This is the record of a decision taken in 2014, kept where people can find it because the mark on the site has not always looked the way it does now. The domain came first, and the logo came second. We worked through three prototype styles, put them to a vote, chose one and then revised it, and all four of those drawings are below.
The Three Prototypes
Option One
Option Two
Option Three
The vote came out an even split between the first and the second. Option one offered simplicity, no gradient and a flat treatment, which made it easy to place onto promotional material without fussing over the background. Option two had more of a fun and professional feel, and the placement of the green worked well, but the B and the C were crammed together far enough that people reading it for the first time took them as DC. That single problem decided the revision.
The Revision
We kept the second direction and fixed the thing that made it hard to read by pulling the two letters apart. That revised mark is the one the council has used since, and the earlier drawings survive on promotional samples from the first year. If you have ever wondered why four versions of the logo are floating around, this is why: three were never chosen, and the fourth is the one on the header.