Exclusive: Chris Hinchliff urges environment watchdog to block rules that will allow almost 16,000 new homes in one of UK’s most protected areas

The environment watchdog is being urged to intervene in “cash to trash” planning rules that will allow almost 16,000 new homes in the Norfolk Broads despite the damage to one of the UK’s most environmentally protected areas.

Labour’s flagship planning reforms allow damage to protected habitats and species to be overlooked if developers pay into a central nature restoration fund, which is used for conservation actions at a later date. These environmental delivery plans (EDPs) have been called “cash to trash” by critics, who say they roll back decades of environmental law and are a “licence to kill nature”.

So far not a single target of the plan has been met. As negotiators convene for Cop17, the pressure is on to find a way to honour the commitments made at previous summits

• Cop17 at a glance: everything you need to know about the UN’s nature summit

Passersby could smell the dead fish before they saw them. In August, more than 3,000 pike, roach, carp and rudd were found lifeless along the River Wensum in Norwich. Some gasped for air in their final moments, desperate for the oxygen that heatwave conditions had depleted in the water. Investigators believe that the die-off was triggered by heavy rainfall that flushed through high concentrations of pollution at a time when wildlife were already struggling.

The 45-mile (70km) chalk river is one of about 250 in the country. They are a geological accident almost unique to Britain – and one of Earth’s rarest habitats. They emerge from chalk aquifers and are home to species such as freshwater shrimp, otters and stoneflies, also providing drinking water for millions of people. But just 11 have formal protection, with many ravaged by sewage pollution and overextraction. The Norfolk river is one of the few that does have legal protection, but it is in poor ecological health.