In communicating to city hall, you want to do it in a way that provides a permanent record of your concern, a way that documents the receipt of your concern, and a way that results in some "official" action.
This requires a letter addressed "To The Mayor and Council," c/o Oshawa City Clerk.
When you write to your local councillor, there is no official record of your letter. A councillor could simply look at your letter and then throw it in the garbage. He may or may not give you a call acknowledging your letter but there is no "official" evidence of you ever having communicated in the first place. In any case, the individual councillor, has no "official" authority outside of his vote on council.
So the basic principle is, "An individual councillor has no authority on his own. The authority rests with council and a majority vote there."
Politicians, may at times, have some moral suasion in talking to bureaucrats and in knowing the ropes of city hall, knows who to talk to.
Since political authority is vested in council, the most effective way to get "official" consideration of your letter is to address it to the Mayor and Council, c/o the city clerk...in the case of emails to email@example.com.
Such letters to the mayor and council appear on the council agenda and council moves to receive the letter. The letter is public and can be viewed by those checking city agendas. An example of some of my letters to the Mayor and Council can be seen on pg 4 of the March 19 Council Agenda.
When a letter is sent to the mayor and council, it is "official" and "official" action follows. At times that official action is only to "receive and file" but by so doing a permanent record of your concern exists in perpetuity in the council minute archives. At times, your letter may result in a motion of council in which council takes specific action which is firm and official direction for action by city staff.
No such "direction" to staff is ever possible from a letter to your local councillor unless (s)he takes the issue to council by presenting a motion which is subsequently passed by council. The councillor may do this if he feels strongly about the issue but is not compelled to do so.
Any letters sent regarding your demands that the ward system be retained by city hall should be sent to the mayor and council so that your concern and your demands are officially received and archived in the council minutes.
Hopefully you will take the time to send an email to the mayor and council demanding that they retain ward voting for Oshawa.
If enough letters are received so that the politicians know voters are concerned and serious about this issue, council members would likely be motivated to rescind their moves to the general vote.
If the people are silent, council will rush headlong into the self-serving general vote...and all of Oshawa will suffer.
Get active Oshawa! Let us hear your voice!