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

Name of project which facilitated the documentation/ evaluation of the Technology (if relevant)

Preventing and Remediating degradation of soils in Europe through Land Care (EU-RECARE )

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)

2.1 Short description of the Technology

Definition of the Technology:

Small retention ponds, located in the forest, are ponds or pools with sufficient storage capacity to store the surface runoff to prevent flooding during heavy rainfall events. Ponds contain limited or no water during dry weather, but are designed to retain water during rain events.

2.2 Detailed description of the Technology

Description:

The aim of the small retention ponds is to provide additional storage capacity to hold runoff to attenuate surface runoff - and thus reduce its impact on flooding - during rainfall events. The measure will primarily be useful in connection with short-term extreme episodes and have less effect during prolonged rain – this is because once the dam is filled up it no longer has a flood-reducing effect.

Small retention ponds located in forest areas are artificial dams (up to 2m height, for security reasons) made of soil, stone and/or gabions, with additional storage capacity to attenuate surface runoff during rainfall events. The ponds use local topography to provide space to store discharge peaks. The size of the ponds vary greatly between c. 50-150 m3. The dams can either be established in waterways, or next to the stream so that water is diverted during a flood event. Continuous water flow through the dam is ensured by a spillway located at the bottom of the dam. In this way, the dam can temporarily store water during rainfall episodes and thus decrease the flood peak downstream. The pond must be designed correctly, and calculations of cost-benefit should be carried out before implementation.

As for now, the implementation of small retention ponds in the forests are initiated by landowners. The ponds are getting more and more interest from the local communities however, they are not yet commonly implemented.

In general, there is agreement between experts (researchers) and other stakeholders about the benefits of the implementation of small retention ponds in the forest. However, it is not always the case that such retention ponds decrease floods - as the level of influence depends on the scale and the number of ponds within the catchment. When it comes to drawbacks, stakeholders were particularly worried about the cost of building and maintaining the retention ponds as well as the security of the construction. They placed less emphasis on possible decreases in forest production, which was one of the disadvantages identified by researchers.


Information about the technology is based on investigations and/or reports from different catchments in Norway. For the purpose of the OPTAIN project, the technology is further presented in the natural and human environment context of the Kråkstad River catchment - a Norwegian Case Study catchment within the 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 about 51 km², 43% of which is agricultural land, where cereals are produced on heavy clay 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

2.6 Date of implementation

If precise year is not known, indicate approximate date:

• less than 10 years ago (recently)

2.7 Introduction of the Technology

Specify how the Technology was introduced:

• through land users' innovation
• during experiments/ research

• SMIL

Comments (type of project, etc.):

Establishment of the retention ponds presented in this documentation was initiated by landowners. Monitoring of their effectiveness was part of the research project (RECARE: https://www.recare-hub.eu/).

Retention ponds are part of SMIL subside system (Special Environmental measures in Agriculture)

3.1 Main purpose(s) of the Technology

• reduce, prevent, restore land degradation
• preserve/ improve biodiversity
• reduce risk of disasters
• adapt to climate change/ extremes and its impacts
• mitigate climate change and its impacts

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

Land use mixed within the same land unit:

No

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

• water diversion and drainage
• surface water management (spring, river, lakes, sea)

3.6 SLM measures comprising the Technology

3.7 Main types of land degradation addressed by the Technology

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

4.1 Technical drawing of the Technology

4.2 General information regarding the calculation of inputs and costs

Specify how costs and inputs were calculated:

• per Technology unit

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 =:

8.89

4.3 Establishment activities

	Activity	Timing (season)
1.	Construct the dam	dry period of the year

Comments:

We are talking here about “small” dams, up to 2 m (restrictions due to safety regulations). The dams can be built with the use of typical machinery available at the farms: digger, tractor etc. or with help of company.

4.4 Costs and inputs needed for establishment

If you are unable to break down the costs in the table above, give an estimation of the total costs of establishing the Technology:

35000.0

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

The landowners can apply for subsidies to establish and maintenance sedimentation pond, within SMIL system (Special Environmental measures in Agriculture). Local county authorities are responsible for the administration of these schemes.

Comments:

Approximately NOK 35,000 has been used to establish the retention pond (monitoried withn RECARE project). It is mostly to rent the equipment and buy the material (soil). The work was done made by the landowner.

