Reconstruction of the Lepiku channel in Tallinn's Botanic Garden, Estonia

National Id
Estonia_03
Site name
Lepiku channel
Summary
Reconstruction of the Lepiku channel that is a part of the drainage system, which starts from the new residential area next to the Tallinn Botanic Garden and includes wetlands, detention ponds, ditches and channels and debouches into Pirita river. The aim was to improve the quality of the storm water that flows into the Pirita river. The river Pirita is a part of Natura 2000 site and flows into the Baltic Sea. The length of the reconstructed channel part is ca 195 m and the works included: widening of channel bottom in different segments, creating artificial dykes and rapids and creating suitable conditions to the aquatic plants exhibits in Botanic Garden.
NUTS Code
Eesti
RBD code
EE1
Transboundary
0
NWRM(s) implemented in the case study
Longitude
24.8764
Latitude
59.4822
Climate zone
cool temperate moist
Mean rainfall
450
Mean rainfall unit
mm/year
Type
Actual Test Site
Light or indepth?
Light
Vegetation class
Botanic garden area where near the channel are different plants
Monitoring parameters
Monitored will be in future water quality (N, P etc)
Performance impact estimation method
Catchment outlet
Application scale
Plot
Installation date
2015
Performance timescale
1 - 4 years
Area (ha)
150.4
Size
195
Size unit
m
Favourable preconditions
The aim for Tallinn Botancal Garden was reorganisation of the channel section. And not just cleaning the channel and ensuring banks but while doing it to keep in mind water purification, water regime regulation and aesthetic appearance. Aim was to design a modern, eco-friendly and not very costly solution, which would set a good example for the other channels and trenches in Tallinn. Maybe to change the the way of thinking to solve the problem through hiding water into the pipe underground instead bringing it visuable in the channel on the ground
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Design consultation activity
Activity stage Key issues Name Comments
Design land use change
Land use change type
Design authority
Authority type Role Responsibility Name Comments
Other
Initiation of the measure
1. Tallinn Environment Department
Tallinn city Environment department
Other
2. Tallinn University
Carried out a survey in coastal parishes (in Baltic countries) with the aim to find out the attitude of people towards environmental protection measures and their practice
Implementation
3. Construction company
Construction works ordered by Tallinn Environment Department
Other
4. Tallinn Botanic Garden
Getting reconstructed channel in their territory
Other
5. Citizens of Tallinn
Getting new information
Determination of design details of the measure
6. 4People OÜ
Innovative approach, all design was made by Gen Mandre from 4people OÜ (www.4people.ee). He is also involved in the project “(D)rain for Life” which is concentrated on Sustainable Urban Drainage Systems (SUDS) - http://drainforlife.eu/index.php/en/).
Key lessons
Not available yet
Financing mechanism information
Project was financed by LIFE+, Minitry of the Environment of Finland and City of Tallinn
financing funding solutions
Usaually LIFE+ cofinancing is 50% but in agreement the share was raised based on the co-financing of Finnish MoE to 84,91% which left to City of Tallinn co-financing share of 15,09 %
Success factor(s)
Success factor type Success factor role Comments
Financing possibilities
main factor

measeure was implemented in frame of the LIFE+ project “Benchmarking water protection in cities – CITYWATER” (LIFE 11 ENV/FI/000909)

Legal obligations
secondary factor

Achieving good ecological quality of waters by 2015 (WFD)

Other
main factor

The success of the project can be evaluated on two levels. The first is the population, land owners and the government's awareness. The project has justified itself when in the Lepiku channel upper course rainwater is handled by using local solutions rather than just leading the water into a sewerage. The second positive aspect of the project is the quality of water that runs from the Lepingu water course into Pirita river. It is assumed that in the reconstructed area of the ditch, the self-cleaning system is quite effective. However, to prove this, it will be necessary to monitor the area. Monitoring will commence right after the ending of reconstruction.

