Garry confirmed he received the notice of resignation following the council meeting.
Due to the approaching end of elected members' three-year term later this year, staff will now prepare a report for council seeking a decision to either fill the vacant Maungatautari ward seat by appointment or leave the position vacant until the upcoming October elections.
With less than 12 months until the elected member's three year council term ends, a by-election will not be considered as part of the options.
A decision on the report is expected to be made at the May council meeting.
Elwyn chairs the Maungatautari Reserve Committee, sits on the Cambridge Community Board as Maungatautari ward councillor, is a member of the Heritage Fund advisory group and is part of the Waikato-Tainui and Waipā District Council Joint Management Agreement.
Jim said the resignation was regrettably the best outcome in the circumstances.
"I am grateful that Elwyn has taken this step in the circumstances and I genuinely believe it will be the best outcome for both Elwyn and council," says Jim.
"I would like to acknowledge Elwyn's many years of contribution to council on behalf of the residents of Maungatautari.
"I would also like to reassure our Maungatautari residents that myself and the rest of the Waipā councillors are happy to receive any questions or concerns that they would otherwise direct to Elwyn at this time. We recognise this may be unsettling and we are here for you."
The resignation comes following scrutiny of the on-farm sand quarry was brought to council's attention on April 1.
Under council's District Plan rural zone rules, farm quarries are a permitted activity in the rural zone for that farm's use.
When council's enforcement team was notified of the size and nature of the quarry, staff undertook an investigation and suspended operations on the site immediately.
A retrospective resource consent application for the operation has since been submitted to council, which will rely on an independent processing planner and independent commissioner to decide on its outcome.
The status and progress updates of the consent will be loaded onto the council's Consents of Interest webpage at www.waipadc.govt.nz/consentapplicationsofinterest.