4.5 Maintenance/ recurrent activities

	Activity	Timing/ frequency
1.	Maintenance of the dam	on demand
2.	Maintenance of the pond area	on demand

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

If you are unable to break down the costs in the table above, give an estimation of the total costs of maintaining the Technology:

10000.0

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

The landowners can apply for subsidies to establish and maintenance sedimentation pond, within SMIL system (Special Environmental measures in Agriculture). Local county authorities are responsible for the administration of these schemes.

Comments:

An estimate for maintenance costs is set at NOK 10,000 annually, most of it is for clearing the area.

4.7 Most important factors affecting the costs

Describe the most determinate factors affecting the costs:

- The terrain setup,
- Type of material used to construct the dam and its durability (establishment and maintenance costs).
- Need for maintenance

The landowners can apply for subsidies to establish and maintenance sedimentation pond, within SMIL system (Special Environmental measures in Agriculture). Local county authorities are responsible for the administration of these schemes.

5.1 Climate

5.2 Topography

5.3 Soils

5.4 Water availability and quality

Is water salinity a problem?

No

Is flooding of the area occurring?

Yes

Regularity:

frequently

5.5 Biodiversity

5.6 Characteristics of land users applying the Technology

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

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

6.1 On-site impacts the Technology has shown

Socio-economic impacts

Production

Income and costs

Ecological impacts

Soil

Biodiversity: vegetation, animals

6.2 Off-site impacts the Technology has shown

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
seasonal rainfall	wet/ rainy season	increase	well

Climate-related extremes (disasters)

Meteorological disasters

	How does the Technology cope with it?
local rainstorm	moderately
local windstorm	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)?

How do the benefits compare with the maintenance/ recurrent costs (from land users' perspective)?

6.5 Adoption of the Technology

• single cases/ experimental

Of all those who have adopted the Technology, how many did so spontaneously, i.e. without receiving any material incentives/ payments?

• 91-100%

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
Improvement of the water conditions down-slope: reduce amount of overland flow and lower erosion rate in the agriculture land located below the pond.

Strengths/ advantages/ opportunities in the compiler’s or other key resource person’s view
Depending on the scale and number of retention pond in the catchment, it may affect the discharge behaviour of the river system (lower peak flows)

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?
Security of the construction
Costs of maintenance

Weaknesses/ disadvantages/ risks in the compiler’s or other key resource person’s view	How can they be overcome?
Decreases in forest prodcution

7.1 Methods/ sources of information

7.2 References to available publications

Title, author, year, ISBN:

Fact Sheets: Case study experiments preventing flooding through small retention ponds. Krzeminska D.; Bøe F.; Stolte J. (2018)

Available from where? Costs?

RECARE project website https://www.recare-hub.eu

Title, author, year, ISBN:

Assessing Impacts of Soil Management Measures on Ecosystem Services. Schwilch G. et al. (2018)

Available from where? Costs?

Mdpi Sustainability

Title, author, year, ISBN:

Helping stakeholders select and apply appraisal tools to mitigate soil threats: Researchers’ experiences from across Europe. Okpara et al (2020)

Available from where? Costs?

Journal of Environmental Management

Title, author, year, ISBN:

Fordrøyningsdammer i tilknytning til jordbruksarealer. Stolte J and Barneveld R. (2019)

Available from where? Costs?

NIBIO raport

7.3 Links to relevant online information

Title/ description:

Fact Sheets: Case study experiments preventing flooding through small retention ponds

URL:

https://www.recare-hub.eu/images/articles/Case_Studies/Fact_Sheets/RECARE_Experiment_Fact_Sheet_NorwayPondsFinal.pdf

Title/ description:

Assessing Impacts of Soil Management Measures on Ecosystem Services

URL:

https://www.mdpi.com/2071-1050/10/12/4416

Title/ description:

Helping stakeholders select and apply appraisal tools to mitigate soil threats: Researchers’ experiences from across Europe

URL:

https://www.sciencedirect.com/science/article/pii/S0301479719317232?via%253Dihub

Title/ description:

Fordrøyningsdammer i tilknytning til jordbruksarealer.

URL:

https://nibio.brage.unit.no/nibio-xmlui/bitstream/handle/11250/2606099/NIBIO_RAPPORT_2019_5_65.pdf?sequence=1&isAllowed=y

7.4 General comments

no remarks