### ODT Online Thu, 7 Jul 2016
Flood review clears DCC staff findings
Dunedin City Council staff have been vindicated by peer reviews which backed their findings over the cause of last June’s devastating floods. The reviews, carried out by infrastructure consultancy firm Opus, backed the council’s findings South Dunedin and other parts of the city would have been flooded even if the city’s stormwater system was running at full capacity.
Opus peer reviews of DCC flood reports received (same day) following a LGOIMA request made on 7 July 2016:
DCC Nov2015 rpt review-final (PDF, 395 KB)
DCC Apr2016 rpt review-final (PDF, 329 KB)
A truly independent inquiry into the council’s performance around last year’s South Dunedin floods remains long overdue, writes Dunedin engineer Neil Johnstone.
### ODT Online Thu, 14 Jul 2016
Opinion: Report skims surface of South Dunedin flood saga
By Neil Johnstone
OPINION Readers of the Dunedin City Council-funded independent peer review of its post-flood reporting (ODT, 7.7.16) should be wary. The council’s delight with the review may prove short-lived. In brief, the Opus review:
● Recognises the 1968 rainfall event was bigger than that of June 2015 (contrary to repeated council claims).
● Fails to explore the reasons why the 2015 flood was a disaster, and the 1968 event was not.
● Makes assumptions about groundwater levels without referencing the actual data.
● Appears to consider the council’s assumption of zero ground infiltration has merit (note: the data disproves this).
● Believes mud-tank blockage impacts of the flood were “localised” (too bad if you were a local), but fails to consider the likely widespread impacts on South Dunedin of blocked mud-tanks in the St Clair catchment.
● States council reviews “suggest” its failures at the Portobello Rd pumping station caused an increase in flood levels of about 200mm.
● In fact, the first council review leaves the reader with no more than an opportunity to infer this, while the second council review only states that the failures may have influenced “the length of time flooding was evident”.
● I do not recall the council actually publicly admitting the 200mm figure before the South Dunedin Action Group meeting of June 21.
● Fails to address the flood impacts of the council’s total failure to operate its Musselburgh pumps for stormwater relief.
● Makes general statements to the effect that “primary” flooding would have occurred under any circumstance. South Dunedin residents know that “overwhelming” of stormwater infrastructure was not the concern; the avoidable flooding of our people’s houses and businesses was.
For all of the above reasons, and more, the Opus finding the council report’s conclusions were “robust” is concerning. A truly independent inquiry into the council’s performance pre, during and post-flood, at staff and political levels, is long overdue. ODT Link
Related Posts and Comments:
● 7.7.16 Where is the unreserved DCC apology to … South Dunedin ?
● 4.7.16 Presentations available —a) 4 July USA —b) 20 June SDAG
● 28.6.16 The Star and RNZ on raised flood levels #SouthDunedin
● 27.6.16 CULL commingled #AGWbullsfeatherartists
● 21.6.16 Mayoral Statement to South Dunedin
● 20.6.16 Public Meeting: South Dunedin Action Group #tonight
18.6.16 South Dunedin stormwater pipes —getting past the desktop ICMP
● 17.6.16 So we’re going to play it this way #SouthDunedinFlood
● 16.6.16 Public Meeting: South Dunedin Action Group #AllWelcome
● 6.6.16 Listener June 11-17 2016 : Revisiting distress and mismanagement
6.5.16 South Dunedin Action Group: Notes of meeting with DCC (3 May 2016)
14.4.16 South Dunedin flood risk boosters #ClimateChangeCrap #PissOffPCE
26.2.16 Mudtanks and drains + Notice of Public Meeting #SouthDunedinFlood
● 31.12.15 2016, have mercy !@$#%^&*
10.4.15 DCC: Natural Hazards
*Bullet points indicate comments entered after the public meeting 20 June.
█ For more, enter the terms *flood*, *sea level rise*, *stormwater*, *hazard*, *johnstone*, *opus*, *hendry*, *south dunedin action group*, *debriefing notes* or *listener* in the search box at right.
Posted by Elizabeth Kerr
Election Year. This post is offered in the public interest.