This has also been one of my primary goals - an online resource representative of our collective knowledge as government employees. As an engineer/public works director, this is really my area of focus within the overall organization. But as you have indicated, we could all benefit from a wiki that offers a more comprehensive coverage of government services and resources.
I have discussed setting this up within our MuniGov group and have talked to our national public works organization about doing something focusing on public works, but so far we have yet to start any actual site. Perhaps I can now use your site as an example to help encourage them to begin one for local government in the US. Thanks for offering this information!