Purple Haze Minerals Site, Hampshire
Using long-term ecological planning to reduce risk, cost and delay.
Project overview
Purple Haze is a c.70ha allocated minerals site in Hampshire, proposed for extraction over a 25-year operational period. Despite allocation, the site presents exceptional ecological and environmental sensitivities, including designation as a Site of Importance for Nature Conservation (SINC), adjacent to the Dorset Heaths Special Protection Area (SPA), potential hydrological connectivity with Ebblake Bog, and a mosaic of wet and dry heath habitats.
The site supports a nationally notable invertebrate assemblage, the rare plant coral-necklace, breeding nightjar (with the site forming functionally linked habitat to the SPA), and all six native reptile species. The principal challenge has been to demonstrate that mineral extraction can proceed without unacceptable ecological or hydrological impacts, while avoiding repeated survey cycles, redesign, and regulatory delay.
A proportionate, long-term ecological approach
Since 2019, we have supported the Purple Haze project through a managed, evolving ecological evidence base, aligned with quarry design, hydrological modelling and planning strategy.
Rather than treating ecology as a one-off planning requirement, the approach has focused on early risk identification, followed by targeted updates only where they materially affect decision-making.
A comprehensive baseline was established early in the project, covering habitats, protected and priority species, invertebrates, birds, reptiles and mammals. This ensured that ecological constraints were clearly understood from the outset and avoided later scope creep or seasonal delays.
As the scheme evolved, surveys were selectively updated to maintain data validity and respond to emerging issues, including recreational pressure, Biodiversity Net Gain (BNG) requirements and hydrological risk. Importantly, some surveys were justifiably not repeated where habitat change and scheme design meant further data would not alter mitigation or outcomes. This avoided unnecessary expenditure while maintaining a robust and defensible evidence base.
Integrating ecology, hydrology and design
Hydrology has been the principal technical constraint on the project, particularly in relation to potential impacts on Ebblake Bog and areas of irreplaceable mire habitat. Ecological input has therefore been closely integrated with hydrological assessment and quarry design, ensuring that mitigation, phasing and restoration proposals are realistic and deliverable.
Close working with hydrologists, engineers and planners has reduced the risk of late-stage redesign and provided regulators with confidence that ecological issues are fully embedded within the wider scheme.
Managing policy change, SINC offsetting and BNG
During the lifetime of the project, the Hampshire Minerals and Waste Plan has been revised, requiring proposals to be tested against an evolving policy framework. By maintaining an up-to-date ecological evidence base and engaging early with the Local Planning Authority, the project has remained adaptable to policy change without the need for wholesale re-survey or redesign.
A key planning risk has been the requirement for long-term SINC offsetting, delivered alongside mandatory BNG. We assessed both the site and offset areas using UKHab and Defra Metric 3.1, demonstrated how design evolution reduced impacts over time, and phased compensation to reflect quarry progression. Early agreement with the LPA avoided over-commitment at the outset and reduced long-term financial exposure.
The outcome
Although hydrological complexity has extended the project timeline, ecology has not been a cause of avoidable delay. Instead, the approach has delivered:
- Lower lifetime survey costs through proportionate updates
- Reduced redesign and mitigation rework
- Clear and constructive engagement with regulators
- A defensible and policy-compliant planning submission
- Certainty over long-term ecological liabilities
Purple Haze demonstrates that on complex and sensitive sites, early, continuous and proportionate ecological input is not a cost burden. It is a risk management tool that protects programmes, budgets and consent outcomes.
For further information contact:
Laura Grant BSc (Hons) MCIEEM
Associate Director, Ecology by Design Ltd
Tel: 01865 893348
Mob: 07495 00213
