Hello Dear..

You may construct water tank of 5mx3mx1m size required for 15000 liters water.

Thanks

if you are going to make a concrete water tank of 15000 litres then you can have simply two types of shapes of water tank ie a cube and a cuboid.

if you can send us your choise regarding the shape then we can send you the alternatives for your water tank design.

or in case if you are going with cube shaped then its very simple to find out one dimension of cube by having cube root of 15000cu.unit

or in case you are going with a cuboidal shape tank, then please fix up the height of tank according to your suitablity. we will send you the the lenght and width accordingly.