STORMWATER MONITORING

CASHMERE STREAM SEDIMENT SOURCES
Service Areas: Stormwater Monitoring, Urban Ecology

Community concerns regarding sediment in Cashmere Stream led Environment Canterbury (ECan) to commission EOS Ecology to undertake a detailed study of the stream’s sediment inputs.

The scientists at EOS designed an extensive sampling programme to pinpoint the source and types of sediment entering the stream. Encompassing the monitoring of 81 sites during one dry and three rain events, this project identified the top five contributors of sediment to Cashmere Stream. This information is key to dealing with sediment inputs on a catchment-wide basis which will ultimately also benefit the downstream Heathcote River and Avon-Heathcote Estuary/Ihutai.

TRANZLINK PONDS TREATMENT EFFICIENCY
Service Areas: Stormwater Monitoring, Applied Research

Interested in measuring the performance of their stormwater treatment systems, the Christchurch City Council has commissioned EOS Ecology to assess the treatment efficiency of the Tranzlink ponds which treat stormwater in a predominantly industrial catchment.

The EOS team undertook a baseline dry weather study of the treatment system and then developed a stormwater sampling programme to monitor contamination loadings in the influent and effluent flows. EOS’s programme is designed to capture information on the first flush, as well as prolonged storm events; with samples collected via multiple automatic samplers being analysed to measure the levels of pollutants such as heavy metals, chlorides, nutrients, and suspended solids.