Hopes that a decision on plans for the Long Stratton bypass would be made later this year look to have been dashed - amid the nutrient neutrality issue which has left housing schemes in limbo.
Planning applications for the road, linked to the construction of 1,800 new homes in the area, are among those held up by a directive by government advisor Natural England.
The public body said councils could not approve plans involving 'overnight accommodation', until they could prove they would not lead to more nutrients flowing into waterways in the catchment of the River Wensum and Norfolk Broads.
Work is under way to find ways for developers to mitigate for pollution from developments which can harm habitats, following the directive from Natural England.
That includes a nutrient neutrality calculator, so developers can figure out how much pollution their schemes would produce - and what they would need to do to counter that.
That would include 'buying' credits for mitigation such as new woodland and wetland schemes.
However, council bosses hoped bigger developers might be able to outline how they would provide their own on-site mitigation before that scheme is up and running - so decisions on those could be made later this year.
Bosses at South Norfolk Council had hoped they could get a decision on the housing plans connected with the Long Stratton bypass this year, but concede that now looks unlikely.
Phil Courtier, director of place for South Norfolk and Broadland councils, said: "We're hoping that early next year we can have some of the bigger schemes coming forward.
"We'd hoped we might get the Long Stratton bypass before a committee by the end of this year, but we had meetings recently and that is unlikely to happen."
Mr Courtier said that was not down solely to the nutrient neutrality issue, but was also because of ongoing negotiations.
The cost of the Long Stratton bypass has gone up from £37.4m to £46.2m, due to delays, inflation and the war in Ukraine.
Natural England says stopping nitrogen and phosphates from entering waterways is important because they reduce oxygen in the water, making it harder for aquatic species to survive.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here