Rainwater Harvesting Garden,University of Pretoria

Good afternoon Guys

I am posting this thread in response to a request by francoisve, just a quick introduction, my name is Jason Sampson and I am a member of the Department of Plant Science at Tukkies, the project is a new addition to the Botanical Garden which I Curate. It is essentially a million litre plus artificial wetland system that harvests rainwater from roofs and paving around it, it has different components and ecosystems, all which add to its function, which is a living laboratory, plant collection and source of irrigation water for the rest of the Botanical Garden.

The images are two front covers and an insert from some of the articles we have had in recently published, local landscaping and sustainability magazines. Anyone who wants to read the articles can go to https://www.dropbox.com/sh/rzwvt2elon76wj6/5e7OW22P0c

 

@Inyanga: I always wanted to harvest water for my tank. Do you know what the quality of our rain water is?

 

Is this on UP campus?

 

Our rainwater is high quality. The bird crap you get off you roof can cause some issues but otherwise its some of the best in the world! Of course, in my system the said bird poo is fish food...

 

@ozone. Yes it is, It surrounds the new Engineering 1 Study centre

 

Run-off from your roof etc. is a Big no-no. Mainly because you've got bird shit, dust, leaves and whatever decomposing in your gutter before it rains. Run-off water for a big dam or eco-system like the above article,maybe.....

 

@andries, the worst problems are caused by the "first flush" of the season, when all of winters rubbish is flushed suddenly out of the gutters. Rest of the season its more or less fine, and can even be drinking water if suitably treated.

 

I have a water catchment system they use in arid conditions basically a massive plastic funnel connected via a pipe to a container. It looks like this:



Was thinking of using it next time, but uncertain about the quality of the rain water.

 

I have no doubt that collecting rain water off of roofs is TOTALLY the way to go - fantastic idea especially in a water scarce country like ours.
However, I would like to suggest, it would only be suitable to use this water in large bodies of water e.g. ponds dams etc and not in a fish tank. I have a feeling that using rain water to store in smaller tanks or drums might be a problem. The organic matter that is collected by rain water and chanelled from a roof or paving, might start to decompose in a drum causing further problems, even more so if you heat that water for using in water changes. Paving or garden run-off water might also contain fertilizers or pesticides, so you would have to ensure that the collecting surfaces are void of any of those. One would have to filter and 'clean up' the rain water before storage. Then there is also the problem that some bird poop contains e-coli bacteria,and we really don't want that contaminating our water for fish tanks.The e-coli bacteria can then only be killed by ultra-violet lights.
Our rainfall is too erratic and when you have done your wc using the stored water, the next down pour might only be 2 weeks later - in summer - winter is another story with no rain for 5 months !. So then it's back to municipal water again. unless of course you have enough storage drums to collect like 5 or 10 or 20 thousand litres.
One also hears about 'acid rain' water contamination - sounds scary for my fish.
But then again, in the old days, lots of homes had a huge tank at each corner of the house, and that was the drinking water supply for the house.
So, the long and the short of it is this - Do any members here actually use rain water for their tanks on a regular basis

 

Im studying engineering at Tukd now and I find it so fascinating to study and watch the wetland through the window or even walk around it looking at all the life in the system.

 

What a nice read - thanks for posting and may I say - Job well done!!! Want to know more about the membrane used but will go and research it.

Later Ferdue

 

Just some of the plants around there... Took these yesterday for Jason aka @Inyanga...
1. Aloe

2. Acacia

3. Elephant ear 1

4. Elephant ear 2

5. Elephant ear 3


More coming...

 

6. Elephant ear 4

7. Elephant ear 5

8. Elephant ear flower

9. Flower spike

10. lily pads 1


still more coming

 

11. lily Pads 2

12. lily pads 3

13. Water lily

14. Marcilea schelpiana

15. Pink flowers


that is it... (For now...)

Now @Inyanga can come and ID everything for you guys... Because i cant...

 

Thanks man, we built this for the students, and particularly you guys (the Engineers), this project saved the Sudy Centre development about 6 mill in waterproofing and stormwater solutions. Green Engineering in action and at your finger-tips!

Regarding water contamination; since we use unleaded petrol nowadays the quality of what actually falls from the sky is pretty good, other than in places with large industry like Sasolburg or Witbank. Bird droppings are a well known source of E. coli contamination but you can kill such with Hydrogen peroxide, or run it through a wetland system built for water purification (gut bacteria are actually eaten by other organisms in such an ecosystem.)

The sail harvester will work just fine to collect water for a tank as it has no chance to build up gunk, set up before a rainstorm and you are away!

 

The liner is Firestone Pondguard. Its gort a fancy name but it is just rubber, chemically inert, imune to UV degredation and if it gets a hole, fix it with a bicycle tube repair kit...

Lovely photos Ludwig, Id's as follows: Aloe tongaense (dwarf tree aloe), Acacia anthophloea (fever tree, but the Kenyan form which may be a different species), various varieties of Matumi (Coclocasia esculenta), Phygellius (river bells), Nymphaeae capensis and N. lotus (this last an indigenous accession), Marallea schelpiana and Lobelia cardinalis hybrids.

 

Walked past there just a few minutes ago, and since the start of the project one could see the care that was put into this system.
And it is great. Few days ago I planted myself on my arse infront of Eng 2 waiting for a client, and just drank in the stunning views of this garden.
Escape on campus is great especially next to maths and the botany buildings, if a client pissed me off like the one I have to wait for is doing right now...

 

@fhmarais, it is a real pleasure and privalege to be able to create the things we do on Campus, and to hear from the poeple who appreciate them, and who's lives have been improved thereby. Thank you!

 

@Inyanga, I have always been fascinated wetland systems. I have never found out about cost. Would it be practical or even possible do do a reed-bed type system for a normal household, or can one only work with larger volumes of water. Can a small reed-bed convert grey water into clean water. I suppose it would depend entirely on the planting of the reed-bed and the volume of the flow of water. Is there a formula that one has to work to to have enough plant material to convert the grey water?

 

This is awesome, I'll have to find an excuse to get myself onto campus again to go check it out.
What's the livestock in the system at the moment?