3.1. Increasing Ecological Integrity
On the Medlock, the restored site (M-Dr) had better ecological health than the unrestored downstream site (M-Du). Four out of six metrics differed significantly from zero: Richness (Mann-Whitney U = 90.00,
p < 0.001), total abundance (Mann-Whitney U = 180.00,
p < 0.001), EPT abundance (Mann-Whitney U = 72.00,
p < 0.001), and Shannon diversity (Mann-Whitney U = 144.00,
p < 0.001) were higher at the restored site (M-Dr) indicating increased diversity, abundance, and pollution tolerance (
Figure 4;
Table 2). However, the ecological health of the restored site (M-Dr) was lower than that of the upstream site (M-U), with richness (Mann-Whitney U = 1242.00,
p < 0.001), abundance (Mann-Whitney U = 324.00,
p < 0.001), EPT richness (Mann-Whitney U = 954.00,
p < 0.001), ASPT (Mann-Whitney U = 1080.00,
p < 0.001), and Shannon diversity (Mann-Whitney U = 1260.00,
p < 0.001) differing significantly from zero; all measures apart from abundance were lower at the restored site (
Figure 4;
Table 2).
On the unrestored Irk, there was some difference in ecological health between the two unrestored downstream sites (I-Du1 and I-Du2). Response ratios differed significantly from zero for richness (Mann-Whitney U = 450.00,
p = 0.022), EPT richness (Mann-Whitney U = 972.00,
p < 0.001), and Shannon diversity (Mann-Whitney U = 900.00,
p = 0.003). These metrics were all higher at I-Du1, indicating more diversity and pollution tolerant macroinvertebrates but no difference in abundance (
Figure 4;
Table 2). In contrast to the Medlock, the downstream unrestored site I-Du1 was more ecologically healthy than the upstream site (I-U), as richness (Mann-Whitney U = 288.00,
p < 0.001), EPT abundance (Mann-Whitney U = 216.00,
p < 0.001), and ASPT (Mann-Whitney U = 216.00,
p < 0.001) all differed significantly from zero, with all apart from EPT abundance being higher at the unrestored site (I-Du1) (
Figure 4;
Table 2).
Tests of seasonal differences between response ratios at each site found few significant differences so are reported in
Appendix B.
There were significant differences in response ratios between the restored (M-Dr) and upstream (M-U) sites and comparison sites (I-Du1 and I-U) on the unrestored river for richness (Mann-Whitney U = 1250.00,
p < 0.001), abundance (Mann-Whitney U = 393.00,
p = 0.005), EPT richness (Mann-Whitney U = 1084.00,
p < 0.001), EPT abundance (Mann-Whitney U = 867.00,
p = 0.017), ASPT (Mann-Whitney U = 1156.00,
p < 0.001), and Shannon diversity (Mann-Whitney U = 1163.00,
p < 0.001) (
Table 3;
Figure 5). The difference was larger between these sites for richness and abundance on the Medlock, and on the Irk for all other metrics, indicating that there is a larger difference in pollution tolerance between the upstream sites (I-Du1 and I-U) on the Irk than the restored (M-Dr) and upstream (M-U) sites on the Medlock (
Table 3;
Figure 5).
A comparison of metrics between the restored site (M-Dr) and unrestored downstream site (M-Dr), and comparison sites (I-Du1 and I-Du2) on the unrestored river showed there were significant differences between response ratios for richness (Mann-Whitney U = 231.50,
p < 0.001), total abundance (Mann-Whitney U = 318.00,
p < 0.001), EPT abundance (Mann-Whitney U = 96.00, p < 0.001), ASPT (Mann-Whitney U = 468.00,
p = 0.041), and Shannon richness (Mann-Whitney U = 147.00,
p < 0.001), although no significant difference was seen for EPT richness. Response ratios were higher on the restored river, indicating a bigger difference in ecological health between the restored (M-Dr) and unrestored (M-Du) site than the comparison sites (I-Du1 and I-Du2) on the unrestored river (
Table 3;
Figure 6).
Findings from the focus groups are summarized in
Table 4. Users of the restored and unrestored rivers both felt that the restoration of the Medlock had been successful in improving the ecological health of the river. When comparing the unrestored and restored sites on the Medlock, users of the unrestored river commented “that’s more … contrived again … (unrestored site), that’s more natural (restored site)”, whilst local users noted that the restoration “just shows how nature quickly takes over”. Local users of the restored river emphasized that the restoration had improved the variety of wildlife at the site: “All of a sudden a kingfisher was fishing there, and you could see little shoals of fish … and … these three dragonflies … all dancing over the river”.
In contrast, comments by users of the unrestored river indicated that they perceived ecological health to be equated with the neatness of the site: “I do think it (the Irk) could perhaps do with a bit of tidying up … there’s a tendency to want to let stuff grow at the sides … (which) … acts as a sort of filter for collecting rubbish”.
3.2. Benefitting and Engaging Society
All participants viewed the restoration of the Medlock as a success, with users of the restored river commenting, “that has been the biggest change, the Vale, it is lovely when you’re walking along”. Seeing the changes in the river led users of the unrestored river to reflect on the possible restoration of the Irk: “They’re doing it all up, aren’t they, with this … Big Local thing, the walkway … that’ll be nice”.
Positive views of the restoration were related to the benefits participants attributed to urban natural spaces. Users of both rivers felt that spending time in a natural environment improved their mental well-being, with a user of the restored river commenting on Clayton Vale: “I suffer from depression and I think going out here it lifts you”, whilst another user observed, “everyone feels better after you’ve been to the park”, when discussing the natural spaces around the unrestored river. Emphasis was placed on the role of the natural environment as a space to escape the urban environment. Users of the unrestored river felt that the natural spaces around the river were important in, “just getting away from it all … if we go to town, it’s all cars and whatnot, so it’s nice just to think you’ve gone away somewhere (to) be out of yourself”. Users of the restored river expressed similar views: “If you stand there and listen, you get in the center of Clayton Vale, you can’t hear any traffic, you can hear birds … it’s just a little oasis in the center of Manchester, it’s lovely”.
