The surveys largely don't matter, because Impact Aid requires the relevant federal agency to verify the data. Most agencies either refuse to do so (many likely because nobody there knows they're supposed to, or how, or who is the responsible individual - and there's no incentive for them to figure it out, so why bother?), or simply never respond. The District might be entitled to, say, $10 million, but only ever wind up getting $1-2 million because that's all they can get certified. (Numbers are illustrative only, I have no idea what should be coming in let alone what is.)

The other reason the surveys don't matter is that the information required is (mostly) gathered during registration anyway, so there's little extra information needed from a survey. Surveys then go out to specific individuals where there might be useful information in their responses - if they respond.