Catchment work around Lake Vesijärvi Mirva Ketola Lake Vesijärvi Foundation Hola Lake workshop 1 Lahti

Transcription

1 Catchment work around Lake Vesijärvi Mirva Ketola Lake Vesijärvi Foundation Hola Lake workshop 1 Lahti

2 Contents - Catchment of Lake Vesijärvi - Monitoring - Map service - Actions taken in the catchment - Monitoring results from wetlands

3 Lake Vesijärvi A map of Finland + Lake Vesijärvi Lake Vesijärvi Whole lake Enonselkä basin Drainage area 514 km 2 84 km 2 Surface area 109 km 2 26 km 2 Mean retention time 6.8 years 9 years Maximum depth 42 m 33 m Mean depth 6 m 6.8 m

4 Ecological status 2013: Moderate Lake type: Large oligohumic lake

5 Catchment of Lake Vesijärvi: Soil Rock Mixed soils Coarse-grained soil Fine-grained soil Clay Gyttja Peat The catchment includes 20 small lakes (0,5-163 ha)

6 Monitoring of external loading Average size of catchment 934 ha Part of Lake Vesijärvi program 29 streams in Cover 71 % of the area of whole catchment Forests dominate most catchments 2-4 sampling per year Part of the streams monitored also during the Vesijärvi II project in Hammonjoki ha Myllyoja ha Haritunjoki ha Lahden seudun ympäristöpalvelut Juhani Järveläinen /LYP

7 mg TN / l mg TP / l Monitoring Nutrient content ,35 0,30 Phosphorus => High variation Weather conditions Land use 0,25 0,20 0,15 0,10 0,05 0,00 => Long-term average 16,00 14,00 12,00 10,00 8,00 6,00 4,00 2,00 0,00 Nitrogen Lahden seudun ympäristöpalvelut Juhani Järveläinen /LYP

8 Fosfori kg/ha/a Fosfori kg/a Monitoring Nutrient load kg / year Nutrient content x calculated discharge Phosphorus Specific nutrient load kg/ha/year: Load / surface area 0,60 0,50 0,40 0,30 0,20 0,10 Phosphorus 0,00 Juhani Järveläinen /LYP

9 Comparison to earlier results P-load (kg/ha/year) decreased in 9 streams N-load (kg/ha/year) decreased in 5 streams Average change for phosphorus -24 % and nitrogen +4,4 % Järveläinen, J., Malin, I., Mäyränpää, R., Kotakorpi, M. & Kuparinen, M Vesijärveen lasku-uomien kautta tuleva ravinnekuormitus ja sen vähentämismahdollisuudet. Lahden kaupunki, Lahden seudun ympäristöpalvelut. Juhani Järveläinen /LYP

10 Four automated monitoring stations Haritunjoki Myllyoja Purailanviepä (wetland) IN OUT Parameters: water level, conductivity, turbidity, temperature

11 Haritunjoki: Simulated discharge (SYKE) vs. measured water level and turbidity

12 Total P-load kg P/v kg P/y Airborne deposition Areas outside monitoring kg P/y Myllyoja 780 kg P/y Haritunjoki 1420 kg P/y Monitored streams and rivers kg P/y Hammonjoki 500 kg P/y Stormwaters of the City of Lahti kg P/y Kuva: Juhani Järveläinen /LYP

13 Total P load to Lake Vesijärvi ( ) Vesijärvi, TP kg/year Slide: Inese Huttunen, SYKE 12 % 9 % 1 % 3 % 0 % 11 % 7 % 57 % Fields, farming Fields, natural run-off Forestry Forestry, natural run-off Domestic sewage Stormwaters Point sources Fallout pellot peltoviljely kg/v pellot luonnonhuuht. kg/v metsätalous kg/v metsät luonnonh. kg/v haja-asutus kg/v hulevesi kg/v pistekuormitus kg/v laskeuma kg/v Järvi id Lake name Vesijärvi Kajaansel Vesijärvi Laitialan Vesijärvi Komonselk Vesijärvi Enonselkä Vesijärvi Vähäselkä 012 Fields Farming kg/y Fields Natural run-off kg/y Forests Forestry kg/y Forests Natural run-off kg/y Domestic sewage kg/y Stormwaters kg/y Point sources 13 57% 3% 1% 9% 12% 11% 7% retention 91 % kg/y Fallout kg/y Total load kg/y Lähtökuor mitus kg/v Vesijärvi Vesijärvi (stormwaters added)

