Atmospheric analysis

How do horticultural activities potentially influence water flows?

What are the potential sources of chemical contamination from horticulture activities?

What are the potential sources of nutrients from horticultural activities?

How may horticultural activities increase sediments in waterways?

How do instream barriers as a result of forestry activities potentially influence water resources?

How may forestry activities impact riparian vegetation around a waterway?

What are the potential sources of chemical contamination from forestry activities?

What are the potential sources of nutrients from agricultural activities?

Discharging into a waterway is likely to impact water quality.

NIWA has produced revised safe levels of dissolved oxygen for fish, which will help inform future environmental planning and resource consents and help to keep New Zealand rivers full of healthy fish.

Setting water quality standards is a tricky business. Suitability for use is currently judged against guidelines that suggest water suddenly becomes ‘unsafe’ when a particular variable changes beyond the guideline value. For instance, according to MfE microbiological water quality guidelines (published in 2003), water is considered unsuitable for swimming once levels of E. coli – a microbe that indicates the presence of faecal bacteria – exceed 550 E. coli per 100 millilitres. But is it suitable at 500 per 100 ml?