Completion of the 2011 Wildfire Threat Assessment


On June 30, the TNRD reported completion of the field work on the Wildfire Threat Assessment of a parcel of Crown land immediately adjacent to Glen Grove Estates on Agate Bay Road.  The report was prepared by Bruce Morrow, R.P. F. of Bruce Morrow Forest Consulting Ltd. of Kamloops.  The site assessed is between the road, 100 meters west of the Glen Grove Road turnoff, and the Louis Creek draw.  The 2003 McLure/Barriere wildfire impacted the western edge of this site and directly threatened the adjacent homes.

This site was selectively harvested approximately 10 years ago, with a majority of the overstorey removed, leaving a very dense immature Douglas-fir layer. Trembling aspen has filled in some of the site post-harvesting.  The mature lodgepole pine left after harvesting has been decimated by the mountain pine beetle.  All pines over 15 cm in diameter are dead, representing approximately 20 per cent of the standing timber.  Two old landing piles are still on site, unburned.

The harvesting access trail is still open for four wheel drive access.  It traverses the accessed area, then follows the Louis Creek gully to the west, ending at an old gravel pit.  A side gully is located immediately south of the harvesting trail.  The road surface is stable but narrow, without any turnarounds.  The slopes adjacent to the Agate Bay Road are less than 10 per cent, while the slopes in the Louis Creek gully reach 75 per cent.  The Louis Creek gully is highly unstable; multiple sites of mass wasting are identifiable along the upper edges of the gully.

The report states that the assessed areas are an extreme wildfire threat.  The combination of a dense immature Douglas-fir stand, the dead standing lodgepole pine, the very low crown base height, the south aspect, and the very steep slopes in the Louis Creek gully all lead to the extreme wildfire treat.

While the homes adjacent to this area have a reasonable buffer of managed lawn between the forested land and the structures, in a fire, the candling/crown fire that could be expected would easily generate an intense ember shower that could ignite the structures.

The Glen Grove Road area was also reviewed for this assessment.  The area is dominated by Douglas-fir, trembling aspen and paper birch.  Land clearing activities have left a mosaic of deciduous dominated areas mixed with an older coniferous forest.  The community is only partly developed; over 80 per cent of the area is forested and the structures are scattered throughout.  The driveways are mostly narrow and of poor quality, with most being unsuitable for emergency vehicle access.  The only adjacent Crown land is east of the community, on very steep forested slopes.  A fuelbreak on the lower hillside, without extensive fuel modification on the private land, would have minimal impact on the wildfire threat issues in the Glen Grove Road area.

To significantly reduce the wildfire threat to the structures west of Agate Bay Road, the report recommends that the dead standing pine be removed; re-piling and burning of the old landing piles be done; the immature Douglas-fir be spaced and the larger ones pruned; and all felled and cut debris below 15 cm in diameter be removed.

In the Louis Creek gully, a lighter treatment is recommended, namely the falling of all danger trees between the access trail and private land; pruning of the larger live Douglas-fir; and removal of the felled and pruned debris less than 15 cm in diameter.

The Crown land assessed for the report poses a serious wildfire threat to the adjacent structures.  Carrying out the recommended tasks would significantly reduce this threat.  Minimal activity is recommended for the Louis Creek gully as it is very unstable.

Ron Storie, emergency services supervisor from the TNRD explained that they plan to discuss the report at their July board meeting.  “No action will take place until all parties concerned (including the area fire departments and communities) have had a chance add their input.  Once the TNRD board has given it their approval, it will go to the Wildfire Management Branch for approval.  This may take a month or two.”