Water protection

The water areas in Helsinki include extensive marine areas as well as the freshwater areas of the Vantaa River, various creeks, ditches, ponds and springs. In accordance with the City Strategy, the state of the small water bodies and coastal waters of Helsinki will be improved, and attention will be paid to the revival of the migratory fish stock. The significance of the sea will be strengthened and opening the nearby archipelago to public use will be continued. In addition to the environmental policy, water protection in Helsinki is regulated by the Small Water Bodies Programme, the Stormwater Management Programme, the Instructions on Prevention and Control of Floods and the Baltic Sea Action Plan.

Classification of the city’s small water bodies and mapping of the biota

Cities’ small water bodies are important habitats and migratory routes for various organisms, and they have recreational value for residents. Taking small water bodies into account in city planning and city ecology is important, as is monitoring the water quality of creeks and ponds with annual sampling.

A large area of impermeable surface in the catchment area and great fluctuations in the water flow are characteristic of creeks in Helsinki. Other challenges posed to the lotic ecosystem include occasional large amounts of solids in the creek water, hygiene problems, stream bed displacements and modifications, and a decrease in the natural vegetation of the shores. The water quality of small water bodies is affected by land use in the catchment area, the load caused by stormwater, and the soil characteristics, among other things.

In 2020, long-term work was launched to classify the small water bodies and map the biota, among other things. The objective is to identify the creeks that require special protection. In Helsinki, information is available on brown trout (Salmo trutta) populations in various city creeks, but sufficient information is not available on other valuable and threatened organisms. The objective of the work of the blue network is to produce information on the blue network’s natural values for use in land use planning and environmental monitoring and to make this information more accessible in the form of geographical information. The blue network survey contributes to the objectives of the City Strategy regarding climate change adaptation and promotion of biodiversity.

Efforts to improve the water quality of city creeks were also continued in 2020, as a large amount of deviations in water quality were detected, similarly to previous years. Because of this, project funding was sought for the ‘Tools for Improving Construction Site Water Quality’ project. The Ministry of the Environment will make the decisions on funding in 2021. The project would support the EU’s goal of having surface waters reach ‘good status’ by 2027 and the objectives of the EU Biodiversity Strategy for 2030, which is currently being prepared.

Several research projects are underway in the catchment area of the Vantaa River 

Over a million people live in the impact area of the Vantaa River, and the river winds for over 100 kilometres from Riihimäki to the bay in Vanhakaupunki. The load on the Vantaa River has decreased, and the ecological condition of the river is classified as satisfactory overall. The Kytäjoki river area and the upper reaches of the Kerava River are in ecologically good condition. Good ecological condition would also be achievable in the lower reaches if the annual median of the overall phosphorus concentration were to reach a level of 60 µg/l. Phosphorus and nitrogen enter the Vantaa River from wastewater and agriculture.

Several water protection projects are currently underway in the catchment area of the Vantaa River. The two-year RAKUVE project, which ended in 2020, studied the effects of nutrient fibre and structural lime on the erosion and nutrient loading of fields. The studies found that soil conditioners efficiently reduced erosion and washout of phosphorus, and adding soil conditioners to fields can be recommended from water protection perspectives.

The occurrence of harmful perfluorooctane sulphonate (PFOS) and PFAS-based compounds is monitored in the catchment area of the Vantaa River through the PFAS project from 2020 to 2021. Based on samples taken between 2016 and 2017, the PFAS concentrations in the Vantaa River were found to be clearly higher than in the other rivers in Finland and Sweden.

Another project launched in 2020 was a project studying the anadromous behaviour of sea trout and European whitefish. This project involves attaching radio transmitters to fish and determining how sea trout and European whitefish behave in the Vanhankaupunginkoski rapids before and after the restoration of the eastern branch. Anadromous behaviour will be monitored for three autumns.

A kayaker on the Vantaa River on a summer evening.
Picture 12. Kayaking on the Vantaa River. Photograph by Maija Astikainen.

The state of Helsinki’s marine areas is relatively stable, but harmful substances are found in the seabed and biota

The state of Helsinki’s marine areas is being monitored in accordance with an extensive joint monitoring programme. The changes in sea water quality and seabed biota have been relatively moderate in recent years. A reduced external nutrient load keeps the overall state of Helsinki’s marine areas relatively stable, and their ecological condition varies from passable to satisfactory when moving from the coast towards the open sea. The water quality and state of the aquatic environment in smaller, closed-off bay areas with a poor water turnover rate are still poor for the most part due to the nutrient and solids load carried by stormwater from built areas to the sea. In early 2020, several instances of heavy rainfall caused the wastewater system to overflow, which weakened the quality of coastal waters in places.

