three sites in Latvia (2 in West Vidzeme and 1 in Kurzeme)
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.
Kristina Veidemane, BEF
NWRM(s) implemented in the case study
cool temperate moist
Actual Test Site
Light or indepth?
Monitoring impacts effects
Monitoring upstream station
samples were take before the sedimentation pond
Monitoring downstream station
samples wer taken after the sedimentation pond
Performance impact estimation method
Performance impact estimation information
assessment of water quality
Design & implementations
< 1 year
Design capacity unit
Functioning of sediment capture ponds depends on the skill of the professionals who construct it.
Design contractual arrangement
Design consultation activity
|Activity stage||Key issues||Name||Comments|
Design land use change
|Land use change type|
Lessons, risks, implications...
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 funding solutions
The measure is included as one of the activities carried out for renovation of the drainage system.
|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.
The "Latvian State Forests" is state owned company. The measure is a part of renovation and maintenance activities of the drainage system.
|Barrier type||Barrier role||Comments|
Expected maintenance needs
The sediment capture ponds should be cleaned annualy
The existing monitoring results does not demonstrate clear effectiveness of the measure as it is implemented at the moment
|Driver type||Driver role||Comments|
Organisation committed to it
"Latvian State Forests" has introduced this measure as good management practice
NGOs are concerned about the impact of drainage systems on water and fish resources
|Financing share type||Share||Comments|
Policy, general governance and design targets
to prevent erosion and nutrient leackage by reducing stream velocity
Part of wider plan
|Pressure directive||Relevant pressure|
|Policy area type||Policy area focus||Name||Comments|
|Impact directive||Relevant impact|
WFD identified impact
Policy wider plan
|Wider plan type||Wider plan focus||Name||Comments|
Policy requirement directive
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
Ecosystem provisioning services
Ecosystem water supply
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