Local Govt | National News Video | Parliament Headlines | Politics Headlines | Search

 


Mayoral Taskforce On Flooding – Report To Council Meeting

Mayoral Taskforce On Flooding – Report To Council Meeting Of 12 May 2014

[Full document: MayoralTaskforceOnFloodingReportToCouncilMeetingOf12May2014.pdf]


2. EXECUTIVE SUMMARY

2.1 The large number of recent floods in Christchurch is due to a run of major storms. It is clear that the severity of the floods has been aggravated by earthquake damage to the land and stormwater network, particularly due to land lowering in some places such as Flockton Basin.

2.2 The Taskforce focused on the most vulnerable of those households affected by regular flooding since the earthquakes. Vulnerability has been assessed using both physical and social factors. It was determined that the most vulnerable were those with two or more instances of flooding above the floor level. The next most vulnerable were those houses with two or more instances of flooding beneath the house but not up to the floor.

Restricted access to dwellings defined the third category of vulnerability.

2.3 The Taskforce examined a range of short-term flood defence measures to reduce impacts of regular flooding. These included house defence and local area schemes which benefit more than one dwelling. Where neither of these options was practicable then short-term relocation of the household was considered an option.

2.4 House defence typically involves raising the house (permanently), tanking the house (waterproofing just above the level of frequent flooding), bunding (either raised mounds or sandbags) or property re-grading to improve drainage of floodwaters away from the house. Local area schemes are more complex, but typically involve diversions, bunding and pumping, and would typically be located on the street or within drainage easements.

2.5 Local area schemes provide wider benefits in terms of addressing the issues experienced by the most vulnerable houses, as well as those considered less vulnerable in the surrounding areas. This helps preserve occupancy within affected areas, which is an important component of strengthening these communities and improving the quality of life.

2.6 The field teams had limited time to carry out all of the above work and so a large amount of judgement and interpolation was necessary. It is considered that the process was sufficiently robust to provide a high level of confidence in the outcomes. However there may be further vulnerable properties within the city which have not yet been identified.

2.7 The information gained by the field teams allowed an assessment of which houses were most vulnerable, and a comparison of the costs of individual house defence and a local area scheme. In most instances it was found that the local area schemes were not only more cost effective, but also provided benefit to a much wider area.

2.8 In summary, based on recent storm event data and community feedback, there are approximately 994 households assessed as vulnerable to regular flooding in Christchurch. Of those 56 are considered the most vulnerable due to impacts of flood water entering the house. The second most vulnerable are those households that have experienced frequent flooding under their houses. There are 451 households in that category.

2.9 The Flockton area has 30 of the most vulnerable households.

2.10 Any proposed long term flood defence schemes will not necessarily prevent such flooding in more extreme events, beyond the one in 50 year flood, as experienced on 5 and 6 March 2014.


© Scoop Media

 
 
 
 
 
Parliament Headlines | Politics Headlines | Regional Headlines

Gordon Campbell:
On War Crimes And The Afghan Insurgency

Truly, with friends like former defence Minster Wayne Mapp, the SAS does not need enemies. At the very least, the Hit and Run book has raised the possibility that the New Zealand SAS committed war crimes in the attack they led in Afghnistan upon the villages of Naik and Khak Khuday Dad...

Mapp’s attempted defence of the SAS on RNZ this morning unintentionally indicated that collective punishment was baked into the planning exercise for the raid, and also into how the raid proceeded on the ground. More>>

 
 

Little Heading For Court: Apology Over Donation/Hotel Contract Claims Not Accepted

Today I want to publicly apologise unreservedly to Mr Hagaman for any hurt, embarrassment or adverse reflection on his reputation which may have resulted from my various media statements. I have offered that apology to the Hagamans. More>>

ALSO:

Biscuit Tin Of Democracy: World Heritage Site Protection, Ombudsman and Equal Pay Bills Drawn

On Thursday, 23 March 2017 three places are available on the Order Paper for the first reading of a Member’s bill. The ballot was held, and resulted in the following bills being drawn... More>>

ALSO:

Emissions Plan: NZ Needs More Science, More Trees, Fewer Beasts

A combination of technology breakthroughs, much more plantation forestry, and a big switch away from pastoral, particularly dairy farming, are identified as the key elements of any approach New Zealand takes to reducing its carbon emissions to a net zero level, according to a new report sponsored by the New Zealand chapter of GLOBE, a multi-party, global parliamentary grouping. More>>

ALSO:

"Backed To Win Seats": Labour Māori Seat MPs Won't Stand On List

The Labour Party is backing a request from its Māori seat MPs to stand as electorate MPs only, says Labour Leader Andrew Little. More>>

OutsKey: John Key's Valedictory Speech

I rise to address this House for the very last time. It has been a huge privilege to have served the people of Helensville as their member of Parliament, and, of course, the people of New Zealand as their Prime Minister. More>>

ALSO:

Productivity Commission: New Models Of Tertiary Education Are Coming

The report is a broad-ranging inquiry into how well New Zealand’s tertiary education system is set up to respond to emerging trends in technology and the internationalisation of education, and changes in the structure of the population, and the skills needed in the economy and society... More>>

ALSO:

PM's Press Conference: Water Everywhere

Monday's Post-Cabinet press conference focused on water, with the Prime Minister fielding questions about the possibility pricing water taken for export. Mr English said the government was directing their water allocation technical advisory group to include export water in considerations. More>>

ALSO:

Get More From Scoop

 

LATEST HEADLINES

 
 
 
 
 
 
 
 
Regional
Search Scoop  
 
 
Powered by Vodafone
NZ independent news