This message was posted on Thursday 20 June 2013 at 9am.

Rainfall situation

Up to 130mm of rain fell in the South Canterbury and Waitaki Valley foothills and plains from early Sunday 16 June to late Monday.
All foothill rivers in the area peaked on Monday afternoon and flows have dropped.

ECan staff are assessing the damage to the river systems and stopbanks. Stopbank breaches on the Lower Waihao River have reduced considerably the flood carrying capacity of this river. Other rivers may also have suffered damage.

Overnight Wednesday (19th) and into Thursday (20th) some rain has continued to fall in South Canterbury with most coastal raingauges recording between 15mm - 40mm. This rain has been steady but with only low to moderate intensity. Further back in the catchments (above 200 - 300m elevation) this precipitation is mostly falling as snow.

Due to the saturated ground conditions, the continuing rainfall will cause rapid increases in the flows of small streams, creeks and drains on the plains as well as general ponding in lower lying areas. Water on roads and their margins will also be common and motorists need to take care.

The presence of snow higher in the catchments should limit the flows of the larger foothill rivers and ECan doesn't anticipate any problems with flooding from these rivers, but all farmers adjacent to rivers are advised to continue to check their own situation as even modest amounts of rain, in the lower catchment may result in a some rise in river levels.

Coastal Swell Warning

The metservice has also issued a swell warning for the coastal area from the Waitaki River to Banks Peninsula. The forecast is for southerly swells up to 5m overnight Thursday/Friday with high swells continuing through the weekend. These swells coincide with a period of higher then usual high tides (perigean tides). Landowners adjacent to the coast need to monitor their situation and stock or equipment in low-lying coastal areas should be moved.

High tide times over the weekend are: Friday 0030hrs & 1300 hrs. Saturday 01:30hrs and 1400hrs and Sunday 0220hrs & 1450hrs.

This message will updated if the situation changes significantly.

Website links:

http://ecan.govt.nz/services/online-services/monitoring/river-flows/Pages/River-flows-south.aspx

http://ecan.govt.nz/services/online-services/monitoring/rainfall/Pages/rainfall-south-canterbury.aspx