The Bay of Plenty Regional Council in New Zealand solves the problem of how to determine and maintain the trophic levels of its lakes using LakeWatch software…


“LakeWatch is a much needed software tool for analyzing water quality data quickly and easily. We can see the data graphically and how it changes over time. This makes it much easier to understand the waterbody dynamics and history. It also means that we can publish interpreted data in a form that the public and policy-makers can understand at a glance.

“We use LakeWatch to give us a quantitative assessment of the trophic (nutrient, clarity, chlorophyll) level of the water. It tells us whether things are getting better or worse and how quickly. In fact, we have now adopted the Burns’s Trophic Level Index for our lakes as a planning standard to determine land use options.

“What we like about LakeWatch is that it is all done at the click of a button where previously using spreadsheets and statistical packages took much longer. We were recently contacted by the head of the Lake Tarawera Residents Association who wanted to know about the lake’s nutrient level – using LakeWatch we were able answer the question while they were still on the phone.”

Environment Bay of Plenty, New Zealand

Environment Bay of Plenty (BOP) is a local government agency, established in 1989 to manage environmental resources (inland water, land, air and sea) for a large area of New Zealand. The area is endowed with a wealth of natural freshwater resources, important for both commercial (tourism) and recreational uses.

For a number of years several of the lakes had been reporting increased nutrient levels which in turn lead to problems, such as algal blooms and loss of water clarity. There were a number of different factors which might have been causing the problems and it was up to Environment BOP to pinpoint the causes and to stop the lakes from getting worse.

John Gibbons-Davies, at Environment BOP contracted limnologist Dr. Noel Burns to determine:

  • Trophic (nutrient) level – for each of the lakes based on historical data supplied
  • Trends – how quickly the lakes were deteriorating
  • Cause – why the lakes were getting worse

Dr Burns used the LakeWatch software to analyse the data from all 12 lakes. He was able to do this 5 – 8 times faster than the old method using spreadsheets and statistical software packages. As a result, he was able to to spend time determining the cause of the problems rather than getting tied up in the tedious and complex mathematical calculations.

Having established a benchmark nutrient level for each of the 12 lakes, Environment BOP is now using LakeWatch to keep an ongoing check on those levels. With LakeWatch , they can detect small changes in the trophic level and take appropriate remedial action before the consequences become disastrous and more expensive to fix.

Using LakeWatch, Environment BOP is now able to provide the community with information about the health of their lakes, so that they can better understand the effect their activities have on the local environment.

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