The government has announced that the flood waters really are coming to central Bangkok (although not central-central Bangkok) and are due to arrive over the course of the next 24 hours.
The subway service is closed and many shops and houses are sandbagged or else have concrete screens built around doors and other vulnerable points. Supermarkets and convenience stores have been a little low on stock of some products for the last couple of weeks but that is likely to intensify today – there is probably a need for bottled water, for example, since it is likely that industrial waste is going to enter the general water supply.
Whether electricity supplies can be maintained remains to be seen. Authorities have promised they will be but there are occasional power cuts even in the best of times so it would not be a big surprise if something goes down because someone crashes into a power line or some such thing.
Certain people seem to think Bangkok will turn into the Lord of the Flies within a couple of hours but I doubt it will be as bad as that – then again, what do I know about anything?