Tucson's primary election will be held Tuesday, despite there being no contested races.

Why hold the election, then? Because it is required by law.

Ballots were sent to voters in Wards 3, 4 and 5 on Aug. 8. City officials, via press release, reminded voters that all ballots must be in possession of the city clerk by 7 p.m. on Tuesday.

The deadline to mail them back was Thursday. Voters who did not get their ballots in the mail and want them counted should drop them off at any of the four voting locations.

In Ward 3, Republican Ben Buehler-Garcia is the presumed primary winner, and will challenge Democratic Councilmember Karin Uhlich, the presumed winner in her primary.

Republican political newcomer Mike Polak II is the presumed winner in Ward 5, and Democratic Councilmember Richard Fimbres is the presumed winner in his race. They will face off in November.

Ward 6's Democratic Councilmember Steve Kozachik is also up for a second term and running unopposed in both the primary and the general election.

The general election will be Nov. 5, and all registered city voters are eligible to cast ballots. The election will be held entirely by mail.

Voters will also decide on two and possibly three initiatives: adoption of Plan Tucson, the city's general plan for 2013 and the next 10 years; and a proposed permanent increase in the city's base spending limit.

A third initiative, which proposes a change to the retirement system for city employees, is pending a court decision on a challenge to the way petition signatures were collected. The judge has until Sept. 16 to decide.