The Vancouver Symphony Orchestra will have to cancel its 2011-2012 season unless it can raise $100,000 before month’s end, the group’s board of directors says.

In an open letter posted on the orchestra’s website, the board attributes the group’s financial Sturm und Drang to the recession-driven decline in individual donations and corporate sponsorships currently affecting many nonprofit organizations. Contributions, “especially business and corporate support,” have fallen 15 percent each of the last three years, the board writes, and the orchestra’s annual fundraising event last month “fell short of expectations.” Ticket sales have remained constant—but they cover just a fifth of expenses.

The orchestra’s directors vow that if the group can fund what would be its 33rd season, it will emerge from this budget crisis a much leaner organization, with an administrative budget less than half its current size and a schedule heavier on economical chamber-sized performances.   

The orchestra will present two donation-based benefit concerts at Trinity Lutheran Church (309 W 39th Street, Vancouver) this weekend, one at 7 pm Friday and one at 8 pm Sunday.