Technologies

Grassed waterways [Norway]

Grasdekte vannveier

technologies_6169 - Norway

Completeness: 94%

1. General information

1.2 Contact details of resource persons and institutions involved in the assessment and documentation of the Technology

Key resource person(s)

SLM specialist:
SLM specialist:
SLM specialist:
Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)
OPtimal strategies to retAIN and re-use water and nutrients in small agricultural catchments across different soil-climatic regions in Europe (OPTAIN)
Name of the institution(s) which facilitated the documentation/ evaluation of the Technology (if relevant)
Norwegian Institute of Bioeconomy Research (NIBIO) - Norway

1.3 Conditions regarding the use of data documented through WOCAT

The compiler and key resource person(s) accept the conditions regarding the use of data documented through WOCAT:

Yes

1.4 Declaration on sustainability of the described Technology

Is the Technology described here problematic with regard to land degradation, so that it cannot be declared a sustainable land management technology?

No

1.5 Reference to Questionnaire(s) on SLM Approaches (documented using WOCAT)

2. Description of the SLM Technology

2.1 Short description of the Technology

Definition of the Technology:

Grassed waterways are shallow channels (natural or constructed) with grass cover, used to drain surface runoff from cropland and prevent erosion.

2.2 Detailed description of the Technology

Description:

In this documentation we focus on the grassed waterways as a measure to carry surface water down the slope without causing soil erosion. The overland flow can be concentrated in topographic depressions, "thalwegs" in the field. Concentrated runoff in such watercourses can create small rills or even gullies. Vegetation/grass disrupt the water flow, but more importantly to protect the soil from erosive forces.

Purpose/aim: Grassed waterways are important conservation measures managing concentrated flow, especially in agricultural areas: runoff concentrates over grassed areas rather than on bare erodible soil (after tillage). They are intended to reduce runoff velocity and soil erosion by grass roots binding the soil. They also help to enhance infiltration, filtering runoff and contribute to sediment and nutrient deposition.

Establishment/maintenance: Grassed waterways are commonly used in areas where waterways are especially erosion-prone. They are normally sited downslope along natural depressions leading water away from agricultural fields. To control surface runoff, grassed waterways are often combined with inlets for surface water leading runoff to drainage pipes.

According to Regional Environmental Programme (RMP) in Norway, permanent grass cover in topographical depressions should be at least 6 m wide. Grass should be sown in the spring to ensure that it is well established in autumn. The choice of grass species depend on whether there is intention of (for example) using the grass for fodder. The grass can be fertilized or treated by herbicides, since they are located inside the production area. The grass can be harvested to maintain land area for food production and reduce nutrient leakage to the watercourse. Area can be tilled only when renewing the grass cover.

An alternative to grassed waterways is to leave the natural waterways covered in stubble over winter (i.e. unploughed). This measure reduces erosion but will not be as effective as grass cover and will not have the same effect on uptake of nutrients as grass cover waterways, as stubble is dead material.

Efficiency /Impact: The effect of (any) vegetation zones depend on several factors such as the flow properties and the characteristics of the vegetative surface. Significant flow properties are velocity (and hence the slope gradient) and water volume, the particle size and concentration of the sediment in the runoff, and duration and intensity of precipitation. For Norwegian conditions there is also the effect of frozen or unfrozen soil and intensity of snowmelt influence on runoff (surface runoff and infiltration).

Studies of Norwegian conditions indicate that the most relevant factor for function of the vegetation zone is the character of the vegetation (height, robustness, and density), rather than the type of vegetation (Blankenberg & Hougsrud 2010). As the efficiency of vegetation comprises a variety of factors, the implementation of the measures is to a large degree site-specific (Kværnø & Stolte 2012).

The effect of grassed waterways on soil loss has been documented in only a few studies. In Norway, only one study examined the effect of grassed waterways in a small agricultural catchment (26.8 daa or 2.68 ha) in Romerike (Akershus, Viken) and it showed 55% reduction of soil loss (average from 8 years) after implementation of grassed waterways.

Natural / human environment: The information about the technology is based on investigations and/or reports from different part of Norway.
For the purpose of OPTAIN project (https://www.optain.eu/), the technology is further presented in the natural and human environment context of the Kråkstad River catchment - a Norwegian Case Study catchment within OPTAIN project.

The Kråkstad River is mainly situated in Ski municipality in South-Eastern parts of Norway. The river catchment is a western tributary of the Vansjø-Hobøl watercourse, also known as the Morsa watercourse. The Kråkstad River catchment area is c.a 51 km², 43% of which is agricultural land, where mostly cereals are produced on heavy clays soils. The main environmental challenge in the area is water quality (incl. high phosphorus pollution) and soil erosion (incl. riverbank erosion and quick-clay landslides).The Morsa watercourse is a drinking water resource and there are specific environmental regulations for land management followed by subsidies through the Regional Environmental Programme (RMP).

