Supporters of a TIFIA-like program for water projects inadvertently let the cat out of the bag this month when, in response to their WIFIA pilot program, the Joint Tax Committee and Congressional Budget Office prohibited the coupling of a federal loan with tax-exempt bonds for the same project.

When asked why they had not imposed the same constraint on the TIFIA program during the passage of MAP-21 last year, the budget experts reportedly said it was an inadvertent mistake that they would fix in the next highway reauthorization in 2014.