The SFR Grade gives an overall measure of the recreational water quality of a site. It is based on the concentration of indicator bacteria that were measured over five consecutive summers at a site. An assessment of potential sources of contamination that could impact the water quality of a site is also part of the process of assigning an SFR Grade.
There are five SFR Grades ranging from very good to very poor. The table below shows the grades and their meaning.
|Very Good||Considered satisfactory for swimming at all times.|
|Good||Satisfactory for swimming most of the time with exceptions following rainfall.|
|Fair||Generally satisfactory for swimming. Caution should be taken during periods of high rainfall and swimming avoided if water is discoloured.|
|Poor||Swimming should be avoided, particularly by the very young, the very old and those with compromised immunity.|
|Very Poor||Generally swimming is not recommended.|
The SFR Grades are reviewed every two to three years. A site has to be monitored for a minimum of five summers before an SFR Grade can be assigned. However, if only one year is missing, an interim SFR Grade can be assigned. The table below shows the current SFR Grades. Sites marked with two asterisks (**) have interim SFR Grades.
(Sanitary Inspection Category)
(microbiological Assessment Category)
(Suitability for Contact Recreation Grade)
|Moetapu Bay||Insufficient data|
|Waikutakuta/Robin Hood Bay East**||Very Low||B||Very Good|
|Waikutakuta/Robin Hood Bay West**||Low||B||Good|
|Pukatea/Whites Bay||Very Low||A||Very Good|
|Marfells Beach||Very Low||A||Very Good|
|Rai River at Rai Falls||Moderate||D||Poor|
|Te Hoiere/Pelorus River at Pelorus Bridge||Low||B||Good|
|Te Hoiere/Pelorus River at Totara Flat||Moderate||C||Fair|
|Wairau River at State Highway 6**||Moderate||C||Fair|
|Wairau River at Ferry Bridge||Moderate||C||Fair|
|Wairau River at Blenheim Rowing Club||Moderate||B||Good|
|Taylor River at Riverside||High||D||Very Poor|
|Ōpaoa River at Elizabeth Street Bridge||Moderate||C||Fair|
|Waihopai River at Craiglochart #2||Moderate||C||Poor|
The MAC is calculated as the upper 95th percentile of indicator bacteria concentrations over five consecutive summer seasons.
Council uses the ‘BatheWatch’ software provided by the Ministry for the Environment to assign SFR Grades.
A cost-effective approach to measuring the concentration of microorganisms that could affect the health of swimmers is the use of indicator bacteria.