Archive for 2012

Lake Level – update May 14th, 2012

The lake is closed to the sea. The average  level of the lake as recorded on Friday May 11th was 1.06m.

The level at which an opening can be considered at this time of year is 1.13m above mean sea level.

The graph below is a summary of lake level and openings for 2011, to mid December.


To:
M
Customer Services
Thursday, 11 August 2011 9:50 a.m.

Good morning to you all,
The lake is closed to the sea. The average level of the lake as recorded Wednesday 10 August was 1.02m.
The lake was opened to the sea on Thursday 4th August at a level of 1.17m and closed naturally on Tuesday 9th August.
The level at which an opening is considered at this time of year is 1.05m.

Longfin eels in Te Waihora/Lake Ellesmere

Recent publicity has higlighted the plight of longfin eels, which are unique to New Zealand and are listed as a threatened species.

Clausen-eels-Jack-Vince-Dave-Vince-1947 Te Waihora/Lake Ellesmere maintains important customary and commercial tuna (eel) fisheries. Two species, shortfins and longfins, are present and there is evidence to suggest that the proportion of longfins has declined over time. A NIWA report, prepared for ECan in 2010, provides details of the tuna populations in the lake and tributaries.

In light of the decreased abundance of longfins in the Te Waihora/Lake Ellesmere, they are no longer landed by commercial fishers and are voluntarily released.

Halswell Drainage District Revised Earthquake Reinstatement Plan

Environment Canterbury manages the Halswell Drainage District and, following significant damage in the earthquake of September 2010, produced a comprehensive Earthquake Reinstatement Plan.

This has now been updated and investigates changes to the Halswell River following the 2010 and 2011 earthquakes. The plan, which was outlined at a community meeting in March, covers progress, works required and costs to reinstate the waterway capacity and bank stability of the Halswell River and the associated drainage network.

The reports can be found on the ECan website.

WET Trust meeting

The next WET Trust meeting will be held on Monday April 30th, 6.30pm, Habgood Lounge, Lincoln Events Centre.  All welcome.

Recent Research from Lincoln University

In 2011 Katie Collins (MRS) and Aminath Nazra (MAppSc(Envt.Mgt)) each completed research on restoration work done by the Trust. Links, and an outline of findings provided by Hamish Rennie, Senior Lecturer in Environmental Management and Planning at Lincoln University (and WET Trustee), is below.

Katie’s thesis, submitted as part of her Masters of Resource Studies is a look at Evaluating the effectiveness of riparian plantings on water quality: A case study of lowland streams in the Lake Ellesmere catchment.  It can be downloaded from the Lincoln University Research Archive.

Nazra submitted a dissertation as part of a her Masters of Applied Science. Her topic was Understanding the Spread of Riparian Restoration in the Te Waihora/Lake Ellesmere catchment and it is also available from the Lincoln University Research Archive.

Evaluating the effectiveness of riparian plantings on water quality: A case study of lowland streams in the Lake Ellesmere catchment

Katie’s research included surveys of water quality indicators above and below selected restoration sites to see if there was any statistically significant change in water quality that might be attributable to the plantings.

Although the sites selected (on Harts Creek, Birdlings Brook, and Boggy Creek) are often used as good examples of riparian restoration in the Lake’s catchment, they fall well short of the minimum width of planting recommended by experts. They are also relatively short lengths of planting. Consequently, we had not really expected that the plantings would result in any statistically significant improvement in water quality until they were much more mature, if at all.

Some of the results were quite mixed and did not provide any clear evidence of significant changes. However, we were surprised to find significant increases in dissolved oxygen content and decreased turbidity at the downstream ends of the restored sites. Basically, this means better conditions for fish (and clearer water to enable us to catch them!). The results of this research have been accepted for publication in early 2012 in the well-respected, international scientific journal “Restoration Ecology”.

Understanding the Spread of Riparian Restoration in the Te Waihora/Lake Ellesmere catchment

Nazra’s research was seriously disrupted by the 22nd February earthquake. She was particularly interested in understanding how the concept of restoration was being spread in the catchment and applied theories of innovation and diffusion to her analysis.

These approaches are usually used to explain the adoption of new farm equipment or practices, and are not common in looking at restoration work. Because of the earthquake, the results are tentative, but it seems clear that the network of professionals working for community organisations (like WET) and councils play a critical role in the uptake of restoration. This is important as it supports the need to have continuity amongst people in such positions in these organisations and the need for councils to support NGO staffing and their own ‘care’ people if the community is to see real improvements on the ground.

From a Trust perspective it was good to get this independent validation of the efforts our staff have expended in building networks with council staff at several levels and, as a ratepayer, the value that councils get from supporting the Trust as well as its own staff. The message to staff is that time spent in networking is not wasted!

Lincoln University Research Archive

A search of the research archive at Lincoln University will produce many theses and dissertations with relevance to Te Waihora/Lake Ellesmere or related topics. Recent work by Katie Collins and Nazra Aminath are examples.

All students submitting work in recent years have been asked to give permission for their work to be included in the online archive and to be freely available. Where possible permission has been sought from former students to make earlier research available.

WET projects featured at National Wetlands Restoration Symposium

WET Restoration Consultant, Stephen Brailsford, was a presenter at the National Wetland Restoration Symposium in Invercargill in March 2012.  Stephen explained the practical lessons learned from WET’s Riparian Restoration Programme and the current Sustainable Drain Management project to a large and enthusiastic audience from around New Zealand. His presentation (which can be downloaded here) features many before and after photos and shows what can be achieved with good planning and efficient use of resources. Presentation notes help to explain the messages included in the presentation.

Sustainable Water Use – a public forum

Another event coming up on April 4th 2012  for anyone interested in water issues in urban and rural Canterbury.  Details can be downloaded here.

Kim Hill Hot Debate

This year’s Hot Debate, organised by Lincoln Envirotown as part of Earth Hour 2012, is on the topic of The Future of Food in Canterbury.

It’s on Thursday March 29th at 7.30pm at Lincoln and full details are on the Lincoln University website. Doors open at 7pm.

To find out more about what’s happening for Earth Hour 2012 in Selwyn, visit Lincoln Envirotown’s website.

Selwyn-Waihora Limit Setting

Environment Canterbury is hosting a series of focus group meetings to assist with making recommendations about the rules that will be included in the the Selwyn-Waihora chapter of the Land and Water Regional plans to limit the nutrient loads reaching the waterways.

Further information about the process and the scenarios that will be discussed is included in the first information sheet and background information and the the presentations from a range of experts are on the website.