The sea water temperature was exceptionally high in early summer, which led to a decrease in the oxygen content of the water near the seabed in the deep basins near the coast, as well as an increase in the concentrations of soluble phosphate, indicating the vulnerability of the coastal marine areas of the Helsinki Metropolitan Area to climate change. However, the cooler and windier weather in late summer prevented extensive cyanobacteria blooms from forming in the marine areas. Nonetheless, local algae blooms occurred in Seurasaarenselkä.

The occurrence of harmful substances in the marine areas of the Helsinki Metropolitan Area was mapped more closely in 2020. Harmful substances are found in the seabed and biota, particularly in urbanised areas affected by land runoff and intensive human activity.

Wastewater was treated efficiently and instructions were prepared for the treatment of water generated by geothermal drilling

The amount of water pumped into the water supply network in 2020 was 95 million cubic metres in the Helsinki Region Environmental Services Authority’s (HSY) water supply area, while 53 million cubic metres were pumped into the Helsinki network.

The total amount of wastewater channelled to the Viikinmäki wastewater treatment plant was 110 million cubic metres, of which 79 million cubic metres originated from Helsinki. The amount of wastewater was slightly greater than the previous year. The Viikinmäki wastewater treatment plant complied with all the environmental permit regulations. Combined sewer network overflows amounted to 0.09% of the total amount of wastewater.

The removal efficiency achieved in Viikinmäki in 2020 was 97% for phosphorus, 98% for biological oxygen demand and 91% for nitrogen. The wastewater treated at the Viikinmäki treatment plant is conducted through rock tunnels to the open sea, about eight kilometres away from the shore. The phosphorus load caused by the Viikinmäki wastewater treatment plant on the marine areas in front of Helsinki was 21 tonnes (+5% from the 2019 level), and the nitrogen load was 478 tonnes (-9.8% from the 2019 level). For eutrophication, the nitrogen load is more significant because nitrogen is a minimum nutrient in the waterways in the Helsinki region.

Picture 13. The nitrogen and phosphorus load caused by the Viikinmäki wastewater treatment plant on the Baltic Sea in 2007–2020.

The environmental hazards caused to creeks from the drilling of geothermal wells have kept the environmental supervision authorities busy for several of the last few years. The challenge was met by preparing joint instructions for the treatment of water generated from geothermal drilling with HSY and the municipalities in the Helsinki Metropolitan Area. Drilling entrepreneurs were also heard during the preparation of the instructions. The instructions were published at the start of 2021.

In 2020, a water management development plan was prepared for 2021–2030. During the year, different courts issued several decisions regarding the application of the Water Services Act on applications for an exemption from the connecting obligation. Because of this, resources had to be focused on tasks pursuant to the Water Services Act, which was reflected as a decrease in other water protection monitoring. In addition to this prioritisation, the COVID-19 pandemic also contributed to the considerable decrease in the number of control inspections carried out in nature.

Speedy experiments were carried out in the Baltic Sea Challenge, and Baltic Sea Day was celebrated

Together with Turku, Helsinki is committed to implementing a third Baltic Sea Action Plan in 2019–2023. The action plan contains 117 water protection measures that take factors such as the EU Strategy for the Baltic Sea Region and the UN’s Sustainable Development Goals into account. The measures are divided between five objectives: clear coastal waters, a healthy marine habitat, clean and safe water transport, systematic use of water areas and active participation by the residents in the Baltic Sea region. The measures are divided extensively among the City divisions, in addition to which Stara, HSY and the Port of Helsinki are also involved. The implementation of the measures is monitored regularly, and 88 measures had been started, were underway or had been completed in Helsinki by the end of 2020.

The measures that have progressed include many measures related to nutrient removal, management of harmful substances, port operations and private boating, cooperation with companies and international cooperation as well as the development of the activities of the local-level Baltic Sea panel, among other things. Separate funding related to Finland’s Presidency of the Council of the European Union was used to carry out speedy experiments in the Baltic Sea Challenge. In these experiments, four companies tested new methods of preventing plastic litter and combatting plastic litter in the sea in the coastal and marine areas of Helsinki. Bloft Design Lab built a large 3D printer to turn plastic waste collected from the sea into SUP boards. Clewat Oy tested a new type of litter collecting vessel that also allows macroplastics and microplastics to be collected efficiently from challenging places. Bioharbour Ltd studied how much plastic litter is carried into the sea with food waste generated by cruise ships, while Innogreen tested the ability of a green wall to filter plastics that are generated by traffic and carried by stormwater.

