Discussion on Rainwater Harvesting

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There is a wealth of information on rainwater harvesting that could be shared here. If you have any resources, ideas, links or questions relating to rainwater harvesting, please place them here.

Lets get a good discussion going!

Dear Mr Walude!

How a u and ho is it going? well i have seen you on several villages mainly on the task of water harvesting, yes! i can see that ground tank is good but what procedure do u put in that tank to prevent water contamination, you know when water is in the tank like that, germs come in? even it can act as abreeding place for mosquitoes.

Iam here drafting aletter which is to go to an org in Canada but before i can send it, i would like to know how much money does it require to make that tank so that i can put the amount in the letter.

reply me if possible.

kind regards


Dear Frank!

Thanks for your enquiry into rainwater harvesting.

Ground water tanks are good where communities have no other option e.g. those using extremely salty water, or water with a lot of iron or water with a lot of lead or fluorides. It is also relevant for communities in water scarce areas where even borehole construction is not feasible.

Communities in such areas resort to water from ponds or any sort of open fresh water bodies that are actually fed by rain. Such fresh water bodies will in most cases be heavily loaded with bacteria due to contaminated surface inflow.

Substituting these kinds of water sources with ground rainwwater tanks fed from controlled catchments reduces the bacteriological load and leads to cleaner (with a clear colour) and safer water for bathing, washing and cooking. An undrground rainwater tanks can store large amounts of water for use by the entire village especially in the dry season.

Ofcourse drinking water must be boiled before drinking as it will be prone to construction. Every household must be educated on safe water handling (including boiling drinking water).

Contamination cannot be fully preveted but can be minimised by constructing diversion chambers with control valves so that the first flow after a dry spell is always diverted. The tanks have to be inspected and cleaned at the end of each dry period when they are about empty. After cleaning, disinfection with chlorine is mandatory. Storm water must never be allowed to flow towards the tank and sufficient drains must be made to divert it from a distance.

I have attached the much promised budget for the underground water and water jar. The actual costs shuold be determined within your local area. When introducing underground water tanks in the area, also consider providing water jars for every beneficiary household. This will enable each household to use water jars in the wet season as they wait to use water from the underground tank in the dry season.

The catchment area for the underground tank can be a rock, a large building with corrugated roof or an artificial rock surface. if you consider using an artificial rock surface, then include a cost of 20% of the total cost for building the undrground tank.

I hope this will help.

Kind Regards



Dear Mr Walude,

Iam sorry to take long with out replying ,u know iam farmer trying to enlarge my garden, it needs lots of time, well iam glad to see your reply.

Now the budget is so expensive!! i dont know the money which is inside, i have never looked/touched at that cash, u know u guy, lets look for cheaper means and your tank only minimizes bacteria but i have got another formular which is this:

Have u ever heard of abio sand filter, here aperson doesnt require to boil water, he just waits for some few minutes then he drinks, it totally eliminates bacteria 100% it was tested in the US and was proved by scientist, i dont have its picture here but i hope Barb briggs has it but i dont know if she can help me to bring it here for u to see. Its cheaper to make and every home can posses it. Iam planing to bring that thing in busukuma but with time .

i luck your reply plzzzzzzzzzzzzzz.

kindest regards


Thanx Vijai for that update, hope everybody will see how good it is. and i welcome any comment on it.

kind regards


Dear mr walude, i have got afeed back from that org i contacted, i can see u a an engineer how much will u construct for us 1000 biosand fiilters. let me know



Dear Frank,

I dont have straight forward an answer for you but I suggest that we work together to build the first Bio-sand filter using guidelines provided by Barb and local materials from your Busukuma area. After this we will be able to project the total cost for 1,000 filters.

Try and find time to visit me in Bweyogerere so we can work out arrangements. My contact telephone is 0782 48 17 48




Dear Mr Walude,

Nice to hear from u, iam glad to see that u have acepted that bio sand filters are ok,well i can see u want to use our soil to build the biosand filter, but i dont know if it can be made in our local soil can be worthy? hope it requires some cement etc

Will try to find some time to visit u so that we make some arrangements u guy!! but u know the past dazs i have been travelling to entebe trying to get some Nets that where donated by briggs {my ally} so iam trying to cover up dates occured during the process.

How ever i luck some ideas from u in the busukuma village regarding agriculture as u will see in on the site.

yo talk ya soon!!



Here is a great resource to help calculate how much rain you could save wherever in the world you live. All you need to do is zoom into your rooftop on the map, then draw a box on your rooftop, then click finished.

Rainwater harvesting Calculator

If you feel this is a useful resource, please give it a vote and leave a comment. Greatly appreciated!



Hello Fred,

Wonderfull app! I've just tried it for my home, and apparently I could harvest 15.000 litres a year.
It would be nice if it also displayed the size of the marked surface, so that communities can also use it to estimate the surface needed (when they're still planning and there's no actual roof yet)