The importance of natural elements such as plants and wildlife in the natural spaces around the unrestored river was emphasized by users as important when they felt stress: “When I’m having a bit of a stressful day, I’ll … walk around there … listen to the birds and what have you (be) cause I think it’s all about nature”. Users of the restored river also commented on natural features in the green spaces around the restored river: “Trees and that are important because if you’ve got no trees in there what’s the point in walking down it, nothing to look at, no point in going is there?”, emphasizing their importance as focal points for visits to natural spaces.
Whilst users of both rivers described their rivers as important places for stress reduction and considered nature to play a role in this, the restoration was thought to have particularly enhanced the Medlock for this purpose. From an aesthetic point of view, the variety of natural habitats were felt to make it more interesting. When looking at pictures of the restored site, participants who were familiar with the restored river commented specifically on how at the restored site, “you’ve got a variety of colors and that … stands out”, and users of the unrestored river agreed, “it’s more varied isn’t it, I’ve got more different habitats there for finding plants”.
Water was considered important in natural spaces. Discussing pictures of natural spaces containing water, the relaxing and calming nature of watching water was emphasized by users of the unrestored river: “It’d just be calming I think, you know, you could sit and it’d be calming … to sit there and watch that”; and by users of the restored river: “Very tranquil, just the sound of the water … it’s very relaxing”.
In terms of the restoration work, users of the restored river commented that they, “don’t remember the work being done” and felt that, “they (users) were more concerned about the cycle track than they were about that (the Medlock restoration)”. Improving ecological health was important to users of both rivers and, although the Medlock restoration did not offer volunteering opportunities, contributing to other restoration work was successful in engaging local users with the restored river: “That’s one of the reasons why I joined anyway and we’re really interested in what’s on here … the wildlife and everything … it’s terribly important especially the bees”; and the unrestored river: “I quite like the river … it’s one of the reasons we turned up on the clear-up day to try and improve the river”.
3.3. Taking Account of the Past and Future
Discussions among participants indicated that, in their view, the restoration had been less successful in terms of taking the past and future into account, with comments pointing to a conflict for some between ecological restoration and the heritage of the restoration site.
Some users of both rivers felt that improving the ecological health of the space matters more than its history. Comments from users of the restored river included: “It’s part of our heritage… I’m into heritage and old buildings and things like that but some things you’ve got to change, especially for the better”. Whilst looking at pictures of the brick channel of the Medlock, users of the unrestored river discussed how built features could be undesirable despite their historical importance; regarding the Medlock, one participant said, “That looks more like a … sewer thing really”. Some users of the unrestored river also placed less value on the areas of the Irk that had poor ecological health as a result of past industry: “I’m not worried what they’re doing with that part really, I don’t know what it was before but it looks as though it’s been reclaimed”.
However, not all participants felt this way. The history of their urban natural spaces was important to some local users, on both the restored river: “That red brick is part of our history … it’s part of the history of Philips Park, it’s part of the history of Clayton”; and the unrestored river: “The industry is part of its heritage in a modern way”. These users felt that restoration should respect local history and the heritage of the area. Whilst users of the restored river commented of the unrestored section of the Medlock that, “I really would like to see something done to it as long as … it’s done properly”; they expressed the view that, “that (red brick) is also part of our history and some of it should be left”. This view was echoed by users of the unrestored river: “The industry is part of its heritage … and although we moan about it and about the quality of the water for people, I’m not sure it’s as much of an issue”.
Users of both rivers felt that familiar manmade features were either unnoticed or acceptable in natural landscapes. On the restored river, one user commented on the brick channel of the Medlock: “I suppose when you think about it, (it’s) not very natural looking, but it was something you’d always seen so you didn’t really think about it”. Users of both rivers also compared the Medlock pre-restoration to other landscapes, for example, “when you’re up there (the Pennines) … there’s this whole load of manmade stuff up there which I don’t find unpleasant”.
3.4. Sustainability
Despite the perceived improvement in ecological health, users of the restored river felt that the long-term environmental sustainability of the project was a concern. Users expressed the view that there is a general problem with the management of natural spaces in urban areas: “You come into Manchester, they’re (green spaces) badly neglected at the moment”; and were concerned that this would affect the restoration: “It was nice when I went through there (Clayton Vale) the first time … but … what it’s like now I don’t know … it’s the follow up … that’s the problem”.
Despite this, restoration was considered essential to ensuring that people continue to use natural spaces in urban areas, thus suggesting that restoration was integral to their social sustainability. Both groups felt that restoration was needed to provide access to natural spaces. Users of the restored river commented on the unrestored section of the Medlock, “it’d be nice to have it opened up, I mean at the moment it’s all fenced off”. Similarly, users of the unrestored river said, “it’s (unrestored park and river) got to be done up, they’re building more (houses) up here now, there’s going to be no green space so we’ll need it even more”.
Users of the restored and unrestored rivers agreed that, to ensure long-term social and environmental sustainability of urban natural spaces, ecological restoration is not sufficient. They emphasized the need for restorations which provide amenities and facilities so that parks appeal to people: “We need these goalposts putting back in … that will as I say attract a lot more”. These facilities were also considered essential in allowing a wide range of users to access the parks, including children: “Especially when you’re taking little ones, I think you’d really need them (toilets)”; and elderly users: “We need the community to go through there (Queen’s Park), so we need a couple of benches … the elderly can go maybe walk through with their grandchildren”.