MARINGI FOREST FIRE, 28 FEBRUARY 2006

 

Phill Wishnowsky, PRFO, Wairarapa RFD

 

[Presentation made at 2006 FRFANZ Conference]

 

WAIRARAPA RURAL FIRE DISTRICT

 

The WRFD covers approximately 600,000 hectares and extends from the top of the Tararua and Rimutaka Ranges to the east coast, and from Mount Bruce Wildlife Centre down to Cook Strait. The District consists of three primary district zones:

 

*  Tararua and Rimutaka Ranges: the Ranges are generally high rainfall indigenous forest DOC lands with some gorse and scrub areas along the fringes. Main areas of concern for fire management are the fringes, the railway corridor and the Rimutaka Hill Road.

 

*  Ruamahanga Valley: the Valley is where the population is concentrated so this is where we have most of our fire incidents. The Valley is generally intensively farmed, with dairy, viticulture and horticultural land uses. While the incidence of rural fire is high, the probability of a large scale incident is low. Access throughout the valley is good and our resource levels are also good.

 

*  Eastern Hillcountry: this makes up more than half the total land area of the WRFD, and it is this area that presents us with our main issues. Access throughout this area is restricted, with many areas remote (more than one hours drive from the Ruamahunga Valley). Most of the roads through this region extend from the main valley out to or near the coast (east –‘west access) but access north and south is limited. It is not uncommon to travel two hours to move 10 km along the coast.

 

The large land mass, restricted access, numerous small rural communities and rapidly increasing coastal development and the concentration of many exotic forest and extensive scrublands all add to our problems. Exotic forest ownership is very fragmented. The four main forest companies in the Wairarapa account for about 60% of the total estate. Key funding agencies. Other 40%. Coastal development in the Wairarapa is currently booming, with many high value residential developments occurring in very remote locations. Many of these developers/owners have an expectation of urban style fire protection services ‑hard to achieve when you are an hour away.

 

The Wairarapa has been, and probably still is to a certain extent, an incident waiting to happen. The Maringi Forest Fire has certainly been a huge wake-up call, and the challenge now is to use this incident to reinforce the way forward. The Wairarapa has a long history of

 

*  Higher than average (for NZ) Fire Danger Ratings

*  Significantly few incidents of note

*  Apathy and a belief that we are doing things right... an attitude reinforced by the lack             of incidents.

 

In 1995, I presented a proposal to establish an enlarged Rural Fire District. A cornerstone of this was the understanding that we were seriously under-prepared to react to an incident of any scale. In 1997 the NRFA funded a cost benefit analysis which supported the proposal. Progress was stymied by the apathy and the belief that all was OK. The retirement of key personnel plus a slightly nervous reaction following the Wither Hills Fire of 2000 in MarIborough resulted in the RFD proposal gaining support, to the point where in mid-2004 we finally achieved buy-in from all the main stakeholders. On 1st December 2004, the Wairarapa Rural Fire District was gazetted. An interim PRFO was appointed, and the process of seeking a full time PRFO commenced. Over the next six months our efforts to find a suitable PRFO proved fruitless. The primary reason given for individual's reluctance was the uncertainty created by the DIA legislative review.

 

My appointment as PRFO in July last year was hopefully the catalyst for progress. I must admit I accepted the appointment with some trepidation and reservation given my appreciation of the situation. I suppose I am encouraged about where we are 12 months down the track, but I still worry about where we may finish up. Just last week, I received a response from one of our key stakeholders saying they will not commit to a programme of supporting upgrades for equipment until they know the outcome of the DIA legislative review. Another example of the damage this process is causing. In snooker, to be tucked in behind the eight ball may be an advantage but snooker is not necessarily life. No where near as important as golf or rugby.

 

I want to touch on three fire incidents. The biggest fire the Wairarapa has seen for many years ‑ if ever, I mean a forest fire. The Maringi Forest Fire, and a couple of others that have messages as well.

 

The Maringi Forest Fire started sometime about 1030 hrs on 28th February 2006. A 111 call was received at 1132 hrs stating a forest fire existed in Maringi Forest. This started the one test of the fledging Wararapa Rural Fire District that we did not want ‑ then, now or ever. The fire was caused by a chainsaw and started in conditions which were conductive to an active fire. Two RAWS sites indicated similar conditions to the fire environment at 1300 hrs:.

