National Id
Latvia_02
Site name
three sites in Latvia (2 in West Vidzeme and 1 in Kurzeme)
Summary
During last years the construction of the sediment capture ponds as a part of the drainage system has become a good practice measure in the forests managed by Latvian State Forests, therefore some of the environmental impacts of this measures has been monitored to justify its costs. The results indicate differences between monitoring sites set up on mineral or peatland soils as well as between different measured parameters. Additionally, it seems that the effectiveness of the measure depends on the skills and quality of the work carried out by professionals constructing the ponds.
Light or indepth?
Light
NUTS Code
Latvija
Transboundary
0
Data provider
Kristina Veidemane, BEF
Source(s)
Metodes un tehnoloÄ£ijas meža kapitālvÄ“rtÄ«bas palielināšanai
NWRM(s) implemented in the case study
Sediment capture ponds
Climate zone
cool temperate moist
Type
Actual Test Site
Monitoring impacts effects
1
Monitoring location
In-Stream
Administrative annual cost information
The monitoring of effectiveness of the measure has been carried out as a research project.
Monitoring parameters
water quality
Monitoring upstream station
samples were take before the sedimentation pond
Monitoring downstream station
samples wer taken after the sedimentation pond
Performance impact estimation method
Catchment outlet
Performance impact estimation information
assessment of water quality
Application scale
Plot
Lifespan
10
Age
2
Performance timescale
< 1 year
Area (ha)
272
Design capacity
50
Design capacity unit
m
Constraints
Functioning of sediment capture ponds depends on the skill of the professionals who construct it.
Public consultation
0
Contractural arrangements
0
Design contractual arrangement
Arrangement type Responsibility Role Comments Name
Design consultation activity
Activity stage Key issues Name Comments
Design land use change
Land use change type
Design authority
Authority type Role Responsibility Name Comments
Other
Other
Latvian State Forests
State owned forest company which all roles
Other
Monitoring
Latvian State Forest Research Institute &quot;Silava&quot;
State research institute on forest issues
Key lessons
The measures to build sedimentation ponds in forest drainage systems have been implemented in Latvia; however their impact on the water quality has not been evaluated. The case study presents the research results of monitoring of impact on water quality due to installation of the sedimentation pond. The results indicate that the values differ between the years of installement. It is importan that the ponds are installed that the river water can not be flow into the draianage system as well the ponds should be cleaned annually.
Financing mechanism
0
Financing difficulties
0
financing funding solutions
The measure is included as one of the activities carried out for renovation of the drainage system.
Success factor(s)
Success factor type Success factor role Comments
Attitude of relevant stakeholders

The sediment capture ponds are promoted by NGOs and some scientific literature, therefore if the monitoring results in upcomong years will be convincing then the measure could be continued.
Financing
Financing type Comments
Other
The &quot;Latvian State Forests&quot; is state owned company. The measure is a part of renovation and maintenance activities of the drainage system.
Barrier
Barrier type Barrier role Comments
Expected maintenance needs
main barrier
The sediment capture ponds should be cleaned annualy
Other
main barrier
The existing monitoring results does not demonstrate clear effectiveness of the measure as it is implemented at the moment
Driver
Driver type Driver role Comments
Organisation committed to it
main driver
&quot;Latvian State Forests&quot; has introduced this measure as good management practice
Public pressure
secondary driver
NGOs are concerned about the impact of drainage systems on water and fish resources
Financing share
Financing share type Share Comments
Policy description
to prevent erosion and nutrient leackage by reducing stream velocity
Part of wider plan
0
Policy target
Target purpose
Pollutants Removal
Erosion Control
Policy pressure
Pressure directive Relevant pressure
Policy area
Policy area type Policy area focus Name Comments
Policy impact
Impact directive Relevant impact
WFD identified impact
Policy wider plan
Wider plan type Wider plan focus Name Comments
Policy requirement directive
Requirement directive Specification
Costs investment information
the sediment capture ponds are built when the drainage systems are renovated, therefore the direct costs related to sediment ponds are unknown.
Costs operation maintenance
the ponds shall be cleaned annually
Ecosystem improved biodiversity
0
Ecosystem provisioning services
0
Ecosystem water supply
0
Ecosystem impact climate regulation
No specific impact
Water quality overall improvements
Neutral impact-no change in WQ status
Information on Water quality overall improvements
The monitoring results of 2012/2013 differ among sites, and also among chemical elements
Information on Water quality Improvements (P)
The change in P-PO4 (3+) concentrations is different between the sites - some locations show increase, some decreased and in some no change between inlet and outlet of the sedimentation pond.
Information on Water quality Improvements (N)
The change in total N concentrations is different between the sites - some locations show increase, some decreased when the concentrations between inlet and outlet of the sedimentation pond.
Water quality Improvements (TSS)
The change in TSS is different between the sites - some locations show increase, some decreased when the consentrations between inlet and outlet of the sedimentation pond.
Soil quality overall soil improvements
Neutral impact-no change in SQ status