Flooding updates: Rangitata River and Waitaki catchment area

Heres a wrap of this weeks updates from our flood team down in Timaru. Please keep an eye on our homepage and our Facebook page for ongoing flood alerts and the latest information on the situation.

Friday, 20 December 2019

These updates are as at 11am on Friday, on river works at the Rangitata and in the Waitaki lakes and rivers, where water levels are still high. 

The photo above shows the Rangitata River south branch channel late last week.

Rangitata River

As a result of Thursday night's rain, the Rangitata River peaked at the gorge at the flow of 370 cumecs at 9.35 am this morning. This high flow will move down the river system today and we expect this to arrive at the State Highway 1 bridge mid-afternoon.

Environment Canterbury does not expect there to be any significant out of river flows as a result of these higher river levels.

Farmers are still advised to monitor their own situation closely.

Heavy machinery operators, using large bulldozers and diggers will continue working throughout the week to strengthen flood protection works in the Rangitata River at several key locations, including strengthening the Ferry Road bank above Arundel, and working in the river above State Highway 1 and the railway line.

The flood protection river works are still in a vulnerable state and changes in flow and flow paths could result in break outs onto adjacent farm land. While improvements are occurring, works to restore flood protection will take much longer (weeks to months).

Upper Waitaki Catchment

River flows connecting the hydro lakes are high. Genesis Energy is spilling from Lake Tekapo via Lake George Scott into the Tekapo River. Flows of about 180 cumecs are flowing down the Tekapo River. Similar flows are expected to continue over the next few days. Flows may change rapidly. Public are advised to keep away from this river system.

Meridian Energy is spilling down the Pukaki River and this is expected to continue for the rest of the week. Public are advised to keep away from this river system.

Water levels around lakes remain high.  Campers should stay well away from river and lake edges.

These messages will be updated when the situation changes.

Previous flooding updates

Thursday, 19 December 2019
These updates were as at 10am Thursday.

Rangitata River

The Rangitata River is currently flowing at 215 cumecs at the gorge recorder.

A warning for heavy rain in the catchment from 3pm Thursday 19 December until 2am Friday has been issued by the Metservice. The river will rise from early Friday as a result of this rain.

Farmers are advised to monitor their own situation closely as changes in the river could cause overflows onto farmland.

Heavy machinery operators, using large bulldozers and diggers will continue working throughout the week to strengthen flood protection works in the Rangitata River at several key locations, including strengthening the Ferry Road bank above Arundel, and working in the river above State Highway 1 and the railway line.

The flood protection river works are still in a vulnerable state and changes in flow and flow paths could result in break outs onto adjacent farm land. While improvements are occurring, works to restore flood protection will take much longer (weeks to months).

Upper Waitaki Catchment

River flows connecting the hydro lakes are high. Genesis Energy is spilling from Lake Tekapo via Lake George Scott into the Tekapo River. Flows of about 180 cumecs are flowing down the Tekapo River. Similar flows are expected to continue over the next few days. Flows may change rapidly. Public are advised to keep away from this river system.

Meridian Energy is spilling down the Pukaki River and this is expected to continue for the rest of the week. Public are advised to keep away from this river system.

Water levels around lakes remain high.  Campers should stay well away from river and lake edges.

Wednesday, 18 December 2019
These updates were as at 12.30pm Wednesday.

Rangitata River

The Rangitata River is currently flowing at 260 cumecs at the gorge recorder.

Heavy machinery operators, using large bulldozers and diggers will continue working throughout the week to strengthen flood protection works in the Rangitata River at several key locations, including strengthening the Ferry Road bank above Arundel, and working in the river above State Highway 1 and the railway line.

Over the weekend, flows were diverted away from the entry to the south branch channel. There is seepage into the channel and a small amount of water is still present.

A warning for heavy rain in the catchment starting at 3pm Thursday 19th December has been issued by the Metservice. The river will rise on Friday as a result of this rain. More details will be posted here by midday Thursday.

Farmers are still advised to monitor their own situation closely as changes in the river could occur.

The flood protection river works are still in a vulnerable state and changes in flow and flow paths could result in break outs onto adjacent farm land. While improvements are occurring, works to restore flood protection will take much longer (weeks to months).

Upper Waitaki Catchment

River flows connecting the hydro lakes are high. Genesis Energy is spilling from Lake Tekapo via Lake George Scott into the Tekapo River.  Flows of about 180 cumecs are flowing down the Tekapo River. Similar flows are expected to continue over the next few days. Flows may change rapidly.  Public are advised to keep away from this river system. 

