D.C. Council member Brianne K. Nadeau (D-Ward 1), right, has spent heavily on her contested re-election campaign over the past three months. (Matt McClain/The Washington Post)

With a week remaining before the D.C. primary, candidates are pouring their campaign cash into advertising and campaign materials aimed at getting voters’ attention in what many predict will be a low-turnout election.

The spending, outlined in campaign finance reports filed Monday night that cover the past three months, follows a tried-and-true playbook for local races, which District voters often don’t scrutinize until the last weeks of a campaign.

That is particularly true when no marquee race tops the ballot — as is the case this year, with Mayor Muriel E. Bowser (D) facing no strong opponents. In the heavily Democratic District, Democratic primary winners typically go on to victory in the general election.

The final sprint of campaign spending before Tuesday’s vote is most pronounced among incumbent candidates, most of whom enjoy a fundraising advantage over their challengers.

D.C. Council Chairman Phil Mendelson (D) spent $277,000 over the past three months, much of it on advertising, and raised $340,000. His opponent, left-wing activist and former D.C. Fiscal Policy Institute executive director Ed Lazere, spent $153,000 over the same period and raised $108,000.

Council member Brianne K. Nadeau (D-Ward 1) spent $154,000, more than triple the combined amounts spent by her three challengers — law librarian and Advisory Neighborhood Commissioner Kent Boese, former D.C. Superior Court magistrate judge Lori Parker and architectural drafter Sheika Reid.

Some political observers in Ward 1 have said that while Nadeau, a freshman lawmaker, is contending with some anti-incumbent sentiment, she is benefiting from the effect of multiple challengers who could divide the vote against her.

Not all incumbents have a marked financial advantage. The campaign committee of council member Anita Bonds (D-At large) has spent $41,000 over the past three months, compared with $37,000 spent by challenger Jeremiah Lowery and $31,000 spent by challenger Marcus Goodwin.

Bonds, who, along with Nadeau, is considered the least secure incumbent in an election cycle that favors most sitting elected officials, has struggled to raise money at the same rate as some of her fellow council members.

The biggest spender of the last quarter was a surprising one: Bowser, who faces no strong opponents in the primary. The mayor’s campaign spent $691,000, according its financial report.

Bill Lightfoot, Bowser’s campaign chairman, said the mayor’s prolific spending in the virtually uncontested race was intended to highlight her agenda for voters.

“It’s really her trying to get her message out, making sure people understand there’s a reason to vote for her. Even though she doesn’t have a credible opponent,” he said. “She does expect to be mayor, and she wants to have people buy into her program and realize there’s a reason to be optimistic and be hopeful.”

The campaign report for Bowser states that $408,000 was spent on advertising and $194,000 on consulting fees, along with $71,000 on postage.