Site GY1 – Buller at

First draft May 2008: revised January 2009.

Site details

Hydrometric site number: 93203

Sampling Location: NZMS 260 K29: 015 295

Flow measurements: Measurements commenced July 29, 1963. Stage is measured 500m upstream from water quality sampling site and there are no major inflows between the recorder site and the sampling site. The recorder was originally located 50m downstream from the present site. The operational stilling well tower was installed in October 1980. The site is run by NIWA. The West Coast regional council runs telemetry from this site for flood warning. It is a very stable site with a good control. The river is gauged ~500m downstream from the recorder just downstream from GY1. Gaugings are carried out by boat: formerly with a current meters (Large Ott or Gurley, Amsler); and from 2003 to the present, with ADCP. The flow data are very reliable.

Sampling site: This site has remained in the same location since the inception of the NRWQN. Invertebrate sampling is carried out 5km downstream at a more suitable site with a faster flow. From 3 December 2008, the DO meter changed from the original YSI model 58 to the HACH Model HQ40d. The new meter employs a luminescent probe technology and stirring of the sample is not required to get a final, stable reading.

Catchment: The upstream catchment is predominately native bush with the remaining land use being farming. There have been no major changes in this catchment that are expected to affect water quality, although much of the pastoral land in the /Inangahua Valley and Murchison basin has undergone conversion to dairying. There may an increase in heavy metals caused by the hard rock mining at Reefton, but the change, if any, is expected to be virtually undetectable. Didymo has been discovered in this river and there have been blooms found in the location of the sampling and recording sites.

Site location

Buller @ Te Kuha Gauging Site Water level recorder site

GY1 Buller @ Te Kuha

Site photos and sampling/assessment details

Photo taken December 2007 looking downstream of the sampling site.

Photo taken December 2007 looking upstream of the sampling site.

River Flow

Periphyton transect (2) 10 Periphyton transect (1) 5 9 4 8 Black Disk 3

7 x 2 Sampling point 6 DO & Temperature 1

Photo taken April 2007. Note Rail bridge in background NW of sampling site.