The Middle Manawatū sub-catchment:
- is approximately 17,000ha in area,
- land use is 58% sheep and beef, 18% forest (native and exotic), 5% urban, and 14% dairy,
- has a number of popular swimming spots,
- has a significant number of Rangitāne O Manawatū wāhi tapu and customary fisheries sites, and contains many of Rangitāne O Manawatū historic aqua-cultural fisheries sites and mahinga kai sites, including Parahaki Island at the entrance to the Manawatū Gorge by
the township of Ashhurst which also contains Rangitane O Tamaki Nui A Rua wahi tapu and sites of significance,
- has two sites of rare/threatened native fish,
- is an important trout fishery,
- contains 2 high priority bush and 1 high priority wetland sites, and
- includes parts of the Lower Manawatū scheme and Ashhurst drainage scheme.
The water quality of the Middle Manawatū subcatchment is characterised by high suspended sediment loads, and high phosphate and nitrate levels. However, these issues are mostly inherited from those sub-catchments located further upstream. Generally, water quality improves through this reach. Pathogen levels are generally safe for swimming. Point source discharges contribute the greatest loading during low flow conditions, when run-off from land is significantly reduced.
THE WATER QUALITY STATE IS EXPLAINED BY:
- this sub-catchment contains approximately 170ha of unprotected erosion prone land and is contributing a very low amount of the total suspended sediment load to the Manawatū Catchment,
- there are 11 consented discharges to water in the sub-catchment, two of which are considered significant. These are: Ashhurst sewage and Aokautere sewage. Aokautere sewage is working towards connecting to the Palmerston North Waste Water Treatment
Plant in the next 12 months, and Ashhurst sewage requires a new consent in 2013. The compliance rate of the discharges monitored is 100%,
- there are 7 consented dairy shed effluent discharge consents, all of which are discharges to land. The compliance rate for these consents so far this season is 94%, 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.
- 2 man-made barriers are having a moderate to high impact on native fish migration,
- public access to the Manawatū River is limited except in the built-up Palmerston North area,
- all high priority bush remnants and wetlands in this sub-catchment are protected, and
- the water quantity resource of the Middle Manawatū sub-catchment is 79% allocated. All major takes are metered and automatically monitored.