Impact on Environmental Services

The impact of the Oxford Flood Alleviation Scheme on the benefits we get from nature

Dr Riki Therivel, sustainability consultant and visiting professor at Oxford Brookes University has examined the impact of the Oxford Flood Alleviation Scheme on environmental services. Her research has backed up fears of biodiversity loss and she forecasts massive potential loss of ecosystem services with carbon costs potentially “off the scale.” Dr Therivel said that by her calculations, just the costs of loss of amenity during construction will completely outweigh any net environmental benefit from the scheme, suggesting the figures have been “massaged” by the EA. 
“A flood alleviation scheme is definitely needed. But the proposed OFAS scheme will have  ecosystem services costs which have not been fully considered by the EA. Other schemes not considered by the EA may deliver the same benefits with fewer costs. For example, smaller, incremental actions that can be monitored and managed.”

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I'm one of the local residents who walks their dog on Hinksey Meadow twice a day.  When the Environment Agency came out with the flood alleviation scheme, I was broadly in favour of the idea.  But the thing that I care about most is whether I can walk my dogs and look at this extraordinarily beautiful meadow, so I wanted to know how well the Environment Agency has taken my views, my concerns into account.  Through a Freedom of Information request I got hold of the Environment Agency’s benefit-cost analysis, and in there one paragraph is about their ecosystem services analysis.  I thought that would cover my concerns about the recreational use of the meadow and wider field system, especially during the 3-to-5-year construction period.

I got hold of the ecosystem services report through another Freedom of Information request.  For those of you who don't know what ecosystem services are, it's basically the benefits that we get from nature – for instance tranquillity, recreation, carbon fixing, food provision and the like – which are often difficult to monetize, to put into pound signs. For instance, for flood protection, an ecosystem services analysis might identify the number of homes affected by flooding and multiply that by the cost incurred if those homes are flooded.  With recreation, the analysis might use ‘willingness to pay’, for instance how many people use the field system and how much they would be willing to pay to use those fields if there was a gatekeeper taking in money.  

You yourself might think about the benefits that you get from the OFAS field system, and whether they would be affected positively or negatively through first the construction and then the operation of the proposed flood alleviation scheme.  That would be the logical, ‘person in the street’ approach to ecosystem services analysis.  Now, for me, it would be recreation because of the dogs. And I would think, well, during construction, the scheme’s impact on recreation will be clearly negative, because I wouldn't be able to walk there, and afterwards there will probably be more limited space in which to walk. And maybe carbon fixing and biodiversity.  I'm sure you'll have your own views. 

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Environment Agency's Analysis

Now I will show you the Environment Agency's analysis of the ecosystem services benefits and costs of the proposed scheme.  The orange lines are the operation costs and benefits, and the blue non-existent lines are the construction costs and benefits.  Heading to the right are benefits, and if they headed to the left they would be costs.  

You can see from this figure that the biggest benefit is for anglers during the operation of the scheme, because the scheme is going to maintain the existing fishery. I don't know about you, but to me, it doesn't sound like a positive, it sounds like a like a zero.  The Environment Agency suggests that walking and cycling would be the same with and without the OFAS scheme, which I think is probably about right.  They say that there would be benefits to supporting services, those are the biodiversity dimensions that Dr. King mentioned.  They are basically saying that, because they are going to be replanting trees and having more variety of habitats, there will be benefits.  They also say that if the scheme’s assumptions in terms of water levels are not met, it could have severe adverse environmental effects, but they don't monetize those. And they say that the climate change impacts of construction will be modelled separately, but my freedom of information requests for that has not come back yet.  Basically the Environment Agency is saying that the scheme will only have benefits and no costs.

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Dr Therivel's Analysis of the Cost

And then I thought, what would I say? So, I added the blue lines to represent impacts during construction. Starting from the top, the impact on tranquillity and aesthetics would definitely be negative during construction, particularly in South Hinksey with lorries rumbling by for three to five years.  During construction, walking and cycling would be a clear negative because we would be very restricted in where we can go during that time.  Using the Environment Agency’s own assumptions, if people were willing to pay £2.50 per visit; and using only the 2011 assumptions in terms of numbers of people (which has obviously become much higher with Oxford’s increased population and coronavirus); over just three or four years those costs would completely outweigh all of the the ecosystem services benefits that the Environment Agency says there will be.  In terms of carbon sequestration, I have no idea what number they're going to put on it, but I’m guessing that the blue line would go down to somewhere near Frideswide Square.

I’d argue that supporting services would be negatively affected during construction because of the 1000s of trees felled and the loss of 2 hectares of MG4 meadow. During operation, I think that biodiversity would also be negatively affected for many years.  So, what you'll see is that my calculation, is very, very different from the Environment Agency’s.

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Dr Therivel - "we need to consider the true costs."

Now, all of this is small beer.  The Environment Agency are talking about £1.6 million of ecosystem services benefits, and I might be talking about £10 million of costs. But the costs of the scheme are about £150 million and the purported benefits are ten times that, so the difference between £1.6 million benefits and £10 million costs is comparatively small.

But it's actually not. Because what all of this suggests to me is that the things I care about are not being considered adequately, that they're being kind of massaged to make the scheme look good. I think that a flood alleviation scheme is needed. But I think that the proposed scheme will have definite costs which have not been adequately considered, and which need to be considered. And I think that other schemes could have better ecosystem service benefits, fewer ecosystem service costs, and no greater cost overall for the scheme. For instance, I think can the Environment Agency could consider having what I would call ‘monitor and manage’: implement a series of smaller schemes, monitor whether they work, and then add more if necessary.