Typical daily
water needs figures for a sedentary individual are: • Urine — 1.2 litres • Feaces — 0.75 litres • Skin
evaporation — 0.4 litres • Respiration — 0.15 litres •
Total — 2.5 litres An hour
of exercise uses another 1 - 2 litres
of water, depending on training...
Only about 40 %
of the
water reaches the crops, while
evaporation in the hot sun takes more than two metres
of water a year from the reservoirs - a
total of around 300m cubic metres from Elephant Butte alone.