The Signature Theater’s production of “Urinetown” was a clear hit with the Helen Hayes Award judges, drawing 12 noms, including resident musical. Judges for the annual D.C. legit awards also appeared eager to sprinkle noms among the smaller houses, including tiny Rep Stage and the American Century Theater.Among playwrights, Sarah Ruhl received nominations for “The Clean House” and “Passion Play,” which premiered here at the Woolly Mammoth and Arena Stage, respectively. Ford’s Theater received six noms for its production of “Big River: The Adventures of Huckleberry Finn.” Roughly half of the D.C. area’s professional theaters increased their audiences last year, but reduced bookings at the National and Warner theaters helped cut overall attendance by 8.5%, according to figures released by Linda Levy Grossman, exec director of the Hayes Awards, during a Tuesday press conference to announce nominees. Some 56 professional theater companies in D.C. presented a total of 348 productions during 2005, drawing 1.9 million people to 7,169 performances. While 48% of them reported increased auds, 37% saw smaller houses, according to the annual theater tally. The D.C. theater kudofest, in its 22nd year, will be held April 17.