Coastal Manawatu - Horowhenua

The Coastal Manawatū-Horowhenua sub-catchment:

  • is 57,000ha in area,
  • land use is 37% sheep and beef, 36% dairy, 21% forest (native and exotic), 1% urban,
  • has a number of popular swimming spots, including the Mangahao Whitewater Park,
  • contains historic Rangitāne O Manawatū customary fishery areas throughout, along with mahinga kai, and kāinga sites and wāhi tapu,
  • Since the 1820’s, and prior to the signing of Te Tiriti O Waitangi, Ngāti Toarangatira and Ngāti Raukawa Iwi have maintained a strong traditional, environmental and cultural responsibility for the lower reaches of the Manawatū River, out into the ocean and southwards (known as te au ki te tonga) towards Ōhau, Ōtaki, Te Horo and Waikanae. Areas of interests, by virtue of land ownership to various hapū and Iwi O Ngāti Raukawa, include specific ROM customary fisheries including
    • Ōmarupapako Reserve,
    • Moutoa Wetland,
    • Foxton River loop / Motukarapa reserve, and
    • Manawatū estuary and feeder creeks and streams,
  • has ten sites of rare/threatened native fish, including Koputaroa Stream which is a regional native fish hot-spot, and supports a locally important whitebait and tuna fishery,
  • is an important trout fishery and spawning area,
  • contains 35 high priority bush and 14 high priority wetland sites, including Manawatū Estuary (a wetland of International Importance), and
  • includes parts of the Lower Manawatū scheme, and the Makerua, Moutoa, Koputaroa, Foxton East, and Whirokino Drainage schemes.

The water quality of the Lower Manawatū subcatchment is characterised by high suspended sediment loads, and high phosphate and nitrate levels. The sediment load is contributed from higher in the catchment, and the high nutrient levels are a combination of inputs from the upper part of the Manawatū Catchment, as well as non-point and point source inputs from within this sub-catchment. Water quality is also heavily influenced by tides. Pathogen levels in the main stem of the river during

THE WATER QUALITY STATE IS EXPLAINED BY:

  • this sub-catchment contains less than 900ha of unprotected erosion prone land and is contributing a very low amount of the total suspended sediment load to the Manawatū Catchment,
  • there are 29 consented discharges to water in the sub-catchment, four of which are considered significant. These are: Tokomaru sewage, Shannon sewage, Foxton sewage, and the Silver Fern Farms Shannon Fellmongery. Applications for consent for Shannon sewage is currently being considered through the consent process. The discharges from Silver Fern Farms Fellmongery and Foxton sewage were reconsented in 2008. The compliance rate of the discharges monitored is 96%,
  • there are 111 consented dairy shed effluent discharge consents, all of which are discharges to land. Compliance assessments for these consents will be completed by the end of the season, and
  • the exact level of progress towards the Dairying and Clean Stream Accord targets (around stock exclusion from waterways, stock crossing, and nutrient management) by dairy farmers in this sub-catchment is unknown, but there is extensive riparian fencing and  planting, and stock crossings (bridges and culverts). Farmer surveys in the Manawatū-Whanganui region indicate the majority of Dairying and Clean Stream Accord targets are achieved.

IN ADDITION:

  • 9 man-made barriers are having a moderate to high impact on native fish migration. According to local Iwi O Ngāti Raukawa, there are a number of structures with a moderate to high potential to restrict fish passage upstream,
  • the whitebait and tuna harvest have declined markedly in the last 20 years,
  • public access to the Manawatū River and its tributaries is limited,
  • only 12% of high priority bush remnants and 43% of high priority wetlands are protected, and
  • the water quantity resource of the Coastal Manawatū-Horowhenua sub-catchment is 65% allocated. All major takes are metered and automatically monitored.

REDUCE THE IMPACT OF FLOOD CONTROL AND DRAINAGE SCHEMES BY:

  • making greater use of plants on river banks
  • meeting resource consent conditions, compliance monitoring and enforcement
  • ensuring all works are undertaken in accordance with Codes of Practice

PREVENT OVER USE OF WATER BY:

  • ensuring metering of all major water takes
  • meeting resource consent conditions, compliance monitoring and enforcement
  • ensuring consented takes meet regional standards

REDUCE THE NUTRIENT AND BACTERIA FROM POINT SOURCE DISCHARGES THROUGH:

  • requiring resource consents for stormwater discharges
  • meeting resource consent conditions, compliance monitoring and enforcement
  • ensuring discharges meet regional water quality standards
  • resolving outstanding resource consent applications

REDUCE THE RUN-OFF OF SEDIMENT, NUTRIENTS AND BACTERIA FROM INTENSIVE LAND-USE SUCH AS DAIRYING AND CROPPING THROUGH:

  • adoption of Nutrient Management Plans and promotion of nutrient use efficiency
  • achieving the Dairying and Clean Streams Accord targets
  • meeting resource consent conditions, compliance monitoring and enforcement

PROTECT AREAS OF HABITAT FOR NATIVE FISH, BIRDS AND TROUT BY:

  • meeting resource consent conditions, compliance monitoring and enforcement
  • removing fish barriers
  • fencing and planting streams and bush/wetland areas, and pest control