But environment groups have strongly opposed the bill, which Forest and Bird argued was so badly drafted it would also exempt the two councils from every other law in the country.
"Mangrove destruction would be taking place outside the law," said the group's spokesperson Dr Rebecca Stirnemann, who appeared before a select committee at Parliament today.
Forest and Bird pointed out that a clause in the bill would mean that any law not expressly over-riding the Mangroves Management Act wouldn't apply to mangrove removal activities.
"This means that the Conservation Act, Wildlife Act, Hazardous Substances & New Organisms Act, Employment Relations Act and the Health and Safety at Work Act won't apply to mangrove removal under the control of these councils," Stirnemann said.
She further argued the bill was "completely inadequate" to manage coastal ecosystems.
"The purpose of the bill is biased towards mangrove removal in favour of 'amenity values'.
"It does not recognise the importance of mangroves as wetlands, habitat for native birds and fish, and in protecting our coastal communities from erosion and storm surges."
Stirnemann said the bill was "about single-minded opposition to an important coastal habitat, not about rational, scientifically informed mangrove management".
"Mangroves aren't responsible for sandy beaches turning into muddy estuaries. Mangroves move into new areas when sediment flowing down rivers creates the right environment for them."
"Destroying the mangroves won't bring back the beaches. If this council actually cared about managing mangroves they would address the cause, not just take a chainsaw to the symptoms. This is last-century thinking, which in an age of climate change is truly dangerous."
A raft of other people and parties have also lodged submissions.
The Department of Conservation noted in its submission that the bill made no requirement for the consideration of birdlife - which would be affected positively and negatively - nor did it have any requirements around obligations under the Ramsar Convention on Wetlands.
Waikato University warned that "mangrove clearance will not halt mangrove expansion in estuarine environments since none of the causes for mangrove proliferation will be taken away".
The Environmental Defence Society described the bill as "a knee-jerk reaction to local complaints around the aesthetics of mangroves, dressed up as a bill to support retention of habitat for seabirds".
Other local residents and groups have supported the bill.
"The ability to allow local communities to draft their own plan for mangrove management is essential for the future use of our waterways," the Thames Sailing Club stated in its submission.
"The safe navigation of our waterways has been endangered by the continual growth of the mangroves which have narrowed the streams and changed flow patterns and depths."
Whangamata Community Board chairperson Ken Coulam said: "In short, the existing mangrove management regime under the Resource Management Act 1991 has been costly, time-consuming, divisive, and has not delivered noticeable desirable outcomes."
