, and drainage to sewerage. On the positive side, they are willing to work with the City.

Compliments and thanks were extended to Louise and Chandre on what they are doing.

10. General.
James reported:In collaboration with Louise Stafford a quantity of alien invasives had been removed from the Pollsmoor Prison precinct. He had hired a chipper so that no material was removed from the site. This had all been arranged with Mr De Vos at the prison, who is in charge of health and safety.

James is hoping to arrange an exchange of undertakings whereby he will arrange further removal of invasive aliens in exchange for the prison authorities arranging a cleanup of the river system.

Cassy announced that she would no longer be attending the meetings as she has resigned. Her participation and input has been appreciated.

11. Next Meeting.

28th August  2012 – The venue will be Room A, Plumstead Offices (unless specified).

                                                                                                                                               

Top of page  Back  Home