Rain Gardens and Patterson Park

How Wetlands Work

I have made no progress in my basement water harvesting project; I am waiting for quotes before I make a final decision on the specific elements that I want on my site. One new idea is to sink a tank into the ground where I wanted the wetland pond to be.

It is as though everything has come to a standstill at this turn of the season and that more important than a quote is that I make a decision that supports the environment on my property. And that I don’t lose track of the intentions of my original vision for it.

I have used this time to meet with people and to research alternatives. Instead of a wetland canal system ending in a pond at the bottom of my property Andrea Rosen, from JUFA, introduced me to the concept of rain gardens.

This is actually what I wanted from the beginning and was using the wrong terminology. An artificial wetland pond mimics a wetland in its use of plants but retains the water in the pond which is non-permeable. It is more of a garden feature than the useful eco-friendly intervention that contains both elements.

 

In terms of understanding the Patterson Park wetland system I also met with a local architect and environmental activist. She said that one of the challenges we face is scientific classification which impacts on planning and development in the city.

A cross-section of the Midrand Granite Dome

Midrand Granite Dome Cross-section

As I understand it Orange Grove sits on the Midrand Granite Dome which in theory makes it impossible for a wetland to exist in this area.

In addition, our wetlands are often seasonal and do not conform with other criteria used by northern hemisphere scientists in their descriptions of wetlands.

Both these facts lead some influential local scientists to resist classifying Orange Grove as a wetland area. In reality the wetland exists on top of the dome.

I was reassured that the infrastructure put in at Patterson Park is well designed and executed. It is a hybrid system that integrates natural wetland elements with engineering, allowing water to sink into the ground at specific points, while directing excess flow through designed elements.

Patterson Park silting up

Patterson Park silting up

It does need ongoing attention and maintenance; she too is concerned with the silting up at the main pond.

My concern that our stormwater system is old and in need of renewal is thus not misplaced for in addition I have also heard that the system is being compromised by sewerage which has made its way into parts of it. This in turn ends up at Patterson Park raising concerns regarding health.

In the midst of this stormwater infrastructure collapse in Orange Grove is the city’s goal to densify. We have a serious housing backlog so the more units that can be added per square kilometre the happier our politicians are.  As, in theory, the happier will be the people whose living conditions have not improved since the end of apartheid.

In principle I am for inclusive policies and actions. Yet there appears to be a mismatch between the nodal review, which some people are calling social engineering, and the city’s ability to deliver what people actually want. It has therefore taken me a while to articulate what it is that I want; I want a city that is environmentally sustainable, or as John Clarke, a social worker and activist expresses it, a city that includes environmental well-being in all urban designs.

In relation to Orange Grove this means acknowledging the reality of the wetland we live on. In practical terms I have been told that this means that three story buildings are the upper limit for apartment buildings.

Yet beyond this, what is essential is the delivery and maintenance of the stormwater infrastructure to support all planned densities. To ignore this is to disregard what many of our citizens want – healthy living spaces that make buying a home, no matter how small, a good investment.