Rivers shrink as rainfall stays away
1 December 2010 - Two consecutive months of low rainfall have left most Taranaki rivers and streams at low levels not
usually seen until mid-summer, and some are at the lowest ever recorded at this time of year.
The Taranaki Regional Council says a few pasture irrigators have already had to stop taking water, and the situation is
being closely monitored.
"We have a well-established set of procedures to follow when water shortages occur, and we liaise directly with
individual water-take consent holders," says the Council's Director-Resource Management, Fred McLay.
"While September was very wet, we're very concerned that the lack of rainfall in October and November has left rivers so
low at such an early stage of the summer," he says. "October is traditionally one of the wetter months in Taranaki, but
this time rainfall was between 20% and 50% of normal. November was even drier in places, with between 12% and 50% of
normal.
(See graph - click on it for large version.)
Click for big version
"Most of the rivers we monitor are already at their mean annual low flow (MALF) - we don't normally expect to see that
until late January or early February."
The Waitara and Manganui Rivers are at the lowest levels ever recorded for November, partly reflecting dry conditions in
the eastern hill country where the Waitara River rises.
"Some areas are more impacted than others," says Mr McLay. "Besides the eastern hill country, the south of South
Taranaki and the north of North Taranaki are feeling the brunt. It's not so bad closer to the mountain."
The Taranaki Regional Council monitors rainfall at 25 sites and river levels at 22 sites around the region, with data
relayed to its hydrology staff via telemetry links. "So we're constantly monitoring what's happening and can step in to
reduce water takes as soon as the situation demands," says Mr McLay.
Rainfall and river-level data from many of the monitored sites are also published live on the Council website, www.trc.govt.nz, along with maps showing monthly and year-to-date rainfall at monitored sites.
ENDS