Ferrocement tank

Ferrocement tanks are water tanks made out of iron and cement, usually some sort of rebar reinforced concrete cylinder sealed with a cement paste. The goal of this technology is to make a cost effective tank that is easily repairable and durable.

The WOT has a few different variations of the concept on their terrain, this specific tank was made in 1983 and gets filled by the Kijito windmill (link). It showcases that the two design goals: repairable and durable, were definitely achieved. It stores about 15,000 liters of water and can be used to test out various ram pumps like the Breurram (link).

This tank is featured in a YouTube video on different water storage methods (which also includes other tanks)