Close mown? | Golf Monthly
For instance, our course has drainage lines criss-crossing the fairways which constantly sink - no matter how many times they are topped up. The grass in these depressions simply cannot be cut by the fairway mowers - and consequently is 1 to 1.5 inches longer than what we would regard as "fairway height" - even though they are most definitely on the fairway. Should we regard any grass on the course of this length as closely mown? Obviously not, else pretty much all the first cut would be regarded as "closely mown". Yes you should have pick & place relief from these as (mostly) one is definitely in the middle of the fairway. But no, you should not have relief when on any grass of this length on the course.
Hence my opinion that closely mown (in terms of fairway height) has to mean the modal (most common) value of fairway height, rather than mean (average) or median (middle) value of height.
Ps: we get round it by having a local rule defining these channels as GUR - which solves a multitude of issues. IMO, the OP's course should do the same (if only by a white line) for this uncut bit until such time as it is cut.