The COP 26 conference (the United Nations climate change conference, 26th conference of parties thus COP26) highlighted ways we woud see climate change. Significant floods and significant droughts feature and both could impact on this area. The Tongariro River Catchment”s last significant flood was 2004.
After the floods of 1988 and 2004 it took significant effort to get action to clean up the consequences of the flood. Waikato Regional Council (WRC) took control. Since then WRC staff have done a good job in developing a flood protection scheme for Turangi and maintenance of the scheme has been on going until the last couple of years.
I am simply asking if the work done since 2011 still being maintained?
Fortunately we have kept on our website in Key documents the Annual Work Plans since 2011 and I have picked quotes from them. My copying does not replicate the original as well as I woud have liked but I invite you to read the annual work plans on our website.
Annual Works Programme
Introduction Waikato Regional Council maintains and operates a flood protection scheme on the Tongariro River. The scheme is designed to protect the Turangi community from a 1 in 100-year event. Continued monitoring and maintenance of assets, floodway and main channels is required to ensure the scheme operates to design standards.
In 2011, Resource consents were granted to the Waikato Regional Councilâ€™s Integrated Catchment Services directorate (ICM) for the management of the river floodway and flood protection scheme. These consents are summarized as follows:
RC # Activity authorised
121305 Erosion control/flood protection works: gravel extraction up to 150,000cum/year, erosion control works and vegetation removal, temporary diversion bunds and culvert crossings.
121306 Divert water and temporarily dam and divert water within the Tongariro River.
From the 2016-17 River Works programme
184.108.40.206 Riparian Native Planting Condition 37 (e) of the consent relates to consulting on any proposed riparian planting. Riparian management throughout the scheme includes targeting pest plant species which threaten to invade and dominate in this environment. Native low growing species such as carex sp. and toi toi will be encouraged to establish throughout the scheme. These are largely self sown. Previous native planting along stopbanks will continue to be maintained, with weed species (particularly broom and gorse) being controlled. Ngati Turangitukua will be included in the planning of any future native revegetation programmes.
5.2 Tongariro River vegetation management Vegetation control throughout the flood scheme is to continue in the 2016/17 works season. Low growing vegetation or grass varieties are the preferred species for ground cover within the floodway. This vegetation cover requires continued management to control and eliminate woody weed species such as willow, pine and broom. These denser plant varieties can threaten a flood scheme as they can restrict flood flows or block channels.
Annual Works Plan 2018
Description and Nature of Works Scheduled works during the 2018 season will primarily involve gravel island vegetation control, and gravel management. Vegetation clearance of certain gravel islands and gravel management at specific locations are considered the most appropriate strategies to maintain the design standards of the Tongariro flood management scheme. Other works may include stopbank maintenance, bank revegetation and de-vegetation (generally permitted activities).
2020 Work plan
Vegetation Management There is a requirement for ongoing management of woody species on assets and within the floodway. Recent and increased growth throughout the floodway is contributing to: Â· Decreased capacity through combined mass. Â· Promoting gravel island build up, decreasing capacity and increasing channel instability. Â· Reduced native/natural ecosystem and habitat. Â· Limiting recreational opportunity. Â· Increasing debris build-up potential during/after high flow events. It is important that vegetation is managed annually to ensure invasive species do not become dominant and uncontrollable. Vegetation management objectives within the floodway align well with other stakeholder aspirations and a collaborative approach will be sought.
The Covid19 pandemic has caused issues among which have been restrictions on movement, difficulty in finding a workforce in many areas resulting in work not being done.
There has been no gravel extraction resulting in stream bed aggradation (the river bed rising and increasing the risk of flooding). Woody vegetation of pines, broom and willow which also increase risk of flooding through narrowing the river channel.
I mentioned in a previous blog our concern with gorse and with it the broom is getting woody and tall. The beach at the Reed is now covered in emerging willows and broom.
The river also hs much tree debris in it which causes a build up in the river bed.
Floods in themselves are natural and cleanse te river. It is the 1 in 100 year flood that is the concern and the warning from COP26 is that we should expect these extreme events.
Thank you for your continued support. It has been a strange couple of years. As a local we have had some unpressured fishing in what has been a very good year not that I participated often.
Our Treasurer has asked for this subscription reminder to be included in this blog.
AND, last but not least, just a friendly reminder to renew your subs for 2021 if you havenâ€™t already done so. There is no need to fill out the membership form if you are just repeating last yearâ€™s subs/donations. This is only required if there are any changes to your contact details – in which case either fill in the active pdf attached and return by email or go to the website – http://www.tongariroriver.org.nz/membership/ – and complete the form there. It is a good idea to keep a copy of the receipt we send, just as a record for the current year. A pdf of the subs form is attached for your own records if more convenient.
Please pay by direct credit to our bank account: 38 9000 0863130 00 Advocates Tongariro River
Donations still make up a very important part of our income so any amount you may also feel inclined to part with will be greatly appreciated.
Many thanks and tight lines!
John Toogood Treasurer.
Iwish you all a Merry Christmas and a happy New year and for you all to be included in the experience of the wonders of the Tongariro River Catchment in 2022.