D.C. CFO Natwar Gandhi is raising the alarm that the District is precariously close to surpassing its self-imposed 12 percent debt cap, and urging that any additional borrowing be curbed. Gandhi’s warning comes at the same time Mayor Fenty is putting the final touches on his proposed spending plan for FY2011. The city is already facing an estimated $500 million budget gap next year. “I urge the Mayor and Council to carefully evaluate the need…