Early voting has begun, and the Alameda County Registrar of Voters office is open for residents who are ready to cast their ballots in person.

The office, at 1225 Fallon St., features a number of voting booths, and is open weekdays from 8:30 a.m. to 5 p.m. and this weekend from 9 a.m. to 3 p.m. The public entrance is on 12th Street.

“They can come into our office and vote early,” said Alameda County Registrar of Voters Tim Dupuis. “We have every ballot type in my office right now.”

Dupuis said mail-in ballots have already been pouring in. About 30% have already been received, including more than 175,000 vote-by-mail ballots and 3,000 ballots from military and permanent overseas voters. The total registration for the county is 888,780, with about 67% registered as vote-by-mail and permanent overseas.

Dupuis said Wednesday he thought more vote-by-mail ballots had already been submitted for Tuesday’s race than the total that were submitted for the state primary in June. His office can’t legally begin tallying ballots until Election Day, which comes Tuesday, Nov. 8. But he said the ballots are staged and ready to go.

Worth noting: Vote-by-mail ballots (previously known as “absentee ballots”) can be mailed Election Day but they will only be counted if they are postmarked by Nov. 8 and received by Friday, Nov. 11, Dupuis said. [Update: He clarified after publication, “Because of the holiday, we will receive and check postmarks until November 14. The postmark still will need to be on or before election day.”]

“That will actually be a significant number,” Dupuis said. “Historically, it’s been a lot of votes that get dropped off.”

Those who don’t trust the mail to get their ballot to the Registrar of Voters in time can drop them off at any Alameda County polling location, or in any ballot drop box. (Downtown Berkeley has one at 2180 Milvia St.)

There’s also a drive-through ballot drop-off station outside the René C. Davidson Courthouse — where the Registrar of Voters is located — at 12th and Oak streets in Oakland. Motorists who use the drive-through station can get an “I voted” sticker when they do the drop-off.

Subscribe to the Daily Briefing Don’t miss a story. Get Berkeleyside headlines delivered to your inbox. Don’t miss a story. Get Berkeleyside headlines delivered to your inbox.

Dupuis said the first round of returns will be the result of the early votes that were received before Monday morning, Nov. 7. That’s followed by the returns for votes cast in person Tuesday. The vote-by-mail ballots that are dropped off at the polls aren’t counted until later, because the registrar’s office needs to check them against the records to make sure only one ballot was cast per person.

Current Berkeley totals for registration and vote-by-mail are not readily available because that would require a level of manual sorting that would be too labor intensive at this point. At the time of the June 7 primary, Berkeley had 79,232 registered voters, and a turnout of about 58%. That was a higher turnout rate than the county, which had a 49% turnout for 833,803 registered voters.

Dupuis said he’s expecting to see a 70-75% turnout rate overall for the county for this election.

He said his office is encouraging people to come in to vote early to avoid the crowds.

“We know that it’s going to be a big turnout,” he said. “We’re getting ready.”

But for those determined to vote Tuesday, as long as they are at the polls by 8 p.m., they should be able to vote.

The early voting option isn’t a new one, Dupuis said, but it’s one that many members of the public don’t seem to know about. Dupuis said a lot of people made use of it last weekend, however, and he expects to see the same this weekend.

“There were times when every one of those voting booths was filled with a voter,” he said. “It’s neat to see that many people coming out on a weekend to vote.”

People who do not receive a ballot or have a problem filling out their mail-in ballot can simply go to any Alameda County polling location Tuesday to vote provisionally. And, if you vote in person but find yourself in a jam and can’t make it to your assigned polling station, you can fill out a provisional ballot at any polling location in the county.

“If a voter is qualified to vote and votes provisionally, his or her ballot will be counted,” according to the Registrar of Voters website.

One reader asked Berkeleyside what to do if you err in filling out your ballot. Dupuis said people do at times use white-out or other techniques to correct a mistake. He said as long the intent of the voter is clear, the vote should count. But he said, “to be clean,” residents can go to a polling location to vote provisionally if they are concerned.

Once the ballot is submitted, however, there’s no way to get it back or change a selection.

Dupuis said, even with such a high vote-by-mail percentage, Alameda County is so diverse that “every vote counts.”

He pointed out that, particularly with the local races, winners can be determined by a small margin. (In 2012, in Berkeley, Lori Droste won her district by 16 votes, though she was also the top vote-getter in every round of ranked-choice voting.)

“You have to wait until all the last votes come in,” Dupuis said. “You can’t say the race is called on Election Night, even when all the precincts are in.”

Fun facts from the June 7 primary returns

Berkeley (57.97%) had the third-highest turnout in the county, following Albany (66.99%) and Piedmont (65.99%).

Bernie Sanders won in Berkeley, with 22,993 votes compared to Hillary Clinton’s 19,120.

Sanders also won in Albany, Emeryville and Oakland.

Donald Trump got the most Republican primary votes in Berkeley (454), followed by John Kasich (306) and Ted Cruz (98).

The Green Party’s Jill Stein got 278 votes.

Read more about provisional voting on the Registrar of Voters website. Read more about how vote-by-mail ballots work.

See complete election coverage on Berkeleyside. More stories are being added daily. See the 2016 Election Hub.