Case study: Emscher Region Structural SUDS in practice

Heiko Sieker, Stephan Bandermann, IPS, Berlin,

Michael Becker, Ulrike Raasch, Emschergenossenschaft, , Germany

The Emscher Region

• Tributary of the river in Western Germany. • Length: 84 km, Catchment area: 865 km² • Densely populated: 2.3 million inhabitants • Long tradition in steel industry and coal mining

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Subsidence caused by Mining

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

The Emscher System

865 km² catchment 40 % of the 3 WWTPs About 100 with 350 km of open catchment 1 STP Pumping have to be Stations courses drained

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Emscher Rehabilitation Project

• Ceasing of mining activities in the 1980’s subsidence stopped some year later • In 1990’s chance for rehabilitation was given • Estimated project duration ~ 30 years • Budget: ~ 4.5 Billion € • Measures a) “Decentralized” WWTP b) Combined Sewers c) CSO and retention ponds d) River rehabilitation

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

Emscher Rehabilitation Project

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Problem of Flood Peaks

m3/s 300

250 243 246 242 223

200 200 180 165 159 150 143 144 133 134 125 126 125 127 119 115 111 111 114 103108 106 107 105 92 92 92 99 101 91 92 100 85 88 89 88 84 80 81 76 75 74 69 70 71 73 71 63 68 57 49 54 50

0

1950 1960 1970 1980 1990 2000

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

"The Rainwater Route"

• Many pilot projects for USWM since the 1990’s • Subsidized by Emschergenossenschaft and the Ministry of Environment of the Federal State

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future "The Rainwater Route"

SWITCH Pilot Training Johannesburg May 2010 : Fotos: M. Kaiser Managing Stormwater in the City of the Future

Stormwater Management Information System (SMIS) • Pilot projects are good for demonstration... • ...but effect on catchment level is small • Catchment-wide investigation

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Potentials for Disconnection

Legende Abkopplungspotenzial bis 5 % 5 - 20 % 20 - 40 % 40 - 60 % 60 - 80 % 80 - 100 %

Average Potential: ~ 18%

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

Infiltration  Groundwater

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Infiltration  Groundwater

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

Project "15/15"

• Target 15% disconnection in 15 years • Contract between a) Emschergenossenschaft b) Federal State Ministry c) 17 municipalities • “Storm Water Convention” was signed in Oct. 2005

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Actual situation • Although a) Many successful pilot projects b) BMP/SUDs are common practice for new developments c) Potentials for catchment-wide application are given d) From technical point of view decentralized urban stormwater management systems are ready to use e) Political support • Still a) Resistance e.g. from drainage departments b) Hard to switch the daily practice

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

Emscher and SWITCH • Emscher region is a demonstration “city” • What they can bring in a) Demonstration projects b) Ongoing projects c) Experience with design, o&m, cost effectiveness, … • What they expect a) Overcome the resistance b) Help for “switching” daily practice c) E.g. Life-Cycle-Cost-Assessment tool

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Life-Cycle-Cost-Assessment

• See CD-COM • For more information www.sieker.de

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

Demonstration Projects

• Welheimer Mark: Disconnection of roof areas • Lake Phoenix: Integration of open water systems into urban space • Klöcknersiedlung in Disconnection of roads by using "pocket wetlands" • Drainage-Infiltration-System Herne Combined management of stormwater and groundwater

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Disconnection in Essen

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

Disconnection in Essen

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future Welheimer Mark

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future

Thank you for your attention

SWITCH Pilot Training Johannesburg May 2010 : Managing Stormwater in the City of the Future