No.18 2006

Science Centres: Freshwater

When a river dries

CLUES to the big questions

Courses from the National Centre

Water resources outlook

Water resources review

CLUES to the big questions "If we allow large-scale conversion of forestry to dairying here, what would be the effect on water quality and on local living standards?" That’s the sort of big question faced by regional resource planners. To answer such questions requires tools for predicting the cumulative effects of multiple nutrient and sediment inputs at a larger catchment scale, while also incorporating an economic and social dimension.
Courses from the National Centre [Photo: Steve Le Gal, NIWA] The National Centre for Water Resources offers training in many aspects of hydrology and water management.
Water resources outlook (August - October) The following soil moisture levels & river flows are likely: North & southeast North Island: normal or above normal Southwest North Island: normal Northern South Island: normal or below normal soil moisture levels; below normal river flows Southwest South Island: normal or below normal Eastern South Island: normal
Water resources review (May - July) River flows Normal to above normal river flows occurred in almost all of the North Island. Flows were extremely high in the southeast of the North Island as a result of several floods, including the Ruamahanga River floods in early July. The east of the South Island also experienced above normal flows, including snowmelt runoff from the Canterbury snowstorm in June.
When a river dries Isolated pool on upper Selwyn River, January 2005. [Photo: Andy Davey, NIWA] Results of an extensive study on the Selwyn River in Canterbury will help water managers setting acceptable limits on water abstraction. The 18-month study by NIWA scientists involved comprehensive electric fishing surveys at 10 sites on the river to quantify the effect of stream drying on native fish communities.