CARLSBAD -- The Children's Discovery Museum of North San Diego County must pay off $15,000 in debt by the end of August or the nonprofit organization might lose its downtown home, its leader said this week.

"A lot depends on how it goes over the next couple months," said Marietta Rogers, the museum's executive director.

The museum moved into its current location in a city-owned warehouse at State Street and Christiansen Way nearly three years ago. At the time, the change was much celebrated because the new, 6,300-square-foot site was more than double the size of the museum's old home in the Village Faire Shopping Center several blocks away.

But admissions slumped last year and the organization fell behind in its rent payments, Rogers said.

The organization missed one $3,155 monthly rent payment in April, then missed multiple payments in the fall, said Debbie Fountain, the city's director of housing and redevelopment. Since that time, she said, the organization has paid its rent on time, but hasn't settled the old debt.

In recent weeks, Rogers has met in closed-door sessions with the City Council to see if the city would forgive the debt. The city hasn't done that, but officials have given the museum until the end of August to resolve the matter, she said.

If the museum doesn't pay its $15,000 debt by then, the museum could find itself in trouble as it tries to renegotiate its lease, Rogers said. The museum's three-year lease is up in October, and the organization has the option of seeking a one-year extension at that time.

Fountain confirmed that the city had given Rogers a deadline of Aug. 31, but said city officials will be flexible about extending the lease as long as the organization is making significant progress in paying back the debt.

Rogers said her organization plans a series of fundraising events in the months ahead. They include the museum's 11th birthday celebration April 1, an ice cream social in June, the annual bubble festival in July and a water play day in August.

It isn't surprising that last year was a tough one for the organization because the second year in a new location is always slow, Rogers said.

"The first year they open, there's a big rush," she said. "Everybody wants to see the place. … The second year is the pits."

The old location had an annual attendance rate of 30,000 people, but figures for last year in the new location were roughly 3,000 less than that, she said.

Neither museum officials nor the city consider the current location on State Street to be the museum's permanent home. Museum officials plan to eventually move their facility to a site at Quail Botanical Gardens in Encinitas, but that effort may be delayed by the current financial difficulties, Rogers said.

The city wants the museum's current location for a downtown redevelopment project, "which is why we said we're only interested in short-term leases," Fountain said.

Contact staff writer Barbara Henry at (760) 901-4072 or bhenry@nctimes.com.

Children's Discovery Museum of North San Diego County

Hours: 10 a.m. to 4 p.m. Tuesday through Saturday; noon to 4 p.m. Sunday

Location: 2787 State St., No. B

Admission cost: $6 per person for anyone over age 2.

Web site: www.museumforchildren.org

11th birthday party:

Time: 10 a.m. to 5 p.m. April 1

Admission: Regular $6 price

Activities with set times: 1 p.m. cake cutting, 2 p.m. puppet show, 3:30 p.m. magic show

Other activities: Spin art, face-painting, sand creations, Hula-Hoop contest (some activities cost extra)