Re: Rules Question

The course may not change the Definitions, but it is clear they are allowed to have local rules.

Everyone is familiar with particular courses, which have areas, not necessarily with water, considered as hazards. There are red or yellow hazard stakes bordering quarries, sunken areas, heavily brushed or wooded areas, and such. So, they are considered as lateral hazards, for the sake of scoring.

Another local rule, which is becoming more prevalent in North America, are the enviromentally sensitive zones, which are marked with white stakes tipped with green. With these, you are not allowed to enter, but you drop your ball where it entered, in some cases with no loss of stroke. Ironically, these are generally quite a ways off the fairway, where a ball would normally be in the woods or tall fescue, or out of bounds, however, you are given a free drop. It's like getting a free drop, when you hit it into the tall rough and heather at Carnoustie.

Re: Rules Question

Whilst they may make Local Rules they must conform to the strict conditions set down by the USGA/R&A in the Appendix.

As provided in Rule 33-8a, the Committee may make and publish Local Rules for local abnormal conditions if they are consistent with the policy established in this Appendix. In addition, detailed information regarding acceptable and prohibited Local Rules is provided in "Decisions on the Rules of Golf" under Rule 33-8 and in "How to Conduct a Competition."
If local abnormal conditions interfere with the proper playing of the game and the Committee considers it necessary to modify a Rule of Golf, authorization from the USGA/R&A must be obtained.

Decision 33-8/35 specifically prohibits the practice.

33-8/35 Local Rule Treating Rough as a Lateral Water Hazard
Q. The areas immediately adjacent to the fairways consist of large embedded boulders, thick desert brush and pri*kly cactus. A player whose ball comes to rest in such areas has no opportunity to play a stroke. Would it be proper to make a Local Rule under which such areas would be treated as lateral water hazards?
A. No. There are many courses where the areas adjacent to the fairways are of such a nature that a ball therein is almost always lost or unplayable. Thus, such a situation is not abnormal.

Environmentally Sensitive Areas (ESAs) are in fact covered by an approved Local Rule (see App I Part A Clause 3)

3. Areas of the Course Requiring Preservation; Environmentally-Sensitive Areas

Assisting preservation of the course by defining areas, including turf nurseries, young plantations and other parts of the course under cultivation, as ground under repair from which play is prohibited.
When the Committee is required to prohibit play from environmentally-sensitive areas that are on or adjoin the course, it should make a Local Rule clarifying the relief procedure.