Information

Information

Experiences from the CITYWATER project

Renewal of current stormwater management is a timely topic in the Baltic region, as several cities strive to move from pipe solutions to sustainable stormwater management. Many cities also feel the need for better coordination of stormwater issues and are striving for comprehensive or integrated stormwater management within their city organisations. In Finland too, changes were recently made to the relevant legislation, giving municipalities overall responsibility for arranging stormwater management within cities. However, general information and experience of alternative management solutions are scarce – examples of best practices are needed in support of decision-making, implementation and resource allocation.

Read more about storm water and sustainable storm water management here.

Examples

Examples

In the map below, you can find examples of water protection measures within this topic. These actions are picked from the Bank of Actions – if you are interested to browse for other water protection actions, visit the Bank of Actions.

	Plans for Häppilännotko wetland City of Turku
	Reconstruction of Lepiku water course Tallinn City
	Sustainable storm water management through biofiltration City of Helsinki

Agriculture

Awareness raising

Hazardous materials

Littering etc.

Oil spill prevention

Research and monitoring

Shipping and boating

Stormwater management

Strategies and programs

Wastewater management

Other

Drainage basin

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Sustainable storm water management through biofiltration

Actor: City of Helsinki   ●   Year: 2015   ●   Address: Metsäläntie 2, Helsinki, Finland

A sustainable storm water management solution based on biofiltration was realised in Maunulanpuisto Park in Helsinki, in order to purify rainwater and meltwater and improve water quality in the Haaganpuro Brook.

Description

Rainwater and meltwater collected in drains from a lively trafficked drainage area are channelled to a sedimentation basin, in which a large part of the solids sinks to the bottom. The water then continues its journey to the biofiltration area where it is allowed to pool, giving vegetation time to bind nutrients and heavy metals. After this, the water slowly permeates the filtrating sandy layers under the vegetation, during which harmful substances are absorbed by microbiological activity. Finally, the purified water is fed into the ditch via a drainpipe and onwards into the Haaganpuro brook.

Benefits

As the drainage area is heavily trafficked and paved with asphalt, high solid, nutrient and oil levels have occasionally been measured in the rainwater and meltwater entering the Haaganpuro brook. Such contamination is harmful to the fish stocks (e.g. trout) and other organisms in the brook. The biofiltration solution is the first of its kind in Helsinki. In connection to the solution, an info board describing the objectives and functionality of the solution as well as the general challenges that cities face regarding storm waters and their management (increasing rainfall and condensed urban structures) was erected in order to inform local residents on the issue.

Background information

The sustainable storm water solution was implemented within the EU LIFE+ financed CITYWATER- Benchmarking water protection in cities project. The objective of the project (2012-2015) was to facilitate and implement ambitious water protection measures. The solution also supports the City of Helsinki storm water strategy, which aims at changing management towards sustainable solutions and states that storm water should in first hand be infiltrated on spot, where it is created.

Further information

Name: Kajsa Rosqvist   ●  Email: kajsa.rosqvist (a) hel.fi   ●  Web page: www.hel.fi

Guidelines & Recommendations

 Guidelines & Recommendations

Working with stormwater issues in practice means implementing physical changes in the urban space. Such work therefore involves a range of stakeholders such as city departments, citizens and companies. In most cases, it also requires a range of permits and background reports, coupled with careful financial planning. Intensive cooperation among all stakeholders and the careful prediction of all potentially time and money-consuming aspects are required for the successful implementation of sustainable stormwater solutions.

Implementing a sustainable storm water solution

Working with stormwater issues in practice means implementing physical changes in the urban space. Such work therefore involves a range of stakeholders such as city departments, citizens and companies. In most cases, it also requires a range of permits and background reports, coupled with careful financial planning. Intensive cooperation among all stakeholders and the careful prediction of all potentially time and money-consuming aspects are required for the successful implementation of sustainable stormwater solutions.

1. Planning (1-2 years)

Setting aims

In an ideal world, there would be enough time to plan forthcoming projects properly, with project plans being drawn up on the basis of realistic feasibility studies before actual project planning begins. However, in the real world, planning is unfortunately often based on assumptions. With respect to EU-financed projects on sustainable stormwater management solutions, the ideal approach would be to decide on the location and solution to be built when applying for financing, in order to ensure realistic budget estimates. In addition, during this phase it is important to set clear aims for the work, since these will support and guide planning and implementation in all phases.

• Set aims and requirements for the solution. These may involve solving problems related to quality standards (e.g. environmental impact), quantity requirements (amount of water to be managed), methodological testing (e.g. evaluation of different solutions) or a combination of these and several other factors
• Choose the location and type of solution, if possible

Headhunting of key persons to commit to the project – City internal working group

As stormwater issues usually involve the areas of responsibility of several city departments, a key step in ensuring the realisation of a stormwater solution would be to involve key persons from different city sectors and departments in ensuring that all relevant issues are considered and disseminated. At the preparation stage of planning, the actor should contact these persons in order to secure their commitment to the project. It would also be important to acquire knowledge and experience related to the feasibility of various plans (preliminary insights on general needs, permits, city planning processes related to time-scale, environmental impact analyses etc.)

A city internal group should be formed when planning is begun, at the latest (i.e. if EU-funded, the support has been acknowledged). Such a group could support the project work and gather or at least provide channels for the information and experience required on the realisation of the solution. People are motivated and committed when given clear tasks. This would also provide a structure for the work and signal that the related commitments have been clearly defined. The roles of various group members should be clearly defined to ensure that everyone is aware of what is expected of them. As representatives of their departments, during the planning phase such persons should consider what issues may need to be solved or might present obstacles to the realisation of the plans!

