Urban Demonstrator: Strategic Roads & Water
Final Report prepared for Defra
Pollution from road runoff is episodic and dependent on antecedent conditions. The main toxic pollution comes from metals and PAHs. Levels of these toxins can be significant and there is evidence that they cause localised ecological damage. However, evidence that road runoff is causing significant catchment scale damage, due to water quality, is limited as the location and monitoring frequency rarely captures the episodic impact of highway runoff.
There is evidence that road runoff causes localised hydromorphological damage to the landscape due to locally accelerated erosion, particularly in headwater catchments where the relative scale of change is more significant. Mitigation measures for water quality issues caused by roads can be simple and effective and will often be aimed towards mitigating these hydromorphological imapacts.
This report sets out the risks associated with highway runoff from the Strategic Road Network in Devon and Cornwall and the potential opportunities to adopt a Payments for Ecosystem Services-based approach to mitigate them. Through this pilot a direct dialogue with Hightways England, both locally and nationally, will now facilitate taking the specific issues identified forward via the Environment Designated Fund. Further discussions are now planned with HE and local landowners to explore specific opportunities further.