Risk assessment method for submerged weeds in New Zealand hydroelectric lakes

  • J. Clayton
  • P. Champion
Part of the Developments in Hydrobiology book series (DIHY, volume 190)


The latent potential for problematic weed growth in a hydro-lake is proportional to water level fluctuation, water clarity, lake shape, littoral gradient and exposure to wave action. These five factors were used to assess a score for measuring the latent potential for weed impact and each factor was allocated a score of 1–5, with a theoretical maximum of 25. Any hydro-lake scoring above 15 could be expected to present potential inconvenience to power generation, given the presence of suitable submerged weed species. Assessment of potential impact arising from weed invasion must firstly determine what species are already established, and whether it is possible for a weed species of greater potential impact to be introduced. The risk of this occurring is dependent upon a number of factors, including public accessibility, proximity to sources of those species and the desirability of the waterbody to potential weed vectors. Once these factors are quantified, appropriate surveillance strategies in high-risk hydro-lakes may then be developed.

Key words

aquatic plants weed potential risk assessment weed management 


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Copyright information

© Springer 2006

Authors and Affiliations

  • J. Clayton
    • 1
  • P. Champion
    • 1
  1. 1.National Institute of Water and Atmospheric ResearchHamiltonNew Zealand

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