After considering the various options the match committee have decided to move the out of bounds fence in slightly so that the new drain is OUT OF BOUNDS. This will be marked by white posts and a white string line, matching most other out of bounds fences on the course. There is also out of bounds signage at this area. A diagram of the new markings is provided below.
The match committee made this decision based on trying to ensure the simplest and clearest solution is found. If the area is left as a drain relief would often need to be taken between the old out of bounds fence and the new drain by a right handed golfer, making this very awkward for the player. Whilst marking this area as out of bounds will slightly narrow the hole the match committee believes that the area lost is both (a) minor and (b) sufficiently off the playing line to have minimal impact on anything but a poor tee shot.
However as this area is now marked as out of bounds players are asked that should their ball be heading into this area they should hit a provisional ball off the tee if they are all unsure if their ball is in bounds or not.