First of all is the Mangatawhiri River safe enough to swim or drink in? I think that the river is safe due to little chemical runoff and the river is fast flowing giving more oxygen in the water. We recently planted plants on the bank of the river, these plants will prevent erosion and temperature rises in the river. For example we did tests on the river gathering a small amount of organisms, we found that they had an average sensitivity rate of 6.21 that makes them highly sensitive to polluted rivers. It is safe to say that our river is safe and clean to swim in for fish and families.