 

station

 

Temp

RH

Wind

FFMC

DMC

DC

ISI

BUI

FWI

Castlepoint

 

 East Taratahi

23km SE of the fire
40km SW of the fire

15 C

 

19 C

66%

 

47%

SW 57

 

SW 32

84

 

89

16

 

46

334

 

426

33

 

20

29

 

73

39

 

42

 

                                                                                                                                                            

The fire burned vigorously throughout the afternoon with a number of crown runs, but was 'contained' by the south‑westerly winds, to a corner of the forest where it continually burned out where it reached the forest boundary despite the presence of rough pasture and extensive scrub areas close by.

 

At 1802 hrs the south‑westerly winds died allowing a concentrated attack on the fire perimeter, containing the fire to 15 hectares. The next day mop up continued through the morning until extreme weather conditions in the afternoon caused multiple escapes. Weather conditions at 1300 on Wednesday 1st March were

 

station

 

Temp

RH

Wind

FFMC

DMC

DC

ISI

BUI

FWI

Castlepoint

 

 East Taratahi

23km SE of the fire
40km SW of the fire

19 C

 

24 C

50%

 

31%

NW72

 

W 30

87

 

91

18

 

49

339

 

432

104

 

24

32

 

76

82

 

49

 

Castle point recorded a maximum wind gust of 156. Cross over conditions occurred soon after the 1300hrs. The Maringi Forest Fire had two periods of extreme, out of control fire activity ‑ from the time ignition took hold to 1802 hrs on Tuesday and from the time of breakout until midnight on Wednesday,. The fire destroyed about 193 hectares of 11, 12 and 13 year old pines. Mostly pruned to 6m and thinned. Available fuel loadings were high ‑ mid summer, recently thinned, lots of cured grasses following a moist springs, ground fuels up to 2 metres deep.

 

During the two periods of fire spread, extreme fire behaviour was observed and measured. The fire had some "good" examples of extreme fire activity which we were able to quantify with the assistance of Grant Pearce. Details of each run were verified by more than one observer which increased confidence levels. We quantified 15 fire runs ‑ almost all were crown fires. The measured runs occurred over the two days of active fire. The rates of spread ranged from 684 m/hr to 2407 m/hr.

 

Two runs, of 2407 m/hr and 1604 m/hr:

 

*  Were downhill runs

*  Occurred when wind speeds of over 150kph were recorded at Castlepoint RAWS.

 

One crown run occurred into a 140kph wind down slope. This was later identified as caused by a localised wind dumping effect ‑ something to remember when deploying resources.

 

Between 0300 and 0500 on the third day, 16mm of rain fell on the fire, allowing full deployment of resources through the third day and night and into the fourth day by which time the incident was handed over to the forest owner.

 

The Maringi Forest Fire destroyed about 193 hectares, 4.5 km of boundary fence and less than 4 hectares of pasture. Fire suppression costs were between $100K ‑$200K. Not surprisingly we have issues with payment of the bill.

 

Two other fire incidents from last season warrant mention.

 

  1. The first was a fire in a gorse block that was started by lightning, on 23 December 2005. An "old" local had consistently burned the area every few years to keep the fire threat down. He died and over time, fuel loadings increased. Then we had a fire. On Christmas Eve fire crews and machinery were deployed to save a group of houses under threat. Once this area was secured we left the fire to burn out. Multiple 111 calls for the next 11 days at least showed us our publicity campaigns were working.
  2. A fire burned through about 2 hectares of 10 year old pruned and thinned pines ‑ cause: owners cutting gorse, heaped up and set alight. Wind got up, fire escapes. Owners excuse’: burning the gorse to reduce the fire risk.

 

We have come a long way in the last 12 months. Highlights are:

 

*  Our ability to mount a multi‑agency response, with 15 agencies responding to the Maringi Forest Fire.

*  Purchase of a new rural fire appliance for Ngawi.

*  Approval/support for a new VRFF at Glenburn/Flat Point.