Sixty-three per cent of HB rivers meet swimmable standards - report

The Tukituki River, pictured here near Red Bridge, is an area of focus for the Hawke's Bay Regional Council to improve water quality. Photo / File

A breakdown of the quality of the country's water bodies has ranked Hawke's Bay seventh among 16 regional council areas for the swimmability of its rivers.

The information was released in a Ministry for the Environment report last week, giving an update on work to improve water quality to meet the national targets for swimming.

These were to make 90 per cent of rivers and lakes suitable for primary contact by 2040, with 80 per cent swimmable by 2030, and for water quality to be improved overall.

In Hawke's Bay 63 per cent of rivers and 68 per cent of lakes were deemed swimmable.

The worst result came from Auckland where 23 per cent of rivers met the standards (97 per cent of lakes), followed by Northland at 24 per cent.

The best river quality was in Nelson at 100 per cent swimmable.

Across the country, 71.2 per cent of rivers and lakes were swimmable, the report said.

Each of the 16 regional councils had submitted progress reports on their activities to improve water quality and in Hawke's Bay it was noted that the main source of E.coli was ruminant - the likes of cattle, sheep and deer.

Information supplied by the Hawke's Bay Regional Council reported on efforts to address the problem in rural and urban areas, as well as point-source discharges.

The main point-source discharges were sewage from the Wairoa District Council and Central Hawke's Bay District Council, and wastewater from an Affco meatworks, the report said.

"Ongoing upgrades at Waipukurau and Waipawa are expected to overcome existing problems around capacity and design issues.

"Consent renewal discussions are currently under way for the Wairoa Affco discharge," the report said.

Stormwater treatment wetlands at Ahuriri Estuary are hoped to reduce E.coli by 80 per cent. Photo / File

Urban issues related to the Ahuriri Estuary and Purimu Stream where stormwater treatment wetlands were projected to reduce E.coli by 80 per cent, depending on the design, and Napier City Council was investigating options to increase the sewerage network capacity to prevent blow-outs during high-flow events.

In rural areas, attention to dairy effluent management would continue, the report said, with measures in place to ensure effective storage, conditions placed on all dairy consents, and farms visited and checked every year by compliance officers.

Work also included implementing the Tukituki plan from Plan Change 6, soil conservation control programmes, and a $1 million investment in improving water quality at five "hot-spots" - Lake Tutira, Ahuriri Estuary, Whakaki Lake and Wairoa River, Lake Whatuma and the Tukituki catchment, and Karamu Stream.

The report said that across the country the work to improve water quality was projected to improve overall swimmability of rivers and lakes to 78.1 per cent.

The cost of the nationwide committed improvements was estimated to be $217m per annum - $135m of which would be borne by the rural sector (based on two-wire fencing of waterways) and $82m by the urban sector.