finland, ruovesi, kulmala wetlandcreation · the aimsand premisesof kulmala wetlandcreation the...
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LIFE+ Return of Rural WetlandsFinland, Ruovesi, Kulmala wetland creation
Wetland area before creation 2011
Photo: Juha Kuukka
Photo: Timo Niemelä
The aims and premises of Kulmala
wetland creation
The aims of the wetland creation:
� To develop model wetland of waterfowl habitat
� To increase biodivrsity in an agricultural area
� To improve water protection
The premises of wetland creation:
� The wetland will be constructed on land owned by the private
� The soil in the area is erosion sensitive, like fine sand and silt
� The catchment area is about 200 hectares and mainly ditched
� It is possible to create the wetland mainly by damming but also digging
will be used to increase the area size
Embankment construction• The base (footprint) of the embankment was cleared of any organic matter prior
to construction
Photo: Timo Niemelä
Installing water control structure
• Full-round flashboard riser made from HDPE (high-density polyethylene) pipe wasinstalled to control water levels and dewater the wetland
• The riser was installed within the existing drainage canal system
• Beavers or muskrats are not present here, so they don´t cause any problems
Photo: Timo Niemelä
HDPE (or ”PE-HD”) fullround flasboard riser
• For pond and wetland water level control
• All joints is important to do with stainless steel screws, mainhole can be locked
• Increase – decrease style of incremental movable boards
Kuva: Timo Niemelä
The costs of the riser:
• diameter 800 mm, height 3000 mm: 1000
€, incl. tax
• inlet and outlet pipes: 560/500 mm SN8
plastic pipes, and other supplies 1 000 €,
incl. tax
• The riser was placed in embankment where the openings and access hatch can be
accessed from shore
Photo: Timo Niemelä
Installing water control structure
• The emergency spillway was constructed to provide an escape for excess water above the
designed level
Photo: Timo Niemelä
Construction of the emergency spillway with stoplogs
• A rocky emergency spillway was designed about 50 cm lower than the settled top of the embankment
• 200 tons of rock were transported to the spillway, costs about 1 050 € (rocks) and 550 € (transporting)
Photos: Timo Niemelä
Construction of the emergency spillway…
• Stop-log system (”wooden wall”) was built of planks size 42 mm thickness x 145 mm width
Photo: Timo Niemelä
Construction of the emergency spillway…
• Stop-log water control structure can be used to regulate water level
Photo: Timo Niemelä
Construction of the emergency spillway…
Embankment construction…
• The embankment was constructed with soil excavated from wetland area
• Soil transporting was done as a voluntary work by the landowner
Kuva: Timo Niemelä Photo: Timo Niemelä
Patopenkereen rakentaminen
Kuva: Timo Niemelä Kuva: Timo Niemelä
• Fill materials was put in lifts about 20-50 cm thick and compacted it by running over the
entire surface with the excavator
• The top of the embankment was built 50 cm higher than designed water level
• The embankment with 1:2 side slopes is enough because suitable grass–cutting machines
are used for side slopes maintanance by the landowner
Summary of the construction works
• The embankment: length 190 m, top width 3,5 m, mean height 1,4 m
• Total costs of the construction works: 63 working hours x 73,80 €/ h = 4649 €, incl. tax
• The excavator: Hitachi Zaxis 210 LC equipped with rototilt head
Photo: Timo Niemelä
Construction of artificial islands and
other excavation work to increase biodiversity
Photo: Timo Niemelä
• Some artificial islands and other resting places were done for waterfowl, also deeper ponds
to create microhabitats for fauna was excavated
• Total costs of these excavation work: 24 working hours x 73,80 €/ h = 1770 €, incl. tax
Kuva: Timo Niemelä
Kuva: Timo Niemelä
Kulmala wetland, total area of 1,3 hectares is favored wetland
for waterfowl like dubbling ducks
Photo: Juha Kuukka
Kulmala wetland 4.7.2015
Photo: Marko Muuttola
Kulmala wetland 4.7.2015
Photo: Marko Muuttola