Water has certainly been top of mind for the past several weeks. The seemingly unending rainfall and consequent rise in lake and river levels proved stressful and costly for the many property owners and businesses affected by flooding. For others, rain and rising water levels meant track closures that frustrated walking, cycling and other recreational activities. For many, the flood was more an enjoyable novelty, with photographers capturing scenic shots and children playing in the new Dinosaur ‘water park’.
On the whole, the response to the flooding appears to have been managed well. Lake Wānaka Tourism, Ignite Chamber of Commerce, Otago Regional Council (ORC) and Queenstown Lakes District Council (QLDC) shared information widely and provided frequent updates. ORC’s modelling of the predicted effects of rainfall kept the community informed about what to expect, giving businesses time to act, assisted by the many volunteers who turned out to help with sand bagging and moving inventory.
QLDC’s closure of the wastewater system on Ardmore Street minimised the risk that flood water might become contaminated by large volumes of human waste. QLDC continues to closely monitor reticulated drinking water to ensure that town water supplies remained safe to drink.
As flood waters start to recede and the weather improves, the community will recommence the recreational activities we normally enjoy at this time of year. After any heavy rainfall event, it is generally sensible to stay out of the water for at least a few days, particularly where the water is murky. The heavy rainfall just experienced will have flushed sediment, pathogens and contaminants from both rural and urban areas into our lakes and rivers.
Recreational water quality is monitored by the ORC at Roys Bay on Lake Wānaka and at the Lake Hāwea Holiday Park, with monitoring results published weekly on the LAWA website. At present, LAWA’s website offers no warnings about swimming in these lakes, other than stating “Water is generally safe for recreational activities in Lake Wānaka. However, bacterial contamination can occur, commonly after rainfall, as stormwater and rural run-off may contain human or animal effluent. In the Matukituki River flows above 45 cumecs generally indicate substantial rainfall has fallen in the catchment.” ORC’s monitoring reports that the Matukituki River was flowing at over 1,100 cumecs on December 3 and is presently flowing at 200 cumecs.
As the flood water recede and summer weather returns, care still needs to be taken as the usual walking, biking, swimming, boating and holiday camping areas will remain affected by flooding for several weeks to come.