In Dutch when we talk about years, hours or quarters and they are preceded by a numeral like two, three, how much, a few, so much etc we write it in singular.
E.g. Twee uur, drie kwartier, tien jaar. Een paar jaar, zoveel uur per week etc.
Words like some and many don't fit in this category. So many years = vele jaren, some years = enkele jaren.
You can say 'tien jaren' but then the context changes. If you say it like that you usually mean a specific time period in which something (unpleasant) has happened.
I hope this makes it a little clearer for you
PS. I think the Dutch sentence is a little strange. I would say: 'De stad zal binnen tien jaar veranderen.'
Not sure but i noticed it's the same with hours.. 10 uur.. Maybe it's a time thing