Urban Waters and River Restoration Pinja Kasvio, Finnish Environment Institute, SYKE RESTORE North Region Closing Seminar 14.8.2013
Urban Waters Hålland, Gässlösa (Sweden) Characteristics of urban areas: people, buildings and structured areas Urban waters are strongly influenced by pollutants: Stormwater from urban landscapes, mobile sources, wastewater, industrial discharges, trash Stormwater pollutants: metals, nutrients, oils, road salt Even small decreases of green space increases stormwaters notably Tabergsån, Massadammen (Sweden) Green infra in Copenhagen
River Restoration Examples During the RESTORE project we have seen different kinds of restorations All are individual projects (catchment area, flow rate, urban density, aims etc.) Not many restored urban waters in Northern areas Lack of money Old habits to overcome Brooks in Vantaa
Example 1: River Vantaanjoki Vantaankoski, Photo by Olli Toivonen Restoration Work - in the main channel and its tributaries, since 1980s included: Sewage water treatment Dam removals Fish pass constructions Stone and gravel added Work was accomplished in cooperation with environmental authorities and volunteers Effects: improving the quality and condition of the water system Salmon and sea trout begun to migrate and reproduce Vantaanjoki Finland, Photo Pinja Kasvio
Example 2: Brook Longinoja Straightened urban brook was restored in Longinoja, Vantaa (Finland) year 2006 & 2011. Restoration work : Adding gravel and stones Creating variety to the river bed. Outcome: Beautiful scenery for the residents Brook is part of the green infrastructure Ecological channel for the animals
Trouts in Brook Longinoja Trout population density has grown Yield good trout reproduction (Saura et al 2012) After restoration 2006 and 2011 10-21 units /100 m2 2008: 25-114 units /100 m2 2012: 237 units/100 m2 Older juveniles Juveniles/100 m2 0+naturaljuveniles Saura (2013)/ RKTL RESTORATION RESTORATION
Example 3: River Isar in Münich Isar Plans Aims: 1) Flood protection 2) Enhancing Species diversity and ecological restoration 3) Improving leisure and recreation Restoration work included years 2000-2011: Restoration for 8 km Adding gravel banks, removing concrete banks, widening of river bed Planting native species, adding roots and tree trunks
Urban river Oasis as its best Birds Vegetation Effects of Restoration in urban areas 1. Sustainability 2. Biodiversity 3. Ecosystem services 4. Flood protection 5. Aesthetic delight Recreational use Flood plains Diverse, natural flow Macroinvertebrates Spawning areas
Sustainable urban management Important to manage urban water comprehensively Rely less on grey infrastructure, Use more green and blue infrastructure Improve the stormwater quality and quantity catch the pollutants as early as possible treat the stormwater add retention time, preventing flooding Use the water in urban landscape Measures: raingardens, basin, wetlands,swales, green roofs Raingarden Raingardens in Copenhagen (Denmark)
Example: Kartanonkoski, Vantaa Stormwater management in Kartanokoski sub-urban area Work included 2008: Opening the channels Creating pond, adding gravel Developing heterogenous brook Outcome: Sediment removal before River Vantaanjoki Acts as part of the green infrastructure Charming, silent place for residents Kartanonkoski Vantaa
Needs in Future Urban River Restorations Use good examples from restoration projects (RiverWiki) More co-operation with municipalities, universities, government and volunteers combine multiple aims Use green infrastructure for sustainable urban management Continue to gain understanding of urban ecological system More education, beginning from schools More research and monitoring Stormwater handling in a school yard (Copenhagen) Swales in Northamptonshire Wetlands in Copenhagen
We have multiple opportunities and possibilities to restore urban waters and get a variety of benefits
Thank you for your attention! For more information: pinja.kasvio@environment.fi