For the purpose of the regulations, the following districts are designated:

The boundaries of the districts designated in Section 17.08.010 are established as shown on a map entitled "Zoning Map," which accompanies and is made a part of this title. The district boundary lines on the map are intended to follow lot lines, the centerlines of roads, the centerline of roads projected, railroad rights-of-way, or the corporate limit lines, all as they existed at the time of enactment of the regulations. But where a district boundary line does not clearly coincide with lot lines, it shall be determined by scaling.

Where a district boundary line divides a lot which was in single ownership and of record at the time of enactment of the regulations, the use authorized on and the other district requirements applying to the less restricted portion of such lot shall be considered as extending to the entire lot, provided that where the more restricted portion of such lot is more than fifty feet beyond said dividing district boundary line, such less restricted use shall be limited to the portion of the lot lying within fifty feet of said boundary line.

Questions concerning the exact location of the district boundary lines shall be determined by the board of appeals according to the rules and regulations which it may adopt.

All territory which may be annexed to the village after the effective date of the ordinance codified in this chapter shall be placed in the A-l agricultural district until zoned otherwise by the village council.