When there are not enough active members attending church, wards may combine as others are done away with. When there is growth in the church, new wards and stakes are created. I have lived in such areas that affected ward boundaries.
I am too young to remember when my mom and neighbors were a part of the third ward. I had always known us as the forth. Just after or right before I had graduated high school, it was announced that our ward boundaries would be changing as our stake would include members on the west side of state street. One and a half streets were made a part of the seventh ward. I remember there wasn't much support in the "sustaining vote" - nevertheless, it was carried out.
It wasn't too many years later when I was out on my mission, mom wrote to tell me that another stake would be created and we would have our one and a half streets of members back in our ward. I remember, sometime after returning home from my mission, a brother giving a talk in sacrament meeting about a short-lived calling that he had accepted in the 7th ward. He had been called as a counselor in the bishopric and served for one week before it was dissolved. I remember him saying he had never been part of a ward that had been dissolved, let alone had accepted and served such a short calling.
Even though the 7th ward had been "dissolved" - it was due to the growth of a new stake. It seemed to be an opposite problem when I lived in Kearns.
We had a bishop who had compared our ward boundaries to a giant apartment building in which move-ins and moving out happened so constantly that it was sometimes difficult to keep track - especially as the church would continue mailing back church records as it was always the "last known address" We would even get records of members with addresses that were not even a part of the ward boundaries.
The stake lost two wards during the time that we lived there. I remember one member complaining that she had lived in eight different wards during her marriage and lived at the same address through all eight changes. Thus when the stake announced that the boundaries would change again, I was prepared to live in another ward. The change put my next-door neighbor in a different ward than I; she was not happy about the change after having lived in the same ward for over 30 years.
Before we moved to Douglas County, Canyonville and Myrtle Creek had been two separate wards. I don't know when the boundaries changed, but the wards were combined and the church building in Canyonville was sold. It takes 45 min to an hour for some of our ward members to get to the building in Myrtle Creek.
When we moved to Douglas County there were six wards: Winston, South Umpqua, Sutherlin, Roseburg, Melrose and Newton Creek. The last three all Roseburg wards but none go by those names anymore, but rather names of the dividing streets: Garden Valley, Harvard, North Umpqua, and Parkway. Growth: our stake now has seven wards. South Umpqua, North Umpqua, and Sutherlin are the largest wards geographically. Each ward is geographically larger than the other four wards put together. May we continue to grow.