2.3 Photos of the Technology

2.5 Country/ region/ locations where the Technology has been applied and which are covered by this assessment

Country:

Norway

Region/ State/ Province:

Viken county

Further specification of location:

The Vansjø-Hobøl catchment

Specify the spread of the Technology:
  • evenly spread over an area
If precise area is not known, indicate approximate area covered:
  • 0.1-1 km2
Is/are the technology site(s) located in a permanently protected area?

No

2.6 Date of implementation

If precise year is not known, indicate approximate date:
  • 10-50 years ago

2.7 Introduction of the Technology

Specify how the Technology was introduced:
  • through projects/ external interventions
  • Regional Environmental Programme (RMP)
Comments (type of project, etc.):

Grassed waterways are measures eligible for subsidies in the Regional Environmental Programme (RMP).

3. Classification of the SLM Technology

3.1 Main purpose(s) of the Technology

  • reduce, prevent, restore land degradation
  • protect a watershed/ downstream areas – in combination with other Technologies
  • adapt to climate change/ extremes and its impacts

3.2 Current land use type(s) where the Technology is applied

Land use mixed within the same land unit:

No


Cropland

Cropland

  • Annual cropping
Annual cropping - Specify crops:
  • cereals - other
  • small grains
Number of growing seasons per year:
  • 1
Forest/ woodlands

Forest/ woodlands

  • natural forest
Waterways, waterbodies, wetlands

Waterways, waterbodies, wetlands

  • Drainage lines, waterways

3.3 Has land use changed due to the implementation of the Technology?

Has land use changed due to the implementation of the Technology?
  • No (Continue with question 3.4)

3.4 Water supply

Water supply for the land on which the Technology is applied:
  • rainfed

3.5 SLM group to which the Technology belongs

  • improved ground/ vegetation cover
  • cross-slope measure
  • water diversion and drainage

3.6 SLM measures comprising the Technology

vegetative measures

vegetative measures

  • V2: Grasses and perennial herbaceous plants

3.7 Main types of land degradation addressed by the Technology

soil erosion by water

soil erosion by water

  • Wt: loss of topsoil/ surface erosion
  • Wg: gully erosion/ gullying
water degradation

water degradation

  • Hp: decline of surface water quality

3.8 Prevention, reduction, or restoration of land degradation

Specify the goal of the Technology with regard to land degradation:
  • prevent land degradation
  • reduce land degradation

4. Technical specifications, implementation activities, inputs, and costs

4.1 Technical drawing of the Technology

Technical specifications (related to technical drawing):

Grassed waterways in topographic depressions in the field

Author:

Lillian Øygarden

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:
  • per Technology unit
Specify unit:

length of grassed waterways

Specify dimensions of unit (if relevant):

meters

other/ national currency (specify):

NOK

If relevant, indicate exchange rate from USD to local currency (e.g. 1 USD = 79.9 Brazilian Real): 1 USD =:

8.99

Indicate average wage cost of hired labour per day:

c.a. 3000 NOK (it is only the cost of the time assuming 8h work per day, 320-500 NOK/hour/ person. Machinery, equipment, materials not included)

4.3 Establishment activities

Activity Timing (season)
1. Plowing before sowing
2. Harrowing before sowing
3. Sowing grass in spring

4.4 Costs and inputs needed for establishment

If land user bore less than 100% of costs, indicate who covered the remaining costs:

Grassed waterways are eligible for subsidies in Regional Environmental Programme (RMP)

Comments:

The costs of establishment and management of grassed waterways are connected to sowing the area and reduced area for cereal production (in case of cereal production farm). The subsidies should be a compensation for such costs. Costs are extremely varied so no estimate is relevant here.

Within RMP for 2019-2022 the subsidy level for maintaining grassed waterways was at the level of 30 kr/m in Viken region.

4.5 Maintenance/ recurrent activities

Activity Timing/ frequency
1. Harvesting grass 2-3 times/yr
2. Plowing In case the re-establishment is needed
3. Harrowing In case the re-establishment is needed
4. Sowing grass In case the re-establishment is needed
Comments:

Grassed waterways are supposed to exist for several years. The grass can be harvested each year (1- 3 times /year) but plowing, harvesting and sowing is only done when the waterway is established or re established.

4.6 Costs and inputs needed for maintenance/ recurrent activities (per year)

If land user bore less than 100% of costs, indicate who covered the remaining costs:

Grassed waterways is a measure eligible for subsidies in Regional Environmental Programme (RMP).

