Managing a muddy good event
By Christo Peters - Fri 31 Mar 2023 8:47pm

Early in January Paul Ireland and I had a call from Rob Garden asking us to set an event in Riverhead in February. We asked to use the Robinson Rd map and we decided on the south end of the map as that was due for felling next year and the northern end had been used last year. Robinson Rd is great for setting challenging red courses but we had a problem as there were no suitable tracks for white and yellow courses. We were going to have to build a track across the valley and this would require a bridge as the stream was a bit too deep for youngsters and beginners. We got together a small group of volunteers in mid January and in one morning we built the track and a bridge.

On Friday the 27th of January disaster struck, a major rain event crossed over parts of the Auckland region including Riverhead. On the Sunday Paul and I went in to check control sites we found over three metres of water had swept down the valley washing away fully grown pine trees and other vegetation. The crossing point was a mess and the bridge had disappeared. The area was covered in a thick layer of silt. We also discovered numerous new slips and trees down around the map and as result we had to change a number of the planned control locations to safer positions.
We held off rebuilding the bridge due to a forecast cyclone. Between the 12th and 14th February Cyclone Gabielle passed over the region. We were surprised to find very little further damage apart from a few more trees down, only one control site was impacted.

We organised another working be on 18th of February and with a load of wood kindly donated by Cyclone Gabriel we rebuilt the bridge and finalised our course.
On Friday the 24th Paul and I headed out to the forest to put out the controls. The forecast advised that there would be heavy rain and thunderstorms for late afternoon.  Approx 3pm as forecast the heavens open and it really poured down along with thunder and lighting. About 3.30pm we called it a day. It was just too wet – it was absolutely pouring down. It turned out that we left the forest just in time. Localised flash flooding occurred in the area again – more slips and road closures. The road out of the forest was flooded again. This weather bomb, was again, worthy of national news.
The next day Paul and I headed out to the forest with trepidation. The road was open although there was one tree hanging over the road near the event centre. We went down to where the bridge had been. It was gone and there was a large pond. Again three meters of water had gone down the valley with such force it had moved more pine trees. We soon discovered our bridge downstream now acting as a dam. We couldn’t move it so we dug a channel around one side to clear the water and went off to place the remaining controls.
All control locations were okay although the forest was very wet and slippery. Reentrants were now small waterways and there were new mini ponds (tarns) in places – very Norwegian-like.

After placing out the controls we returned to the bridge. We dug a hole under it and that was like pulling the plug out of the bath. the water level dropped at least half a metre. We found our bridge footings still in place and we were able to move/ float the bridge back up stream and into place.

Some additional slips plus a couple of tree stumps needed to be added to the map. As the maps had been printed Paul drew on the changes to the maps on Saturday night.
The next day was the event. A couple of guys went down to the bridge with tools to secure the bridge and to place mats on the bridge approaches.
The controls put out on Friday were checked and fortunately they were all still there.
The event successfully proceeded against all the odds.
2 x Auckland anniversary, one in two hundred year tropical moisture rain events, one Cyclone Gabriel and an unusual thunderstorm with more rain than the cyclone… the show went on! 
Andrew de L’Isle 
Andrew de L’Isle and Paul Ireland and their intrepid planning ,was for an event for the North West Orienteering Club

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