Linkwater is an area located between the Pelorus Sound/Te Hoiere and Queen Charlotte Sound/Tōtaranui. The hills are covered in native bush at higher altitude and production pine forest on the lower slopes. The river flats are predominantly grazed by dairy cattle. The three largest streams in the area are Cullen Creek, Linkwater Stream and Ada Creek. Cullen Creek and Linkwater Stream are both monitored as part of the State of the Environment programme. The results from this monitoring have shown that water quality is either degraded or at risk from degradation.
Trend analysis shows significant increases in nitrogen and E. coli concentrations in Linkwater Stream. Conversely, Linkwater Stream showed significant improvements in Total Phosphorus concentrations and turbidity.