• Look for interest among key persons representing different city sectors or departments (environment, construction, planning, possible researchers from the University etc.).
• Set clear tasks and aims for the group and a time limit for the work

Considering of needed permits, statements and assessments

Is there a prerequisite for specific statements from any authority, related to the chosen location or solution? Do you need approval from e.g. the Environmental or Public Works Board? Which department within the city administers the land, what kinds of negotiations or permits are required prior to construction? At what stage of completion is the master or city plan for this area? Are there restrictions based on these and other plans? Are some environmental impact assessments lacking or do some recognisable environmental impacts need to be taken into account? These are some of the questions that might arise.

• Assess the potential official approvals needed. The sooner all possible restrictions are considered, the better. The city internal group would be of help in this.

Budgeting

During construction projects, budget planning is never easy and the funds required are commonly underestimated. Feasibility studies are recommended in every case. Unfortunately, due to time constraints these are seldom realistic. Ask the key persons for help with this!

Remember to budget at least for the following:

• planning (consultants) (usually 10-20 % of the total costs)
• provision of background information such as geological information (possible substrate drilling and sediment analyses)
• technical details (pipes, electricity lines etc.)
• environmental impact analyses (water samples etc.)
• possible adjustments to the plans (consulting company)
• dissemination of information (residential meetings etc.)
• construction

Choosing a consulting company for defining the solution and construction plans

Directly after the kick-off for the project, it is important to begin planning the solution quickly, by drawing up a construction plan and preparing the required additional documents. We recommend that you use consultants for construction planning. Since this usually requires what may be a time-consuming tendering process, it is wise to start early.

It is usually easier to choose a suitable stormwater management solution in cooperation with consultants than have public servants decide on the matter alone. Background information on the location, including geological information (substrate drilling etc.) and technical details (pipes and electricity lines etc.) is required when choosing a solution. Such information should be provided by the public servants, which means that the city internal working group also plays a crucial role in this matter.

Construction planning should also be handled on the basis of cooperation between you, the consultants and the city internal working group, with regular meetings being held as planning proceeds.

• Choose the consultants to be used. Reserve time for the tendering process.
• Reserve enough time for meeting with the public servants and checking the construction plans alongside the various departments involved! Take note of the possible approval processes and permits mentioned above.

Informing local residents

When drawing up the construction plans, you should present them to local residents in order to obtain feedback and prepare all stakeholders for the construction phase.

• Organise local briefing events for residents. Use the social media and newspapers to spread information.

A general remark

In most cases, a city centre is the most complex site for new stormwater management solutions, mainly due to lack of space and existing structures. It may be considerably easier to implement stormwater solutions in the outskirts of a town or in new areas. City centre locations also tend to require the involvement of more stakeholders and higher costs. However, usally the risks and problems related to stormwater issues are more severe in the city center than elsewhere, making urgent action necessary.

Discussing among civil servants and local residents regarding urban stormwater planning and implementation is a crucial part of sustainable management (Photos Eliisa Punttila)

 2. Construction (1/2-1 year)

The construction may be handled by a private or municipality owned company. It is, however, important to make sure that the process and especially safety aspects at the construction site are carefully observed either using expertise within the city or using an external consultant.

Basic construction plans and pictures:

• Principal plan
• Construction plan
• Cross section picture
• Longitudinal section pictures
• Water service plans
• Map with soil and sediment and well information
• Picture of bottom structure details for the construction
• Other?

Additional documents in support for the construction plans:

• Cost estimates for the entire construction and possible bigger separate phases
• Management plan for usage and maintenance
• Quantity lists
• Safety document
• Work description
• Other?

During construction it is important to have regular meetings at the site to observe the process and make possible corrections if needed. The construction process ends with a meeting to set the final official approval of the construction. Use the city internal group also during this phase.

3. Maintenance

It is wise to ask the planning consultant to prepare a maintenance plan for the solution already in the planning phase. Furthermore, it should be decided which department in the city is responsible for maintenance of the site, e.g. the Public Works Department. Concerning environmental quality assessments, the Environmental Department is usually a natural actor. The maintenance plan should list activities to be done with a clear time schedule, e.g. check functionality on a regular basis, at a minimum twice a year etc.

Construction and supervision (Photos Kajsa Rosqvist)

Extras

Extras

Below, you will find further information, useful reading and useful links on this topic.

Urban rain – wasted in rain. Sustainable storm water solutions for greener cities. Brochure describing the sustainable solutions planned and constructed within the CITYWATER Project. Link_to_the_brochure.

Blue-green Fingerprints of Malmö
A book describing Malmö’s transition from a traditional urban drainage via buried pipes towards a sustainable urban drainage in open systems
Link to the book

Handbook on sustainable urban drainage systems
(D)rain project report
Link to the handbook

Fifth Dimension – Green Roofs in Urban Areas
LUOMUS, Finnish Museum of Natural History webpage on the University of Helsinki research group for sustainable green roofs.
Link to the report

Climate-Proof City – The Planner’s Workbook project web page
Link to the web page

Valtanen, M. Effects of urbanization on seasonal runoff generation and pollutant transport under cold climate. University of Helsinki.
PhD thesis on storm water quality.
Link to the thesis