Urban Stream Restoration - Cost Effective?

In Ellensburg, over the last century, many miles of streams have been piped and wetlands have been filled. Most of the remaining streams and wetlands are degraded to some extent through physical and hydrologic alterations, invasive species, and pollutants. Many Ellensburgians have limited access to, and interactions with, streams and wetlands.

Urban streams and wetland restoration projects can help create access and provide other social and environmental benefits by transforming the urban landscape. But these projects need to have clearly defined goals, be tied to integrated community and watershed plans in some way, and be maintained. The concept of stream daylighting offers an example of the benefits, and challenges, of one type of ecological restoration that might be easy to convey to the public and decision makers. See below for an article related to urban stream daylighting and join KEEN on October 22nd to learn what efforts are happening locally.

Making the Case for Urban Stream Daylighting

Recently, Gilbert Rochecouste, a placemaker, proposed that Williams Creek, channelled in a stormwater drain under Elizabeth Street in the centre of the city of Melbourne, Victoria, Australia, should be daylighted. The proposal was described as “unfeasible” by the city council. How can we advance the cause of daylighting and restoration of urban streams, ponds and wetlands? One way is to demonstrate their benefits and evaluate them in monetary terms. We need to develop the business case. The benefits are often expressed as economic, environmental and social. Laura Musacchio, an American landscape architect, suggests that we should broaden this triple bottom line to 6 E’s for sustainable landscape design: economic, environmental, equity, (a)esthetic, ethical and experiential.

Let’s look at what is known about these benefits. If we know what they are, we can more easily put a dollar value on them, for those interested in the business case.

For the moment, let’s put aside the economic benefits, with the assumption that they will be evaluated. Some of these benefits have markets, e.g. fishing, and can be evaluated easily. Some non-market economic benefits, e.g. ecotourism, can also be evaluated with methods such as ‘willingness to pay’. It’s the evaluation, in dollar terms, of other non-market benefits that’s tricky. Many of those benefits derive from the other Es. Let’s consider them.

Environmental benefits must be self-evident, surely: increased biodiversity, improved water quality, reduced urban flooding, aquifer recharge, improved urban microclimate, etc, etc. Some of these can be evaluated economically, e.g. value of insurance claims prevented by restoration of wetlands to reduce urban flooding. Some cannot, e.g. intrinsic value of biodiversity.

Benefits involving equity, aesthetics, ethics and experience of waterways and wetlands generally do not have markets to inform their evaluation. Nevertheless, these benefits are increasingly acknowledged and the subject of research in many countries. Much of this research is based around the theme of well-being and has shown the critical importance of urban nature, accessible at creeks and rivers, ponds and wetlands, to human well-being, contributing to psychological restoration and improving health. Some of these benefits derive from experiencing the landscape. Other benefits result from the improved thermal comfort of the urban landscape as a result of the vegetation and water within it. The presence of water also provides benefits associated with opportunities for passive and active recreation.

The aesthetics of the waterway or wetland are important in perception of the benefits. Not everyone uses the same aesthetic when they look at the world. There are at least four ways of looking at landscapes, discussed by Paul Gobster, Joan Nassauer, Terry Daniel and Gary Fry, in their very interesting paper titled “The shared landscape: what does aesthetics have to with ecology?” (Landscape Ecology, 2007, 22, 959-972). People using a scenic aesthetic look for beauty in the landscape, whereas those using an ecological aesthetic look for dynamism, ecological function and health. A tension exists between these two aesthetics, for both can interpret the landscape as ‘natural’. In scenic landscapes, perceived naturalness might not reflect the scientific notion of naturalness, which is valued by the ecological aesthetic. An aesthetic of care and effect of knowledge values signs of human care and intent in the landscape, and an aesthetic of attachment and identity values cultural landscapes that reflect place attachment and identity.

Which of these aesthetics, then, might be used when looking at restored waterways and wetlands? How might the different aesthetics influence their perception and value? I would suggest that waterways and wetlands can be viewed favourably with any of these aesthetics, so that they are appreciated and valued. Context of the waterway or wetland in the landscape is all important, as are the personal characteristics of the viewer, including knowledge and familiarity. However, the scenic aesthetic and the aesthetic of care and effect of knowledge might not always yield favourable perceptions. Not all creeks, rivers and wetlands are beautiful and many can look messy and uncared for, particularly in an urban context. This potential pitfall, though, can be overcome with attention to the design and maintenance of the restored landscape, to suggest that any apparent ‘messiness’ is intended, and by promoting familiarity and understanding of these landscapes.

So we return to the pesky problem of providing a business case for the daylighting and restoration of urban streams, ponds and wetlands. We must look to the economists to evaluate in dollar terms the myriad non-market values of the benefits of these waterbodies. I know that they are working on this, for example within the Cooperative Research Centre for Water Sensitive Cities, based in Melbourne, Victoria, Australia.

In addition, we must encourage everyone to discuss this issue, so it is already part of the public discourse when we have the business case to make it a priority in urban planning. Meredith Dobbie http://www.thenatureofcities.com/