Ms Mary Gurrie:

Yes. It breaks them up into stretches for management purposes and the reason this is the case is to address exactly the problem the Senator described. As a rule, the best quality rivers are usually up in the highlands and the upper stretches. As the Senator said, rivers gather the various pressures on them as they flow down their courses. This is why the estuaries are generally in the worst condition. They are taking all the catchment water that comes into them. Each river water body is assessed. When we talk about 1,000 river water bodies, each one of these stretches is assessed. Sampling is done for the nutrients, such as nitrogen and phosphorous, between four and 12 times a year, depending on the stretch of river. The biology sampling is then done once every three years at least.