i have kept/keep chickens on both council and (currently) private allotments. did get some resistance from council run one but ask about by-laws and to see it in writing, and they run a mile because most of the people who run them don't have a clue - i've challenged them, believe me.
sadly though, I did have to remove my birds (through choice not forced)from council site because of kids breaking in an nicking some birds and equipment. really annoyed me but led to me finding a private site, which is great by the way. the guy that owns them loves livestock being on there and so I have both hens and cockerels. i currently have a whole plot fenced for my birds and am in the middle of completing a second for ex-bats in january. i do have 3 plots there, so using one for veg in summer.
other people on the allotment are fascinated with chickens and feed them (greens) etc. many want manure and ask to buy eggs. productive all round! my friends also keep geese/chooks there and another bloke horses.
as for the everyday commitment, of course you do, whatever the weather. all part of caring for your stock! i remember being there Christmas day lasy year and it was so peaceful. mind you, i'm lucky because i have to pass my site on the way to and from work, so very convenient.
my uncle keeps his birds on a managed council site and they have a limit of 8 birds maximum. this was enforced because of past neglect by other tennants overstocking.
I live in a built up area so don't let the break in thing put you off, it happens a lot round here by me. but be prepared wherever you live! good luck!