1 / 30

Water Quality – Lake Waikare

Water Quality – Lake Waikare. Presentation to Waikato District Council 24 June 2014. Presentation outline. Context - Lake Waikare and surrounding catchment Lake Waikare water quality challenge Existing governance arrangements Future. Lake Waikare Context.

wclaude
Download Presentation

Water Quality – Lake Waikare

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Water Quality – Lake Waikare Presentation to Waikato District Council 24 June 2014

  2. Presentation outline • Context - Lake Waikare and surrounding catchment • Lake Waikare water quality challenge • Existing governance arrangements • Future

  3. Lake Waikare Context • One of many shallow lowland peat lakes in the Waikato delta • Lower Waikato Flood Protection scheme • Area of significance for Waikato-Tainui • Whangamarino wetland • Catchment land use and sedimentation • Shallow lakes accord (Waikato-Tainui, WDC, DoC, WRC)

  4. 35 Lower Waikato Lakes 28 21 • 25 lakes in the Lower Waikato zone • 3 provisionally ranked in Top 10 Waipa/Waikato/ Hamilton lakes • Lakes Rotokawau(3), Areare (9) and Waahi(10) 16 3 38 11 42 40 10 9 13

  5. Lake Waikare Context • A shallow lake, high sediment input • Flood control scheme lake level storage and management • Large sediment inflow from Matahuru catchment • Downstream impacts of sediment through the wetland • Current Waikare gate consent compliance review • Other consents to discharge to Lake Waikare

  6. Rangiriri Spillway & 1971 when in operation

  7. Lower Waikato Flood Protection Scheme

  8. Lower Waikato Zone

  9. Lake Waikare water quality • Nitrogen, phosphorus – promote algal growth • Sediment (reduced clarity impacts ecology and suitability for contact recreation) • Wind and pest fish disturb bottom sediments

  10. Monoraphidium sp. Red pigment “zeaxanthin”

  11. Water quality in some shallow lakes 2008-12

  12. Estimated phosphorus loads from lakes’ catchments

  13. Lake Waikare, P concentrations 1996-2014

  14. Matahuru Catchment • Soil stability • 65% of catchment unstable • evidence of past erosionon hill slopes • Erosion mainly landslides, gully erosion and stream bank erosion • Soil Conservation • Present on 4337 ha (42%) of catchment • Absent and required on 1340 ha (13%) • Upgrades to conservation required on 1445 ha (14%)

  15. Matahuru Catchment

  16. Matahuru Catchment

  17. Existing Governance Arrangements

  18. Land administered by DOC, WRC & Waikato –Tainui in the vicinity of Lake Waikare & Whangamarino Wetland

  19. Land Ownership • Lake bed owners – Waikato-Tainui • Mixed ownership of lake margins (Fish and Game, DoC, local Iwi, WRC, WDC, private) • Remainder of catchment upstream (mainly private) • Remainder of catchment downstream (DoC, Fish and Game, private)

  20. Governance Arrangements • Waikato District Council • Land use planning • Consent to discharge (Te Kauwhata waste water) • Waikato Regional Council • RMA - Effects of land use, Healthy Rivers – WaiOra, Water allocation V6 • Lower Waikato Liaison subcommittee • Lower Waikato Flood Protection Scheme and associated consents • Project Watershed – Integrated catchment management • Co-management (JMAs and co-managed lands)

  21. Governance Arrangements • Joint management • Co-management • Waikato District Lakes Memorandum of Agreement • Waikato Tainui • Co-governors and owners of lake bed • Co-managed lands / Sites of significance • DoC • Wetland and Biodiversity management • Fish and Game • Wetland and game bird management

  22. Future • Management of upper catchment (soil conservation and water quality) • Scale of issues major impediment to in-lake restoration • Habitat enhancement of margins – ephemeral wetlands • Management of lake depth – WQ/sediment re-suspension, irrigation • Plant pest management (yellow flag, alligator weed)

  23. Future • Management of the flood protection scheme • Local -1500 ha surrounding lake • Regional – 17,000 ha protected land • National infrastructure – SH1 protection • Lake Waikare an important part of the scheme • Challenge: • Maintaining viable flood protection scheme • Improving lake water quality • Protecting biodiversity • Managing future demands for water • All parties to act effectively towards a common goal

  24. WRC Future Actions • Consent review Lower Waikato Flood Control Scheme • Lake Waikare discharge • Impacts on Whangamarino wetland • Long Term Plan 2015-25 • Detailed assessment of high risk/opportunity sites in the zone • Project management for inter-agency catchment plan • Additional catchment management staff and incentives

More Related