Comments:

The costs of establishment and management of grassed waterways are connected to sowing the area and reduced area for cereal production (in case of cereal production farm). There is no general rule for harvesting. However, if farmers harvest the grass they can get the income. If the grass is not harvested then the production area is reduced. The subsidies should be a compensation for such costs.

Within RMP for 2019-2022 the subside level for maintaining grassed waterways was at the level of 30 kr/m in Viken region.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

The costs of establishment and management of grassed waterways are connected to sowing the area and reduced area for cereal production (in case of cereal production farm). There is no general rule for harvesting. However, if farmers harvest the grass they can get the income. If the grass is not harvested then the production area is reduced. The subsidies should be a compensation for such costs.

The cost of the area management is dependent on:
- Location (priority areas)
- Type of grass
- Possibility to use the grass as a fodder

Grassed waterways are eligible for subsidies in Regional Environmental Programme (RMP).
Within RMP for 2019-2022 the subside level for maintaining grassed waterways was at the level of 30 kr/m in Viken region.

5. Natural and human environment

5.1 Climate

Annual rainfall
  • < 250 mm
  • 251-500 mm
  • 501-750 mm
  • 751-1,000 mm
  • 1,001-1,500 mm
  • 1,501-2,000 mm
  • 2,001-3,000 mm
  • 3,001-4,000 mm
  • > 4,000 mm
Agro-climatic zone
  • sub-humid
  • semi-arid

Thermal climate class: temperate
Thermal climate class: boreal

5.2 Topography

Slopes on average:
  • flat (0-2%)
  • gentle (3-5%)
  • moderate (6-10%)
  • rolling (11-15%)
  • hilly (16-30%)
  • steep (31-60%)
  • very steep (>60%)
Landforms:
  • plateau/plains
  • ridges
  • mountain slopes
  • hill slopes
  • footslopes
  • valley floors
Altitudinal zone:
  • 0-100 m a.s.l.
  • 101-500 m a.s.l.
  • 501-1,000 m a.s.l.
  • 1,001-1,500 m a.s.l.
  • 1,501-2,000 m a.s.l.
  • 2,001-2,500 m a.s.l.
  • 2,501-3,000 m a.s.l.
  • 3,001-4,000 m a.s.l.
  • > 4,000 m a.s.l.

5.3 Soils

Soil depth on average:
  • very shallow (0-20 cm)
  • shallow (21-50 cm)
  • moderately deep (51-80 cm)
  • deep (81-120 cm)
  • very deep (> 120 cm)
Soil texture (topsoil):
  • medium (loamy, silty)
  • fine/ heavy (clay)
Soil texture (> 20 cm below surface):
  • medium (loamy, silty)
  • fine/ heavy (clay)
Topsoil organic matter:
  • medium (1-3%)
If available, attach full soil description or specify the available information, e.g. soil type, soil PH/ acidity, Cation Exchange Capacity, nitrogen, salinity etc.

Soil fertility is medium-high
Soil drainage/infiltration is poor, artificial drainage is needed
Soil water storage capacity is very low-low

5.4 Water availability and quality

Ground water table:

< 5 m

Availability of surface water:

good

Water quality (untreated):

for agricultural use only (irrigation)

Water quality refers to:

both ground and surface water

Is water salinity a problem?

No

Is flooding of the area occurring?

Yes

5.5 Biodiversity

Species diversity:
  • low
Habitat diversity:
  • low

5.6 Characteristics of land users applying the Technology

Sedentary or nomadic:
  • Sedentary
Market orientation of production system:
  • mixed (subsistence/ commercial)
  • commercial/ market
Off-farm income:
  • 10-50% of all income
  • > 50% of all income
Relative level of wealth:
  • average
  • rich
Individuals or groups:
  • individual/ household
Level of mechanization:
  • mechanized/ motorized
Gender:
  • women
  • men
Age of land users:
  • youth
  • middle-aged
Indicate other relevant characteristics of the land users:

Land users applying the Technology are mainly common / average land users
Population density: < 10 persons/km2
Annual population growth: < 0.5%
10% of the land users are rich and own 10% of the land.
90% of the land users are average wealthy and own 90% of the land.

5.7 Average area of land used by land users applying the Technology

  • < 0.5 ha
  • 0.5-1 ha
  • 1-2 ha
  • 2-5 ha
  • 5-15 ha
  • 15-50 ha
  • 50-100 ha
  • 100-500 ha
  • 500-1,000 ha
  • 1,000-10,000 ha
  • > 10,000 ha
Is this considered small-, medium- or large-scale (referring to local context)?
  • medium-scale

5.8 Land ownership, land use rights, and water use rights

Land ownership:
  • individual, titled
Land use rights:
  • communal (organized)
  • individual
Water use rights:
  • open access (unorganized)

5.9 Access to services and infrastructure

health:
  • poor
  • moderate
  • good
education:
  • poor
  • moderate
  • good
technical assistance:
  • poor
  • moderate
  • good
employment (e.g. off-farm):
  • poor
  • moderate
  • good
markets:
  • poor
  • moderate
  • good
energy:
  • poor
  • moderate
  • good
roads and transport:
  • poor
  • moderate
  • good
drinking water and sanitation:
  • poor
  • moderate
  • good
financial services:
  • poor
  • moderate
  • good

6. Impacts and concluding statements

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

crop production

decreased
increased
Comments/ specify:

Land removed from crop production. If harvested as fodder - then contribute positive to income.

