Water Status Monitoring
Monitoring of Water Bodies and Groundwater Status
Monitoring of Water Body Status
In the Hämeenlinna and Hattula area, water status is monitored annually through water sampling conducted by the City of Hämeenlinna and the Regional State Administrative Agency (until 31 December 2025, the Centre for Economic Development, Transport and the Environment of Häme). Other parties monitoring water quality and water status include, for example, water protection associations and research institutions (e.g. the Lammi Biological Station of the University of Helsinki).
The environmental protection authority of Hämeenlinna follows an annual environmental status monitoring programme in the monitoring of water body status, and the monitoring results are published on the city’s website. The results have also been stored in the environmental information management system Hertta’s water quality section.
Monitoring of Water Body Status 2025
In 2025, the City of Hämeenlinna studied the status of surface waters with water samples taken in early September from seven lakes. Lakes of different sizes were selected for monitoring where several years had passed since the previous monitoring or where recreational use is significant.
The monitored lakes were
- Keihäsjärvi (Kalvola)
- Pyyttämö (Renko)
- Velkoja (Hämeenlinna)
- Vuolijärvi (Hauho)
- Vanajavesi Lusinselkä (Hattula)
- Iso Humalajärvi (Tuulos)
- Tevänti (Lammi)
Phytoplankton was also studied from Keihäsjärvi. The results of the water samples are available in the surface water section of the environmental information management system Hertta, and a summary of the results has been compiled in the report below.
Monitoring of Water Body Status 2024
In 2024, the City of Hämeenlinna studied the status of surface waters with water samples taken in August from eight lakes, and in addition one ditch water sample was taken.
The 2024 monitoring included
- Iso-Salanti (Kalvola)
- Rietajärvi (Renko)
- Aulangonjärvi (Hämeenlinna)
- Akkijärvi (Hauho)
- Ylinen Savijärvi (Hattula)
- Kastanajärvi (Tuulos)
- Alanne (Lammi)
- Iso-Roine, Sappeenjärvi (Hauho)
A ditch water sample was taken from the Iso-Talvilahti ditch flowing into Iso-Roine. A phytoplankton sample was taken from Rietajärvi, for which there is a separate report. The results of the water samples are available in the surface water section of the environmental information management system Hertta, and a summary of the results has been compiled in the report below.
In autumn 2024, the Lehijärvi catchment area loading survey was completed, commissioned in cooperation with HS-Vesi, the City of Hämeenlinna and the Municipality of Hattula. The objective of the water quality and flow studies conducted in 2023–2024 was to investigate the water quality of ditches flowing into Lehijärvi and the loading from different parts of the catchment area.
Monitoring of Water Body Status 2023
Water body monitoring was carried out in 2023 on seven lakes, from which water samples were taken in August 2024. The results were compared with monitoring results from previous years, and each lake was assigned a usability class from the perspective of recreational use.
The 2023 monitored lakes were
- Saunalammi (Lammi)
- Pyhäjärvi (Hauho/Tuulos)
- Armijärvi (Hattula)
- Kirkkojärvi (Renko)
- Matkolammi (Hämeenlinna)
- Emälammi (Kalvola)
- Eteläistenjärvi (Hauho)
Monitoring of Groundwater Status
The status of groundwater in Häme and the risks arising from human activities have been assessed in the preparation of the third river basin management planning period 2022–2027. According to the assessment, there are no groundwater areas in poor status in Hämeenlinna or Hattula.
Environmental and land extraction permits, regulatory supervision and land use planning play a significant role in groundwater protection. In the risk assessment of environmental permits, which determines the frequency of supervision, location risk factors include, among other things, the location of operations in a groundwater area.
The City of Hämeenlinna and the Municipality of Hattula monitor groundwater quality and level in connection with, among other things, the monitoring obligations of contaminated land remediation projects and old landfills.
Risk Groundwater Areas in Hattula
- Parola groundwater area, where the shooting range poses a nickel risk
- Kerälänharju groundwater area, where traffic and contaminated land pose chloride, heavy metal and solvent risks
Risk Groundwater Areas in Hämeenlinna
- In Hattelmalanharju and Renko Isomäki, traffic and road maintenance pose a chloride risk
- In the Ruskeamullanharju and Kiikkara groundwater areas, agriculture poses a nitrate risk
- In Nummi, the location of the old landfill poses a nitrate risk
- In the Hauskalankangas B groundwater area, the shooting range poses a heavy metal risk