Flows in the Lower Waitaki River, downstream of the Waitaki Dam, are expected to run at around 1400 cubic metres per second (cumecs) until around 6 pm tonight. This is about four times the normal flow.
“Flows are expected to reduce to about 1100 cumecs later this evening,” said Environment Canterbury duty flood controller Philip Lees. “High flows about this level may continue for a further day or two.
“People need to be reminded that these flows are taken at the recorder at Kurow and changes to these flows take approximately 10 hours to reach the coast.
“No further rainfall has affected the catchment in the last couple of days, so flows are not expected at this stage to increase beyond this level. Environment Canterbury staff have been monitoring key locations along the river and have reported no significant problems. We advised farmers in the Lower Waitaki River earlier in the week to shift stock from low-lying areas.”
Following large amounts of rain in the main divide earlier this week, Meridian Energy released water from the hydro lakes in the Upper Waitaki River, significantly boosting normal flow levels. ECan will continue working closely with Meridian to monitor the situation carefully, Phil Lees said.
This weekend is the beginning of duck-shooting season, so duck-shooters need to take care when using the river, particularly if they are entering the river area in the dark.
“I recommend duck shooters check the ECan website before they head out. Flood warnings are on the home page, and river levels are all available. This way at least they will have some idea of how high the river will be,” he said.
Other alpine-fed rivers had also risen this week but had fallen in the past day or so.
For further information: Philip Lees, ECan flood controller 03 6877 868 or 0274 986 742, flood warnings on www.ecan.govt.nz , river levels from the home page right hand side or www.ecan.govt.nz/Our+Environment/Water/Rivers/RiverFlows/river-flow-table.htm.
ALGAL WARNING
In addition to the high river level warning in the Waitaki River, hunters and fishermen are reminded that warnings of toxic algal blooms in rivers and lakes remain in place in some areas of Canterbury. Eating or licking algal mats can be lethal for dogs and stock.
Kaikoura
An algal bloom is present in Lake Rotorua, and people and animals should avoid contact with the lake water.
North Canterbury
High flows in the Hurunui and Waiau rivers will have removed the toxic Phormidium algae. However, warnings remain in place for the Selwyn River and Ashley River. River users are advised to keep dogs out of these rivers.
Banks Peninsula
The toxic algae Nodularia is still present in Lake Ellesmere/Te Waihora and Lake Forsyth/Wairewa. People and dogs should keep out of areas where there are scums or foams on the lake shore, and when the water is bright green or blue-green.
South Canterbury
Phormidium is present in the Opihi River from at least Hanging Rock and further downstream.
In other areas toxic algae may be present in rivers or ponds, and people should avoid any areas where there are thick algal growths (dark brown/black mats in rivers - or bright green or red scums in lakes and ponds).
Visit Environment Canterbury's website for more information on what the algae looks like: www.ecan.govt.nz/Our+Environment/Water/SwimmingWaterQuality/ToxicAlgae.htm
Further information: Shirley Hayward, ECan Surface Water Quality Scientist, 03 372 7055, shirley.hayward@ecan.govt.nz