As the threshold for the use of EIA on residential schemes is about to be lifted, and the impetus to regulate the inclusion of health continues apace, focusing in particular on its integration with Environmental Impact Assessment (EIA), it's perhaps worth illustrating what EIA was created for in the first place...in order to highlight what it is not useful for.
Which is the 'odd one out' below?
The answer is the bottom right: the urban extension. All the others are single-use projects. There's no doubting that all will have either a significant or a very significant impact on the environment, but the urban extension is a complex mixed/multi-use proposal that involves lots of people making lots of decisions every minute of every day. Environmental Impact Assessment was created to mitigate negative impact (e.g. ostensibly by moving endangered species out of the way). It is not a design tool. It can not help plan a healthy sustainable and resilient neighbourhood. It certainly can't ensure that the landowners and developers take their responsibility seriously. Neither can SEA, and neither, I fear, will HIA.