14 Lahden hulevesikuormitus Enonselälle Stormwaters of City of Lahti are significant source of phosphorus load to Enonselkä basin Heavy metals, suspended solids, patogens => untreated directly to the lake - The strategic top project of City of Lahti - Will cut 8 % of the P-load of Enonselkä Juhani Järveläinen /LYP

15 Sewage treatment in sparcely populated areas and summer cottages?

16 Buffer zones Exist, but no updated statistics Buffer zone in the catchment of Myllyoja Fig. Hanna Eskola

17 Kiikkilä: sedimentation pool in the catchment of Matjärvi Water protection structures Master plan for the catchment of Lake Vesijärvi in 2009.

18 Web pages: puhdasvesijarvi.fi New map service!

19 Web pages: puhdasvesijarvi.fi New map service!

20 Water protection structures Kurhila Äkeenoja Stormwater treatment (open) Wetland or sedimentation pool Ditch bottom filter Bottom dam series Catchment boundary Kytyänoja Filter Pyyrylä Purailanviepä Upila

21 Kurhila Place: Häränsilmänoja Size: 1,4 ha Catchment: 476 ha Fields: 19 % History: Old fish ponds and a sedimentation pool were turned into wetland system in Renovation in 2016.

22 Kytyänoja Place: Myllyoja Size: 1 ha Catchment: 690 ha Fields: 41 % History: Farmer made as water supply in Renovation in 2016.

23 Pyyrylä Place: Haritunjoki Size: ca. 2 ha Catchment: 484 ha Fields: 51 % History: Made in Support for non-productive investement

24 Äkeenoja Place: Äkeenoja Size: 0,3 ha Catchment: 476 ha Fields: 18 % History: Made in Renovation in 2016.

25 Lämpötila C Lämpötila C Lämpötila C Temperature Rise Heavy rain in Kytyänoja YP AP IN OUT Pyyrylä YP AP 20 Äkeenoja YP AP

26 ph No change or rise in early summer IN OUT

27 Conductivity ms/m No clear pattern, decrease in Kytyänoja IN OUT

28 Suspended solids (0,4 µm) mg/l No clear pattern, decrease in early summer, release in autumn? IN OUT Heavy rain on 7.8. clearly increased the load

29 Total nitrogen µg/l No clear pattern, decrease in early summer, release in autumn? IN OUT

30 Total phosphorus µg/l Decrease in early summer, release in autumn? IN OUT

31 Phosphate-phosphorus (0,4 µm) µg/l Decrease? IN OUT

32 Purailanviepä Automated monitoring stations Place: Purailanviepä Size: 0,75 ha Catchment: 700 ha Fields: 43 % History: Made in Renovation in 2015.

33 Conductivity IN OUT

34 Purailanviepä IN OUT

35 Upila Wetland + chemical treatment Place: Upilanoja Size: <0,92 ha Catchment: 300 ha Fields: 45 % History: Made in Renovations of the dam in 2014 an 2016.

36 Saloy Oy chemical treatment with Ferix-3 Chemical formula: Fe2(SO4)3(H2O) Ferix-3 is a dry, granulated form of ferric sulfate that contains about 20% Fe.

37 Upila Clear decrease phosphate-phosphorus IN OUT

38 Upila Decrease in ph Increase in iron and sulphate IN OUT

39 Ditch bottom filter - Suitable for small ditches (catchment some tens of hectars) with high soluble PO4 - With floods part of the water runs over the filter. Other wise tubes direct the water to the bottom of the filter - Phosphorus-binding substance is Nordkalk Grained calcium hydroxide (slaked lime) mixed with gravel

40 Filter Increase in suspended solids? No or slight decrease total P Release or clear decrease in PO4-P!? IN OUT

41 Filter IN OUT Clear increase in ph!!! Conductivity rise in high ph calcite precipitate?

42 Currently searching: Natural based field drainage a pilot example for the farmers FIGS: SYKE

43 Thank you!