In the Baltic Sea Challenge, Helsinki and Turku also support other operators in implementing new water protection and Baltic Sea activities. In 2020, five new members joined the Baltic Sea Challenge partner network and eight partners updated their commitment. In the summer, two communications campaigns were carried out for recreational boaters: the Toxin-free Baltic Sea campaign with Tukes and the Keep the Archipelago Tidy Association, and a campaign about underwater noise with students of the University of Helsinki.

On 27 August 2020, Helsinki participated in the Baltic Sea Day by holding a virtual Baltic Sea Day carnival with numerous cooperation partners, in addition to participating by other means. The carnival was streamed from the City Hall. On Baltic Sea Day, the City of Helsinki Service Centre’s catering services served fish from the Baltic Sea to all customer groups, from children in daycare to the residents of senior centres. A total of 4,500 kg of fish was used during the day.

Water protection was promoted with international cooperation

The objective of the international ‘BEST – Better Efficiency for Industrial Sewage Treatment’ project coordinated by Helsinki was to improve cooperation between industrial businesses, wastewater treatment plants and environmental authorities and develop industrial sewage processing solutions in the Baltic Sea region. The project involved Finnish, Estonian, Latvian, Polish and Russian project partners. The project lasted from October 2017 to September 2020, and its main provider of funding was the Interreg Baltic Sea Region Programme of the European Regional Development Fund.

In 2020, the project completed recommendations on the management of industrial sewage channelled to municipal wastewater treatment plants, among other things. The goal of the recommendations is to provide consistent guidelines for good practices not only throughout the Baltic Sea region but nationally to individual countries as well. In addition to the recommendations, a practical and approachable toolkit was published on the project’s investments in industrial sewage treatment and other good practices at https://bestbalticproject.eu/. 

Helsinki was also a partner in the international BSR WATER Platform project between October 2018 and December 2020. The purpose of the project was to promote cooperation between different sectors of society in water protection and, through this, influence decision-making related to water protection. The project gathers the results of various projects and best practices together in the Baltic Smart Water Hub, which is open to all. The main provider of funding for the project was the Interreg Baltic Sea Region Programme of the EU.

Eyes on the future 

The close proximity of the sea is a very important success factor for Helsinki and a part of our identity. Most of the city area is sea, and there are 300 islands in this area. The state of the marine environment must be taken into account as a source of competitiveness and well-being for the city, its residents and organisations.

Although water protection efforts have been carried out persistently and extensively in the Helsinki Group, the state of the local water bodies and the sea is concerning. Eutrophication remains the greatest issue, which is highlighted in the marine area in front of Helsinki, partly through the characteristics of the sea and its bays and partly through the load brought by the Vantaa River from its extensive catchment area. The state of small water bodies and the sea is also threatened by littering and harmful substances such as consumer chemicals, which have been studied more closely and become a topic of debate in recent years. Additionally, the significance of stormwater as a route through which many types of problematic loads enter the sea in the city area is only now becoming clear. The effects of climate change hinder the efforts to reduce loading. It is important for the parties involved in climate change mitigation, the circular economy and water protection to join forces.

Because of the COVID-19 pandemic of 2020, the significance of local nature increased. Beaches and the Helsinki archipelago also became more attractive as outdoor and recreational areas. The projects that have advanced through the Maritime Strategy have facilitated the recreational use of beaches and islands for their part. We hope that the two large maritime projects of the City that were postponed from 2020 will be implemented in 2021. In cooperation with the Finnish Environment Institute, Marine Nature 2021 will bring inventories and mapping of underwater biodiversity more broadly to the marine areas of Helsinki. The objective is to identify the underwater gems of Helsinki and support the development of the use of the archipelago, with due consideration to the sensitive maritime nature.

The maritime biennial in Vallisaari also had to be postponed. The biennial will serve as an example of how to organise a responsible event, and its aim is to be carbon-neutral. The environmental theme will be taken into account in many ways in the art to be featured at the event, with 40 visual artists drawing inspiration from the maritime environment and archipelago.