Financing
Financing type Comments
EU-funds: LIFE+
LIFE+ project “Benchmarking water protection in cities – CITYWATER” (LIFE 11 ENV/FI/000909)
Local funds
Cofinancing by City of Tallinn
Other
Cofinancing by Ministry of the Environment of Finland
Barrier
Barrier type Barrier role Comments
Other
main barrier
1. The biggest drawback was caused by weather. Because of the long and heavy raining period, movement for mechanisms was hindered; on both sides of the watercourse different collections of trees were planted and the area for mechanisms to move was quite narrow.
2. One more drawback was with electrical cable, which was mentioned in the project, but the location (depth) was different. The problem was solved by adding one extra culvert under the cable and rebuilding one small section to ensure the right slope.
3. Soil erosion, which was caused by heavy rain again, was solved by placing natural grass carpet instead of waiting grass to grow from seeds.
Driver
Driver type Driver role Comments
Legal obligations
main driver
Achieving good ecological quality of waters by 2015 (WFD)
Other
main driver
Availability of funds - measeure was implemented in frame of the LIFE+ project “Benchmarking water protection in cities – CITYWATER” (LIFE 11 ENV/FI/000909)
Financing share
Financing share type Share Comments
European funds
84.91
LIFE + and Finnish MoE together - 84,91 %
National funds
15.09
Tallinn City - 15,09 %
Policy description
There are in total 9 ponds in the territory of Tallinn Botanic Garden, some of them feed on springs and the water collected in the Botanic Garden´s territory but most of the water is coming from Lepiku channel (catchment 150,4 ha). Most of the ponds were built in 1963-1965 on channels that existed before. The Lepiku channel that is feeding the ponds of Botanic Garden has not been cleaned for years. Additionally the channel is partly closed to pipes which hinder water runoff and self-cleaning of water. The ponds have been cleaned and the banks been fixed depending on financial possibilities.
In last ten years it was noticed that in the years that were warmer and had less precipitation the water started to “bloom” – satiated with different algae and aquatic plants were proliferating which refers to nitrogen and phosphorus compounds’ inflow from Lepiku channel catchment where a lot of new buildings have been built. It is also possible that the bottom of one pond is polluted by fuel oil that that was flowing in there from a boiler house that was situated in the bank of the pond in 1980s.
That meant that excessive amount of suspended solids, nitrogen and phosphorus compounds and possibly oil products end up in the gulf of Finland that is 2,5 km away via Pirita river.
Part of wider plan
1
Policy target
Target purpose
Pollutants Removal
Policy pressure
Pressure directive Relevant pressure
Policy area
Policy area type Policy area focus Name Comments
Policy impact
Impact directive Relevant impact
Policy wider plan
Wider plan type Wider plan focus Name Comments
Local
Water
Development plan of Tallinn 2009-2027
5th main objective: citizen of Tallinn connecting sustainably home, work and rest – Tallinn with cosy, inspiring and environmentally sustainable urban space,
5.4 Technical infrastructure services are of high quality, available for residents of the city and meet the safety and environmental protection requirements
Measure 2: guaranteeing channelling of storm and surface water
Link to the document: https://www.tallinn.ee/eng/g3230s54397
Local
Water
Tallinn Environmental Strategy 2030
Point 2.3.1.3.(Coastal waters) states that the aim is to restore the ecological balance in marine environment and guaranteediversity of nature and achieve in necessary water quality in the recreational areas.
Point 2.3.2 (rain water) emphasizes the need to work out concept for rain/storm water removal.
Link to the document: http://issuu.com/tallinna_keskkonnaamet/docs/strateegia_ingl/3?e=0
Local
Water
Tallinn public water supply and sewerage development plan 2010-2021
Point 10 (storm water systems) maps the bottlenecks related to storm water removal, including the degrading impact of water flowing in from the urban region to the status of Tallinn Botanic Garden ponds both in quantitative and qualitative way, which in turn degrades the quality of storm water flowing in Pirita river
Local
Water
Tallinn stormwater strategy to 2030
Point 3.2.11 (new catchments) foresees the development of Lepiku-Laiaküla catchment as the area needs researches and development of holistic solution in order to guarantee storm water removal and good status of Tallinn Botanic Garden ponds.
Point 6.1 sets the strategic aim to achieve ecological status of storm water recipients (coastal sea and inland water bodies of Tallinn) and continuous improving of the storm water quality that flows in the recipient water bodies.
Policy requirement directive
Requirement directive Specification
Direct benefits information
Reconstruction and cleaning of the Lepiku channel means that cleaner water will flow in to the Botanic Garden’ s ponds and later in Pirita river and in the Gulf of Finland – this way improving the ecological status of water.
Ancillary benefits information
The reconstruction of the Lepiku channel on the territory of Tallinn Botanic Garden may be handled as a pilot project, the objective of which is to raise awareness of the residents of the area. In the lower course of the reconstructed ditch the self-cleaning system should be more effective than in the straight, piped upper course, as is the case at the moment in the upper course. The innovation, by most part, lies in the fact that with very simple means and relatively low cost it is possible to build a self-cleaning, aesthetically enjoyable rainwater handling solution. The solution will help the residents of the drainage area to understand the need the importance of water conservation and offers inspiration to land owners whose land the ditch passes through, and hopefully helps them to understand that an attractively and effectively built ditch will increase the value of their land, rather than be a possible area for problems.
Costs investment
35000
Costs investment information
reconstruction works including materials and designn
Information on Ecosystem improved biodiversity
No information
Information on Ecosystem provisioning services
No information
Ecosystem impact climate regulation
No information available
Information on Water quality overall improvements
In last ten years it was noticed that in the years that were warmer and had less precipitation the water started to “bloom” – satiated with different algae and aquatic plants were proliferating which refers to nitrogen and phosphorus inflow from Lepiku channel catchment where a lot of new buildings have been built. It is also possible that the bottom of one pond is polluted by fuel oil that that was flowing in there from a boiler house that was situated in the bank of the pond in 1980s.
That meant that excessive amount of suspended solids, nitrogen and phosphorus compounds and possibly oil products end up in the gulf of Finland that is 2,5 km away via Pirita river. Reconstruction and cleaning of the Lepiku channel means that cleaner water will flow in to the Botanic Garden’ s ponds and later in Pirita river and in the Gulf of Finland – this way improving the ecological status of water. As works are not yet finalised then chane cannot be estimated.

Partners

Logos of all partners of NWRM project