Monthly Archives: May 2016

Land Drainage Recovery Programme

On May 24th, the Spreydon Heathcote Community Board hosted an information session on the Land Drainage Recovery Programme (LDRP) for our area.  Keith Davison and Peter Christensen presented to the group.  A very informative, well attended session gave specific insight into the challenges and scope of river damage following the earthquakes.  It was soon obvious that solutions will take time and funding to resolve, and will be very expensive.  The LDRP is setting in place short / medium and long-term strategies in its plans.

The goal of LDRP is to return flood risk to pre-earthquake levels, trying to find ways and solutions to prevent flooding.   Historically the Heathcote River has always flooded.  Several floodplain management strategies have been instigated over the years: Woolston Cut & Upper Heathcote flood plain ponding. Following the earthquakes there was a change in flood risk – areas.  Some had uplifted or subsided changing the way the water flowed across the Christchurch area.

What is the LDRP doing?

Assessment:

  • Re-assessing the whole city and starting again. The river flows are not behaving as they used to because of changed ground and water levels.
  • The LDRP is using detailed measurements to identify earthquake damage – the technical input data represents the ground topography and gives a new profile of the land
  • Understanding the new way the land drains is challenging
  • 100 different investigations were begun to determine options and solutions
  • The effects of climate change and sea level rising need to be taken into account
  • Expert opinions were sought from scientists in NZ and overseas esp The Netherlands

 

Investigations:

  • Developing concept designs for repairs to banks and structures. Assessment of the banks from the confluence with the Cashmere Stream to Ensors Rd is currently underway.
  • Upgrading the topography technical data of the Heathcote
  • Conducting flood level surveys adjacent to the Heathcote river to determine properties at-risk to flooding
  • Investigate options for flood mitigation in mid-lower Heathcote. This will be complex and difficult. LDRP will need to sort through the range of issues and solutions to get the best possible result.
  • Develop further storage in the Upper Heathcote basin – Sparks Rd. Two new basins have been constructed. Further land in the area has been bought to increase water storage and reduce the risk of down-stream flooding.

Upcoming maintenance work

  • All schedules are being reviewed to maximise spawning along the river: trout, whitebait.
  • Scheduled bank cut, including vegetation within the channel after June 1st 2016
  • Seek authorisation to remove minor slumps prior to October (have been on hold due to spawning restrictions)
  • Review weed harvesting schedule to optimise use of equipment.

What can we do?

  • Ensure that rubbish is not dropped into drains
  • Report any maintenance issues to the Council
    • Call 941-8999
    • Snap send solve app
    • If you are concerned about rising water levels, phone 941-8999 and ask for the Civil Defence Duty Officer to report your concerns

Conclusions

  • The issues are complex
  • Short-term solutions underway: Upper Heathcote storage, bank works & maintenance
  • Longer-term floodplain management options being developed

 

Waste Water system

  • Water has been getting in to the sewer system in heavy rain times. To help prevent this happening, the valves to keep the flows separate have been changed to non-return rubber valves, which will be much more reliable.
  • Vented manhole covers have also been inserted to prevent the manhole covers popping open when large amounts of water are flowing. More work is on-going to stop storm water getting in to waste water during heavy rain events
  • 50% of stormwater enters sewers from private properties (our houses)
  • There will continue to be adaption to the changes as the river finds its new equilibrium

Thanks to the Community board for arranging this very informative session.  It is easy to underestimate the difficulties post-earthquake that changes to the ground and river areas create.  The LCRA will keep you posted on other information sessions as they are held.

Advertisements

Rose Street matters

For the past several years Rose St, down the Barrington St end,  has created issues for residents and motorists.  Parking is especially a problem.  Winter conditions mean the grass berms become mud puddles.  In summer the corrugated berms make parking difficult.  Many of the berms have been privately ‘fenced off’ in an attempt to restore the grass, leading to a lack of access to parking spaces off the carriage way.  Recent attempts by the Council to remediate the berms have not been successful. There is increasing frustration with the way the street looks and how difficult it is to navigate.

Access onto Rose St by residents of side streets is also problematic.  Cars parked too close to corners or on the carriageway itself lead to reduced visibility and raise the risk of accidents.    The whole area has become busier, with increased traffic through the area from new subdivisions and driving traffic patterns. Much of this extra traffic overflows onto Rose St, making it even busier at certain times of the day.

Last August the LCRA sent a submission to the Community Board asking for the following:

  • yellow lines to be painted around the corners of streets leading on to Rose St
  • A reduced speed zone along the Barrington St end of Rose St to enable safer traffic flow
  • the yellow lines at the Rose St / Hoon Hay corner be extended further around the corner to aid traffic visibility
  • Rose St be considered in conjunction with any review of traffic management in the area.  This relates to the increasing congestion of Cashmere Rd especially once the Worsley’s Rd subdivision and Adventure park are underway.

At the May meeting of the LCRA committee, we decided to approach the Community Board directly to receive information about the submission and to push for some speedy action on the yellow lines especially.

Three of us attended the meeting on May 20th.  We were very well received and a constructive dialogue ensued.  We were direct about our frustrations and were thanked for presenting them to the Board.  The yellow lines request had been signed off at the last meeting and would be implemented as soon as possible. Our medium to long-term suggestions will be considered as part of the whole area development.  Our difficulties with the state of Rose St were signalled as a priority for some resolution.

We will keep you posted on progress.

 

Opawaho Heathcote River clean-up

may7river2             may7river1

May 7th was the clean-up of the Opwaho/Heathcote river.  The LCRA was responsible for the area from the beginning of Ashgrove Tce through to the Barrington St bridge, both sides of the river.  We were delighted to have 43 people turn up to help.  Some were Beckenham Cubs with their Dad’s who couldn’t do their morning session.  We had people come from Halswell, from up the hill and other areas as well as a good turnout from our own area.  Two groups were sent off to collect with their gloves, boots and rubbish bags.  The gorgeous weather made the clean-up a pleasurable exercise. The site supervisor noted that high-vis vests were ‘de rigeur’ in Christchurch nowadays so she wore her ‘Minnie Mouse’ ears to aid identfication.  It was also very heartening to have people cycle up, looking to help and keen to be involved. Great work Christchurch!

river cleanup1

Our area collected 22 bags with rubbish from a third to nearly full.  We found concrete blocks and pipes, advertising boards, a wire gate and pieces of wood.  The rubbish bags conained bottles, cans, plastic and rubbish bags.  Our river is cleaner following the efforts of a large number of people who helped to make it a great success and become an annual event.

river rubbish1             river rubbish2

 

We would like to that all our volunteers who arrived to help.  Thank you too to Cassells and the Cracroft Residents’ Association for the post-clean-up BBQ.  Thanks too to the Opawaho/Heathcote river Network for their organisation and support.