More adventures in mapland - Tracing Plateau Stream
April 12th 2015, the second May 23rd 2015
I have crossed the Plateau in the lower Otaki many times; sometimes just passing through on the Waitewaewae Track sometimes on day trips in the area - including an unsuccessful attempt to get to the Otaki waterfall (reportedly located near where Kahiwiroa Stream joins the river), and various explorations of the high ridge lying between the Otaki River and Plateau Stream. But only this year did I notice a curious gap in the mapping of Plateau Stream on BP33; one could even be excused for concluding from the topographic map that a large chunk of the plateau is drained by Saddle Creek!
Presumably cartographers leave a gap when they are unable to determine a stream's course from aerial photos. But determining the course is not at all a problem on the ground with GPS. Indeed less so on the flat than in a narrow valley!
So one Saturday this April, Dave, Tim and I ascended the new Waitewaewae sidle track, quitting it on the ridge to strike east to Plateau Stream and south (downstream) a short distance to the major side stream entering on the true left. Then I jumped into Plateau Stream, GPS churning away, and apart from one deeper-than-crotch pool stayed in it till we reached a major forks just east of the saddle. This seemed to call for a second GPS so we turned around and sauntered back to the road end.
About a month later I returned, this time a party of five with four GPS bearers, David, Sue, Paul and myself with Sieny to keep an auditor-like eye on proceedings. This time we went up the old track to the saddle and then to the forks where we split into two groups: David and Paul to trace the true left or east branch, myself Sue and Sieny the true right or west branch. The plan was for each party to walk for 30 minutes up their branch.
The second map fragment shows the results obtained on these two excursions: it must be acknowledged this represents a minor correction to the topographic map in an area where it would in any case be difficult to come to navigational grief. It also indicates yet again (see the piece about Saddle Creek tributaries in the April 2014 Tramper) how difficult it must be, once a stream leaves a steep valley and starts to traverse a relatively flat but bush covered area, to infer the streamís course from an aerial photograph .
- Party members
- First party:Colin Cook (leader and scribe), Dave Reynolds, Tim Stone. Second party: Sue Boyde, Paul Bruce, Colin Cook (leader and scribe), David McNabb, Sieny Pollard