Income and costs

farm income

decreased
increased

Ecological impacts

Water cycle/ runoff

water quantity

decreased
increased
Comments/ specify:

Enhanced infiltration

water quality

decreased
increased
Comments/ specify:

Ideally less sediment (and phosphorus) is transported to the surface waters (rivers, lakes), and consequently water quality is increased.

surface runoff

increased
decreased
Comments/ specify:

Due to enhanced infiltration in the grassed areas and reduction of surface runoff velocity

excess water drainage

reduced
improved
Comments/ specify:

When combined with inlet to the drainage system

Soil

soil cover

reduced
improved

soil loss

increased
decreased
Biodiversity: vegetation, animals

Vegetation cover

decreased
increased
Climate and disaster risk reduction

landslides/ debris flows

increased
decreased

6.2 Off-site impacts the Technology has shown

groundwater/ river pollution

increased
reduced

buffering/ filtering capacity

reduced
improved

6.3 Exposure and sensitivity of the Technology to gradual climate change and climate-related extremes/ disasters (as perceived by land users)

Gradual climate change

Gradual climate change
Season increase or decrease How does the Technology cope with it?
annual temperature increase well
annual rainfall increase well

Climate-related extremes (disasters)

Meteorological disasters
How does the Technology cope with it?
local rainstorm well
Hydrological disasters
How does the Technology cope with it?
general (river) flood well

6.4 Cost-benefit analysis

How do the benefits compare with the establishment costs (from land users’ perspective)?
Short-term returns:

neutral/ balanced

Long-term returns:

neutral/ balanced

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?
Short-term returns:

neutral/ balanced

Long-term returns:

neutral/ balanced

6.5 Adoption of the Technology

  • 11-50%
Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?
  • 0-10%
Comments:

There is no trend towards spontaneous adoption of the Technology.

6.6 Adaptation

Has the Technology been modified recently to adapt to changing conditions?

No

6.7 Strengths/ advantages/ opportunities of the Technology

Strengths/ advantages/ opportunities in the land user’s view
Less soil loss
Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Reduced erosion
Improved water quality

6.8 Weaknesses/ disadvantages/ risks of the Technology and ways of overcoming them

Weaknesses/ disadvantages/ risks in the land user’s view How can they be overcome?
Land must be removed from crop production.
Some maintenance is needed periodically so that erosion does not occur along the edges.
Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view How can they be overcome?
No enough research about efficiency of Technology More research

7. References and links

7.1 Methods/ sources of information

  • compilation from reports and other existing documentation

see references

When were the data compiled (in the field)?

11/02/2022

7.2 References to available publications

Title, author, year, ISBN:

Kværnø S., Øygarden L., Bechmann M., Barneveld R. 2020. Tiltak mot erosjon på jordbruksareal. NIBIO POP 6(38)2020

Available from where? Costs?

NIBIO website

Title, author, year, ISBN:

Blankenberg, A-G.B. and Skarbøvik E. 2019. Vegetasjon som miljøtiltak i jordbruket: Varianter, tilskudd og lovverk.NIBIO POP 5(10) 2019

Available from where? Costs?

NIBIO website

Title, author, year, ISBN:

Øygarden L. 2003. Rill and gully development during an extreme winter runoff event in Norway. CATENA 50

Available from where? Costs?

CATENA

7.3 Links to relevant online information

Title/ description:

Kværnø S., Øygarden L., Bechmann M., Barneveld R. 2020. Tiltak mot erosjon på jordbruksareal. NIBIO POP 6(38)2020

URL:

https://nibio.brage.unit.no/nibio-xmlui/bitstream/handle/11250/2723843/NIBIO_POP_2020_6_38.pdf?sequence=4&isAllowed=y

Title/ description:

Blankenberg, A-G.B. and Skarbøvik E. 2019. Vegetasjon som miljøtiltak i jordbruket: Varianter, tilskudd og lovverk.NIBIO POP 5(10) 2019

URL:

https://nibio.brage.unit.no/nibio-xmlui/bitstream/handle/11250/2590439/NIBIO_POP_2019_5_10.pdf?sequence=1&isAllowed=y

7.4 General comments

no remarks

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