Meridian Energy is spilling down the Pukaki River and this is expected to continue for the rest of the week. Public are advised to keep away from this river system. 

Water levels around lakes remain high.  Campers should stay well away from river and lake edges.

Tuesday, 17 December 2019
These updates were as at 11.30am Tuesday.
Rangitata River

The Rangitata River is currently flowing at 226 cumecs at the gorge recorder.

Heavy machinery operators, using large bulldozers and diggers will continue working throughout the week to strengthen flood protection works in the Rangitata River at several key locations, including strengthening the Ferry Road bank above Arundel, and working in the river above State Highway 1 and the railway line.

Over the weekend, flows were diverted away from the entry to the south branch channel. There is seepage into the channel and a small amount of water is still present.

Some rain is currently falling in the Rangitata catchment, the forecast is for a further 30-40 mm rain in the catchment up to 6 am Wednesday. We expect some increase in flows but at this stage the flood protection works should contain anticipated increases in river flows. Farmers are still advised to monitor their own situation closely as changes in the river could occur.

The flood protection river works are in a vulnerable state and changes in flow and flow paths could still result in break outs onto adjacent farm land. While improvements are occurring, works to restore flood protection will take much longer (weeks to months).

For more on road closures and other information, please visit Timaru District Council's website.

Lower Waitaki River

As a result of very heavy rainfall in the alpine catchments feeding the Waitaki hydro lakes, spill flows are occurring at all hydro dams and spillways.

The flow in the Waitaki River below the Waitaki Dam is currently 850 cumecs and similar flows are expected to continue through this week.

Given the prolonged period of higher flows, erosion of river margins is likely to occur in places. Sustained high flows may result in some outflows pushing into established swales on farmland. Farmers are advised to check their river frontages and keep a close watch on low lying areas.

Upper Waitaki catchment

River flows connecting the hydro lakes are high. Genesis Energy is spilling from Lake Tekapo via Lake George Scott into the Tekapo River. Flows of about 170 cumecs are flowing down the Tekapo River. Similar flows are expected to continue over the next few days. Flows may change rapidly. Public are advised to keep away from this river system.

Meridian Energy is spilling down the Pukaki River and this is expected to continue for the rest of the week. Public are advised to keep away from this river system.

Water levels around lakes remain high. Campers should stay well away from river and lake edges.

Monday, 16 December 2019
These updates were as at 12 noon Monday.

Rangitata River

The Rangitata River is flowing at 210 cumecs at the gorge recorder.

Heavy machinery operators, using large bulldozers and diggers, worked over the weekend and will continue throughout the week ahead to strengthen flood protection works in the Rangitata River at several key locations, including above Arundel, above State Highway 1 and the railway line, and at the south branch entry.

Over the weekend, flows were diverted away from the entry to the south branch channel. There is seepage into the channel and a small amount of water is still flowing.

Some rain is forecast in the Rangitata catchment for Tuesday and farmers are advised to monitor their own situation closely as changes in the river could still occur.

The flood protection river works are in a vulnerable state and changes in flow and flow paths could still result in break outs onto adjacent farm land. While improvements will slowly occur, works to restore flood protection will take much longer (weeks to months).

For more on road closures, please visit Timaru District Council's website.

Lower Waitaki River

As a result of very heavy rainfall in the alpine catchments feeding the Waitaki hydro lakes, spill flows are occurring at all hydro dams and spillways.

The flow in the Waitaki River below the Waitaki Dam is currently 940 cumecs and similar flows are expected to continue through this week.

Given the prolonged period of higher flows, erosion of river margins is likely to occur in places. Sustained high flows may result in some outflows pushing into established swales on farmland. Farmers are advised to check their river frontages and keep a close watch on low lying areas.

Upper Waitaki catchment

River flows connecting the hydro lakes are high. Genesis Energy is spilling from Lake Tekapo via Lake George Scott into the Tekapo River. Flows of about 170-190 cumecs are flowing down the Tekapo River. Similar flows are expected to continue over the next few days. Flows may change rapidly. Public are advised to keep away from this river system.

Meridian Energy is spilling 270 cumecs down the Pukaki River and this is expected to continue for the rest of the week. Public are advised to keep away from this river system.

The Ohau weir is no longer overflowing but this could change as a result of forecast rain.

Water levels around lakes remain high. Campers should stay well away from river and lake edges.

Further information

https://ecan.govt.nz/data/riverflow/
https://ecan.govt.nz/data/rainfall-data/

For more on road closures please visit Timaru District Council's website.