Timo Yrjänä LAKEPROMO 25.-26.11.2006 Kuopio

1. Timo Yrjänä LAKEPROMO 25.-26.11.2006 Kuopio Lake restoration -co-operation between inhabitants, city and state -examples from Northern Finland Järvien kunnostaminen kansalaisten, kunnan ja valtion yhteistyönä -esimerkkejä Pohjois-Pohjanmaalta.

2. NOREC and lake restorationNOREC=Northern Ostrobothnia Regional Environment Centre • Priorisation of initiatives made by stake-holders – use and nature values (I-III) • National/international – planned and organised by NOREC, inhabitants and city are partners • provincial –stakeholders, city/and state operate • local – stakeholders do, NOREC gives advices

3. Some priorisations in 2004… • Pyöriäsuon turvetuotantoalueen muuttaminen lintualueeksi, Yli-Ii, 20.2.2004 III • Mustaputaan vedenvirtauksen edistäminen, Ylikiiminki, 20.2.2004 III • Iso-Orastinjärven kunnostus, Ii, 20.2.2004 III • Tikkakosken korjaaminen, Alavieska, 30.31004 Hylkäys • Tulijärven tilan parantaminen, Muhos, 30.3.2004 II • Lamujoen Alikosken kalataloudelliset kunnostukset, Piippola, 30.3.2004 III • Vuohtajärven Vattulahden kunnostus, Reisjärvi, 30.3.2004 III • Iso-Olvasjärven parantaminen, Utajärvi, 27.4.2004 II • Naisjärven kunnostus ja pohjapatojen rakentaminen, Pudasjärvi, 27.4.2004 III • Uuranputaan kunnostus, Pudasjärvi, 27.4.2004 III • Oijärven kunnostaminen, Kuivaniemi, 15.6.2004 I

4. Planning and financing • Lake Torankijärvi: • Consultant office (aeration), City and NOREC officers, project workers • City of Kuusamo+EVO+NOREC • EVO=Energy and water co-operative… • Lake Saunajärvi: project worker, consultant office • ERDF, City of Pudasjärvi, local people • Lake Pirttijärvi: • Master Thesis, consultant office • Cottage owners (50%)+City of Muhos, NOREC • Regulated lakes in Kalajoki watershed • NOREC

5. Lake Torankijärvi (A=226 ha, shallow) • Load: waste waters of Kuusamo city • directly to the lake 1940’s-1950’s • Sedimentation ponds in 1960’s • 1973 biosorption pond • Modern waste water treatment plant 1982 • Internal load, Algal blooms, no fishing (bad quality of fishes • NATURA 2000 – resting place for birds • Park area for the city

6. First restoration plan in 1985 -Aeration 1985 *Planox *EVO, compensation from waste waters -Dredging of shallow vegetation areas (NOREC, City) Aim: to improve lake scenery Results: *”park like” bank line without aquatic plants *increasing phosporus content *algal blooming, reduction in the bird populations

7. New restoration measures • Bad reputation: no swimming, no fishing… • Conflict: heavy restoration measures><Natura 2000 (bird habitats) • Torankijärvi council • City, water and land owners, bird watchers, NOREC (waste water+bird+restoration officers, EVO… • yksimielisyys, sitoutuminen • New restoration measures fot the period before final solution where to lead the waste waters…

8. Measures in 2000’s • To reduce internal load • Aeration • Biomanipulation • To improve recreational value of the lake • Cutting of trees and bushes from coastal area • Building of bird watching tower

9. Aeration 2002- • One old Planox: O2-content in late winter 2,5-4 mg/l, nutrient lead from sediment, fish kills • leasing of 2 new Mixox (MC750), all around the year + 1 AireO2 in winter (5,5 kW) • Minimum O2-content in late winter 1,7 mg/l from year 2002, amount of nutrients in lake water in summer: variable, declining direction?,

10. Biomanipulation • 3 project workers –1 fyke net+90 metal wire traps, local professional fishermen (0,5 €/kg) – seine net • 2001: 36 kg/ha, 2002: 39 kg/ha, 2003: 42 kg/ha, 2004 ? • 2003: professionals 5100+project workers 4400 kg • Both are needed

11. Relation of total phosphorus and chlorophyll contents in summer in Lake Torankijärvi

12. Lake Saunajärvi (A=80ha, shallow) • Forest lake (80% from catcment area), some summer cottages and a camping resort, originally clear water, rarely stratified, O2 depletions, algal blooms, decreased recreational use • External load 19 kg/ total P in year – forestry operations most important source, internal load - estimated to be remarkable

14. Phosphorus load to the Lake Saunajärvi

15. Restoration measures • Fish removal during 15 years • first local fishery organisation • 2001 ERDF-project, local fishermer participate • Financial support for waste water treatment systems of summer cottages

16. Fish removal

18. Effects of restoration measures to phosphorus content inlake Saunajärvi

19. Lake Pirttijärvi (A=36 ha) • Shallow lake, mean depth 1,55 m, 2 m soft sediment on the bottom (max. 5 m) • Eutrophicated (a-chlorophyll 56-89ug/l,tot-N 815ug)l, tot-P 45 ug/l) • Algal blooms, earlier forestry operations, summer cottges • Cottage owners pay half of the cost, which are 54 000 €

20. Pirttijärvi-temporary drying • 800 m of natural outlet has been dredged during this autumn • Sedimentation pond • Regulation dam have been constructed • Water will be led out during next winter • People can reconsrtact they own strand areas • Lake will be filled again using spring flood in 2006

21. Effects of temporary drying • Sediment becomes more tight/solid • It will get hard surface layer • Increase in water volume • Wind will not mixe the bottom sediment (as much as before) • Total fish removal, regulation dam is a migration barrier > possible to control fish population in future

22. Pipe-aeration apparatus Principle Propeller circulate oxygen rich surface water to the depth of 5 meter Amount of circulated water 400l/s

23. Pipe aeration apparatus mix water layers and equalize oxygen content, Regulated lake Vuohtojärvi, winter 1995-1996

24. NOREC has aerasted regulated laks in Kalajoki watershed during ten yers Lakes which most often have needed aeration: Hautaperä Reservoir, Lake Vuohtojärvi, Lake Kiljanjärvi and Lake Kuonanjärvi

25. Brush aeration apparatus in Lake Kuonanjärvi 2001 Beacaue of aeration oxygen content was moderate in late winter despite of remarkable reduce in water level.