Permits required for Mararoa and Waiau rivers February 11th, 2020 2005-08-19T08:52:00+12:00 Biosecurity NZ has issued a Controlled Area Notice over the Mararoa and Waiau rivers in Southland to control the further spread of Didymosphenia geminata (Didymo). This means that from August 19 a permit is required before kayaking on these rivers, including at Kiwiburn. According to BNZ’s media release, the best protection is to avoid the rivers altogether. The next best is to dedicate equipment specifically for use only in the affected rivers. The third is to use the approved cleaning methods on your equipment afterwards.