The Hawke's Bay Regional Council's strained relationship with the Hastings District Council over a number of years was raised at the third day of the Havelock North water inquiry yesterday.
Throughout the morning, former Hawke's Bay Regional Council group manager resource management Darryl Lew, who was in the role when the 2008 Hastings District Council resource consent to use the Brookvale bores for a water supply was granted, gave evidence.
He was asked whether there was enough communication and information sharing between the likes of regional councils and district councils acting as municipal water suppliers.
Mr Lew acknowledged there was often a gap in information sharing, but stressed regional councils monitored the state of the environment with a focus on the sustainability of water, surrounding its quantity, rather than drinking water quality.
"This is problematic - these agencies are creatures of statute - their day-to-day work is so busy they do not see the links."
At issue in general terms was at what point a regional council was compelled to apply national environment standards for sources of human drinking water when permitting activities in a regional plan.
Counsel assisting the inquiry Nathan Gedye said the Hawke's Bay Regional Council had not been told about a contamination event in 2013 at Anderson Park, nor another at Bore 3 in October 2015.
"If you have two events like that and tell the regional council then it has the information to assess whether it would adversely affect the water?"
Mr Lew agreed that this was an example of the information gap that had been highlighted.
Mr Gedye asked if district councils had a "big brother" perception of regional councils, which could use their regulatory power against them.
Mr Lew noted that even in his time (2007-2011), and beyond, the relationship between Hastings District Council and Hawke's Bay Regional Council was strained, not only to do with drinking water but also storm and wastewater, because there was some non-compliance involved.
He said his approach was that the Hastings council had to respect that the regional council had to enforce its regulatory function, and that if they were having difficulty complying with any consents, if they did not think they were correct or pragmatic, they could put forward applications for change.
The E. coli contamination of Bore 3 in September 2015 was also revisited yesterday, with HBRC principal groundwater scientist Dougall Gordon answering questions about the Hawke's Bay Regional Council's response to the incident.
Mr Gedye quizzed Mr Gordon about the prospect that activity at Te Mata Mushrooms may have contributed to presence of E. coli, and whether it was possible there was aquifer contamination under Bore 3.
Mr Gordon said that at the time Te Mata Mushrooms was one of a range of issues, including the impact of other bores in the area, and his focus was on getting information for a Tonkin and Taylor investigation commissioned by the Hastings District Council.
At that time, he said he was comfortable that the issue was localised to Bore 3, despite a regional council state of the environment test bore situated about 225 metres away from Bore 3 showing high levels of E. coli when regular quarterly testing was later carried out in December 2015.
This bore had had ongoing E. coli readings since 2008, something Hastings District Council water services manager Brett Chapman told the panel earlier this week the Hastings council was not aware of until the 2015 contamination.
Since December 2015 there had been no presence of E. coli in that test bore in subsequent testing carried out the following year.
At this point, the inquiry is looking at what the authorities knew about the risks to drinking water safety before the August gastro outbreak, the source and cause of the water contamination, and whether any person or organisation was at fault, and whether there were any systemic failures.