Summary 2007-08



· Northland Regional Council (NRC) established the Lakes Water Quality Monitoring Network (LWQMN) in 2005.

· Water quality samples are taken from 31 lakes around Northland every three months to be analysed for a range of properties, such as nutrients and bacteria.

· Each lake is given a Trophic Level Index (TLI) according to the amount of nutrients present in the water, from hypertrophic (extremely high nutrients) to ultra microtrophic (very low nutrients).

· In addition, the National Institute of Water and Atmospheric Research (NIWA) surveys 82 lakes around the region every year to assess their ecological value. Each lake is given a ranking according to its ecological importance.

Performance Targets

Continue to implement and improve a prioritized State of the Environment (SOE) monitoring programme and monitor compliance with, and the effects of, the exercise of resource consents and Regional Plans by:

· Operating a region-wide water quality network for the measurement, recording and reporting of river, lake and groundwater quality trends - ACHIEVED

· Water Quality, weed and algae monitoring of Lake Omapere and associated community liaison and advice, including the ongoing development and co-ordination of a lake catchment management plan - ACHIEVED

· Reporting to the Council annually on environmental monitoring activities within three months of the end of the financial year - ONGOING

· Making the results from the annual SOE monitoring programmes available on the Council's website at - ONGOING

Summary of Results 2007-08

· Of the 32 lakes surveyed as part of the LWQMN, 53% can be classified as mesotrophic or oligotrophic and 47% can be classified as eutrophic or worse.

· Of the 82 lakes surveyed by NIWA, 51% were found to have moderate to low value, 28% were found to have moderate to high value and 21% were found to have outstanding ecological value.

· No new infestations of the pest plant ‘oxygen weed' were found in any of the lakes surveyed for this species however the pest plant ‘bladderwort' was found for the first time at Kai Iwi Lakes.

· An application has been submitted to release grass carp into Lake Swan (Pouto Peninsula) in order to control the pest plant ‘hornwort'.