On-site mitigation is thought to be frequently used on larger developments.
However, concerns have been raised as to the ecological practicality and longevity of on-site mitigation when used indiscriminately. There are now suggestions that in some cases on-site mitigation proposals can be ecologically dysfunctional and are over-positively represented by the statutory metric. Furthermore, concerns over the lack of monitoring for on-site mitigation are now well accepted as a “missing link” in the BNG Framework relying instead on individual LPAs to voluntarily detail monitoring requirements in a development’s s106. Of course more such monitoring responsibilities cannot be popular with any LPA where resources are already overstretched to comply with their existing BNG Framework obligations.
With the above in mind, which developer would not choose on-site mitigation? Who would not, when nothing is set up to enforce it’s 30-year implementation and where the obligation can also be passed on to the property management companies to maintain these habitats? This of course will impact the new owners of the houses/properties if eventually enforcement action is taken to manage the habitats. Some consider this to be a “ticking time-bomb” for conveyancers who may have overlooked the implications of BNG on their clients buying such property, but also ultimately LPAs who perhaps need to consider a more realistic approach to their implementation of the BNG Hierarchy.
We know that such on-site mitigation is encouraged because of the mental/physical health benefits, alongside the potential for flood mitigation.
However, any site used for biodiversity needs to be capable of creating and sustaining the improved habitat, otherwise, all the many benefits that come from BNG are irrelevant.
This will, in my opinion, not be achieved when sited in areas of high population using habits that are vulnerable to human interference without the type of mandatory powers of enforcement found on off-site habitats. Already there have been cases of residents interfering with on-site mitigation and in doing so jeopardising the creation of BNG. A report from ‘Wild Justice’ and commented on in ‘The Conversation’, see link below, however biased this may or may not be, illustrates that this issue is not likely to go away.