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Pre-works Walkovers: A Case Study

Pre-works walkovers

Like all ecological consultancies, Purple Plover takes on a range of different project types. Some are fairly long-term Ecological Clerk of Works (ECoW) briefs. Others, though, are one-off ecological surveys such as pre-works walkovers or vantage point surveys. A recent project in Orkney, for example, involved pre-works surveys across the archipelago. Here we surveyed for protected species, as well as anything else the client needed to be aware of from an ecological point of view. To all intents and purposes, this sounds fairly straightforward. However, there are always a number of considerations to take into account with any project, and this was no exception. So, let’s find out exactly what is involved when carrying out pre-works walkovers.

Logistics, Logistics, Logistics

Being based in the Highlands of Scotland means logistics are sometimes more complicated than they are elsewhere. Many of the sites we work on are quite remote or at least not straightforward to get to. This particular job involved visiting 11 different islands including Orkney Mainland within quite a tight deadline. Planning was therefore key to ensure the work was done efficiently. Ferries between the islands are extremely reliable in our experience. However, they are on a timetable that is great for tourists wanting to spend a full day on an island, but less good for contractors wanting to visit as many islands as possible within a short space of time!

Hoy Ferry
The ferry to Hoy, just one of many ferries we used on this job

In addition, to get to the survey site on Papa Westray, we had to book the 12-minute inter-island flight as ferries just weren’t going to work for us at all. As this only has 8 seats, finding a spot during the tourist season was easier said than done. After a fair bit of head-scratching, though, we managed to arrange an itinerary that got all the work done and left a bit of wiggle room as a contingency. Once we received survey site locations, we were also able to work out whether any could be done without a car to save the client unnecessary expenditure. Of course, non-island-based surveys are usually much easier to plan. The opportunity to visit a number of islands that we hadn’t been to before definitely made up for the logistical headaches, however.

Papa Westray plane pre-works walkovers
Planes, ferries and automobiles….
Papa Westray Airport
Papa Westray Airport isn’t quite Heathrow

Walking the Walk

As their name suggests, pre-works walkovers aim to identify anything that a client needs to be aware of before they start work at a particular site. During the breeding bird season, walkovers cannot take place any more than 48 hours before work is due to start. This ensures no birds have the chance to build a nest on site in the interim. All nesting birds are protected from damage and destruction under the Wildlife and Countryside Act 1981 (as amended). As construction work risks causing nest destruction, any nests on site would quickly put a stop to any planned work. Outside of the breeding season when nesting attempts are unlikely, this time constraint isn’t necessary.

Fulmar egg
This late fulmar egg was a surprise find at one site

As well as checking for bird nests, ecologists also need to look for signs of any protected species on site. Our Orkney sites were all coastal. There was therefore a potential for otters to be using them in some capacity. Otter checks involve looking for spraints, couches (resting places above ground) holts (holes used for sleeping or nursing young), food debris and footprints. We also had to make sure none of the sites were being used by grey and/or common seals as haul-outs. Other locations might have the potential for a different range of species, from pine martins or dormice to great crested newts or adders.

Otter spraint
Otters tend to spraint at regular marking sites

The ecologist will also make a note of anything else the client needs to be aware of from an environmental point of view. Examples include watercourses nearby that need protecting from runoff or fragile habitats that heavy plant machinery shouldn’t be brought onto. Points to note obviously vary depending on where the site is and the scale of the works, however. The planned works on this project, for example, were going to be very small-scale and so have much less of an impact than a major construction project.

Grey seal haul-out
Coastal sites have the potential to be seal haul-outs

The Final Report

The final stage is putting all this into a report for the client. These are a clear, concise summary of anything ecologically relevant. If nothing of concern is found, this of course also needs to be stated. Reports should always contain plenty of photographs showing the site from various perspectives, along with anything that needs highlighting. On this project, this included otter spraints, seal haul-outs and watercourses near the planned works.

Papa Westray beach
Not the worst place to work!

If the ecologist identifies the potential for disturbance of a protected species, the report will highlight the need for relevant licences to be obtained before work can begin and whether any exclusion zones need to be marked out. The report will also contain recommendations for the client as to whether an ecologist should then be present during the works themselves or not. Post-walkover reports can also provide useful information about various non-ecological elements. This is especially true if the client hasn’t visited the site often or at all. Information might include access routes, parking spots and any other useful details such as the presence of livestock, aggressive dogs or electric fences.

Field gate
Information about access routes is always useful

Pre-works Walkovers

A pre-works walkover is a valuable tool for assessing the potential for environmental disturbance before planned works begin. Ecologists can highlight the presence of protected species, vulnerable habitats and anything else of note. The walkover also enables them to make recommendations to the client regarding licences and future ecological monitoring. As an added bonus, while this particular job involved some complicated planning, it helped us to tick off quite a few more islands on our Orkney list, as well!