After a promising start, results were very much up and down until the final phase of the season where Colin's young side strung together five wins out of eight with two draws.
The Scot admits that ultimately, it is disappointment to him that results did not come sooner to enable a challenge for the league. His side finished in sixth place with Watford emerging as champions.
"Overall I am slightly disappointed that we weren't further up the league," said Colin. "As with all these things it is a development, but I felt we had good enough teams to get better results - especially in the middle part of the season where we didn't collect anything near the wins or draws we should have expected of ourselves.
"There were maybe three occasions in the season where we weren't at it."
Unlike in his first season back at the club, Colin had a squad to work with in his second - the graduates from the successful under-19 team that reached the semi-final of the FA Youth Cup.
"Having the young ones as a group was the most enjoyable part of it and I've seen quite a bit of progress from them.
"We had a nice end to the season.
"Most of the teams we've matched and been more than capable of beating. Unfortunately, individual mistakes or lack of concentration has let us down and cost us goals.
"That's what I've found, some of the goals we've given away have been quite nonsensical really. If it was a first team game you really would have been pulling your hair out.
"You've got to accept that the boys are trying to do the right things and slips of concentration happen. As long as the mistakes decrease then you are seeing an improvement."
Colin Calderwood reflects that he witnessed considerable progress from his reserve team group over the course of last season.