Homes have been evacuated in the Waitaki district overnight as flooding continues across the region.

Video posted on the Omarama Gazette Facebook page shows the Omarama Top 10 Holiday Park completely flooded out.

Some streets in Omarama are closed because of flooding from overwhelmed mud tanks.

Campervans have parked up in town and at the Omarama Community Hall, which is now a welfare centre.

Consumers on the Otematata and Omarama water supplies ave been advised to boil and conserve all drinking water until further notice.

This includes water used for food preparation and hygiene purposes such as brushing teeth.

Around 50 homes in parts of Canterbury are still without power according to Orion.

Environment Canterbury warns of high river levels across the region

Environment Canterbury said heavy rain has continued to fall along the main divide and across into some of the foothill river catchments overnight as anticipated.

Heavy rain is forecast to continue this morning, and then should begin easing and clearing away to the north throughout the day.

Along the divide, over 500 mm has been recorded at Mt Cook, 230 mm at Mistake Flats (Rangitata catchment), and 180 mm at Arthur Pass.

Further east, 66 mm has been recorded into the top of the Opuha River catchment at Clayton, and 94 mm into the top of the Ashburton River South Branch catchment at Boundary Creek.

Environment Canterbury said melting snow is likely to increase runoff and river flows beyond what might usually occur.

In South Canterbury, the Rangitata River is currently flowing at about 650 cumecs at the gorge.

Flows are expected to rise significantly higher today and may reach  1200 – 1500 cumecs later today.

Other rivers and streams originating from the main divide were high overnight and some caused localised flooding issues, particularly the Ahuriri, Omarama Stream, and Otematata River. These rivers will remain high through today.  

Some foothill rivers including the Orari, Opihi, Opuha, and Twizel, have risen during the night and are continuing to rise, however rainfall intensities are still relatively modest in these areas. The Opihi River is expected to stay within capacity today; however we are actively monitoring the river in the Milford Huts area.

A number of key State Highways have closed including SH6 Haast to Lake Hawea because of fallen trees, flooding and strong winds

SH8 Tarras to Twizel, SH83 Otematata, between Omarama and Kurow, SH94 Te Anau to Milford because of an avalanche hazard.

Fenz Omarama Fire Brigade volunteers clear blocked mud tanks in Totara Peak Cres, Omarama / Omarama Gazette