He has been made Knight Companion of the New Zealand Order of Merit for services to environmental law.
Sir Peter was appointed as an Environment Canterbury Commissioner in 2010 and helped to drive the development of Christchurch's post-earthquake Land Use Recovery Plan, and the Canterbury Water Management Strategy.
He was instrumental in establishing the Resource Management Law Association in 2002 and was a founding member of the Environment Institute of Australia and New Zealand.
An associate professor of resource management law at Lincoln University from 2000 to 2005, he presided over hearings by Environment Waikato concerning the control of nitrates entering Lake Taupō, and advised the government on the Resource Management Amendment Bill in 2009.
Sir Peter served as an Environment Court judge from 1978 to 2000 and was appointed as the inaugural Chief Freshwater Commissioner in 2020.
He told RNZ he received the letter informing him of the honour in November and it took him a few days to recognise its significance.
"I was very surprised."
His work as a member of the Canterbury Regional Council and the post-quake recovery was a highlight of his career, he said.
"I'm a Cantabrian born and bred, and I'll always have a deep interest in Canterbury, and in particular in Christchurch. It's my home town and I'm thrilled to see how it's developing now as a result of the recovery process.
"It's going to be a really beautiful city."
Sir Peter acknowledged current Speaker of Parliament - and then Ilam MP and Canterbury Earthquake Recovery Minister - Gerry Brownlee, saying they had worked closely together after the quakes.
"I don't think many people fully appreciate the tremendous amount of effort that Gerry Brownlee put into getting Christchurch back on track and getting it developed into the city it now is."
Water management had introduced him to a wide range of people and he had made many friends, Sir Peter added.
"[We] did a lot of good work, particularly with the farming community."
Lyttelton Port's post-quake recovery was critical to the South Island economy, he said.
"Throughout all that I've had a lot of very dedicated people who worked with me. I might have done a bit of the leading but a lot of other people contributed to the successful outcomes."
Sir Peter's advice to anyone interested in pursuing a career in environmental law was to keep up with the changes in the sector.
"It's a very rewarding area of the law to practise in because it's talking about what's going to happen in the future, rather than picking up all the broken pieces from the past."
