Assessing and protecting groundwater dependent habitat in Scotland using EIA

13th October 2015

Related Topics

Related tags

  • Pollution & Waste Management ,
  • Water ,
  • Skills ,
  • Guidance ,
  • CPD


Gavin Tivey

Gordon Robb, technical director at SLR Consulting, outlines assess potential impacts of development on water dependant habitat.

In addition to other statutory duties, the Scottish Environment Protection Agency (Sepa) has a responsibility to safeguard abitats sustained by groundwater, known as groundwater dependent terrestrial ecosystems (GWDTE).

Development, and in particular ground excavation, which can effect groundwater flow paths and groundwater quality has the potential to impair areas of GWDTE which are protected by the EU water framework Directive.

Without appropriate design or mitigation, excavations can intercept the groundwater table and divert groundwater flows away from areas of GWDTE or construction activities can introduce materials such as concrete or aggregate that can alter local groundwater chemistry and directly or indirectly impair GWDTE.

Assessment approach

In order to assess potential risk to GWDTE, Sepa has issued guidance to developers and for their advisors.

Sepa requires, as a minimum, a phase 1 habitat survey to be undertaken and provided as part of a planning application. The survey is used to identify wetland types. If it suggests that GWDTE may be present at or near a site where excavation is proposed then a national vegetation classification (NVC) survey also needs to be provided.

Buffers of 100 metres and 250m around areas of GWDTE are proposed by Sepa for excavations up to 1m and greater than 1m respectively. If development within these buffers is proposed then a detailed qualitative / quantitative assessment is required. This should be used to assess whether the development proposals will impact on the GWDTE, whether mitigation measures can reduce the significance of impact or whether the development proposals need to change to ensure no impact on the GWDTE.

Application of EIA to assess areas of GWDTE

As part of an EIA, much information is gathered to assess baseline conditions at the site and in its immediate surrounds. Typically there is a lot of information that can be used to characterise the site's geology, hydrogeology and hydrology, all of which are relevant in assessing GWDTEs. In addition, many sites will also have much information which can be used to characterise with confidence the habitats at and adjacent to the site. These sources of information can be used together to develop a conceptual site model (CSM) to complete an initial assessment of the likely presence and sensitivity of GWDTE.

Screening using NVC mapping can be used to identify areas that are more likely to have wetland habitats sustained by groundwater, for example, NVC types M6, S11, W4, CG11 and U17. Combined with the CSM, the initial GWDTE assessment can be refined.

Where the potential presence of GWDTE is identified through hydrogeological conditions and NVC mapping, developers can either apply SEPA's recommended buffers and/or undertake further assessment to confirm whether that identified habitats are in fact sustained by groundwater or not.

This screening approach, which is embedded in EIA methodology, allows appropriate time and resource to be invested when assessing GWDTEs.

There are number of methods that can be used to assess further and in greater detail areas of potential GWDTE. SLR has combined interpretation and assessment by ecologists, geologists, hydrogeologists and geochemists very successfully to assess the ground conditions near areas of GWDTE, potential groundwater flow paths and water quality to accurately delineate the contribution of different water sources to areas of possible GWDTE.

In a number of instances, SLR has been able to confirm that the potential GWDTEs are in fact sustained by surface water rather than groundwater, thus removing potential development constraints.

The EIA approach to assessment of areas of potential GWDTE also allows appropriate mitigation measures to be identified to maintain or improve GWDTE. For example, measures that maintain existing surface water or groundwater flow paths can be identified and specified. An understanding of the site ecology and geochemistry recommendations can be used to ensure that aggregate or concrete used on site will not locally alter groundwater quality.

An EIA approach to site assessment provides a very useful screening and scoping tool to assess potential impacts of development on water dependant habitat. The combination of common EIA disciplines can quickly develop a CSM which can be used as a screening tool to identify where further assessment is required. The same disciplines can be used to design additional site investigation, assess findings and identify appropriate mitigation measures to safeguard areas of GWDTE and groundwater resources.


Subscribe to IEMA's newsletters to receive timely articles, expert opinions, event announcements, and much more, directly in your inbox.

Transform articles

Latest environmental legislation round-up

Regulatory gaps between the EU and UK are beginning to appear, warns Neil Howe in this edition’s environmental legislation round-up

4th April 2024

Read more

Around 20% of the plastic recycled is polypropylene, but the diversity of products it protects has prevented safe reprocessing back into food packaging. Until now. David Burrows reports

3rd April 2024

Read more

A hangover from EU legislation, requirements on the need for consideration of nutrient neutrality for developments on many protected sites in England were nearly removed from the planning system in 2023.

2nd April 2024

Read more

Campaign group Wild Justice has accused the UK government of trying to relax pollution rules for housebuilders “through the backdoor”.

14th February 2024

Read more

Stella Consonni reports on the existing legal framework and the main challenges

15th January 2024

Read more

David Burrows on the stolen concept of a circular economy, and how reduction must be at the heart of product design

30th November 2023

Read more

Zero Waste Scotland is focused on closing the energy sector’s circularity gap. Kenny Taylor reports on progress so far

28th November 2023

Read more

Media enquires

Looking for an expert to speak at an event or comment on an item in the news?

Find an expert

IEMA Cookie Notice

Clicking the ‘Accept all’ button means you are accepting analytics and third-party cookies. Our website uses necessary cookies which are required in order to make our website work. In addition to these, we use analytics and third-party cookies to optimise site functionality and give you the best possible experience. To control which cookies are set, click ‘Settings’. To learn more about cookies, how we use them on our website and how to change your cookie settings please view our cookie policy.

Manage cookie settings

Our use of cookies

You can learn more detailed information in our cookie policy.

Some cookies are essential, but non-essential cookies help us to improve the experience on our site by providing insights into how the site is being used. To maintain privacy management, this relies on cookie identifiers. Resetting or deleting your browser cookies will reset these preferences.

Essential cookies

These are cookies that are required for the operation of our website. They include, for example, cookies that enable you to log into secure areas of our website.

Analytics cookies

These cookies allow us to recognise and count the number of visitors to our website and to see how visitors move around our website when they are using it. This helps us to improve the way our website works.

Advertising cookies

These cookies allow us to tailor advertising to you based on your interests. If you do not accept these cookies, you will still see adverts, but these will be more generic.

Save and close