The design is meant to provide an effective barrier and feeding trough. The length of the trough is important as pregnant ewes need lots of space to feed, 50cm (20 inches in N. America and Wales). Only one more job to complete, we need a water supply. Tapping into the water main is horrendously expensive so the plan is to capture rainwater from the roof.Here is where I have to revert to Imperial measurement, Seventy square metres (77 sq yds) of roof should harvest how much water?
If an inch of rain falls on an acre of ground that inch is equal to 22,610 gallons (27,154 US galls). this is where I have to open a spreadsheet! The roof area is 0.0159 acres so it receives 360 imperial gallons for every inch of rainfall (1617 litres for every 25mm rainfall).
So no shortage of supply its just a matter of finding a couple of containers that are big enough.