Common problems and how to troubleshoot them for wetlands

Common problems and how to troubleshoot them for wetlands

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Symptom	Possible causes	Solution
Vegetation will not establish properly	Water levels need to be maintained per species specific growth patterns during establishment. A secondary water source and flow routing may be necessary to establish vegetation for a year. Soils may not have been properly decompacted during construction. Influent pollutant loads may be harming unestablished vegetation. Wildlife may harm unprotected vegetation.	Consult with the designer to check what water depths should be maintained for the planted vegetation. Consult an engineer to ensure proper decompaction occurred during construction. Install chicken wire or other barriers to deter wildlife from young plantings. Reroute or bypass some of the stormwater carrying harmful pollutants while plantings mature (if pollution is deemed the primary cause). Review nearby winter maintenance activities to see if runoff with high concentrations of chloride is reaching the practice. Vegetative maturation may take two growing seasons.
Stagnant water	Significant erosion that has impacted hydraulics. Clogs in the conveyance network. Grading issues.	Remove any sediment or soil that has sluffed into the treatment pools due to erosion. Check and remove debris or clogs from all conveyance structures. Consult the designer or an engineer to identify grading or other hydraulic issues.
Mosquitos	Optimal breeding conditions	Address stagnant water Modify water level controls to increase velocity Introduce predators (fish and/or invertebrates)
Wetland capacity is reduced	Sediment build up or vegetative overgrowth	Remove accumulated sediment Harvest vegetation
Flow or water imbalance (more water coming in than going out), lower than expected water levels.	Unanticipated infiltration	Check the integrity of any impermeable barriers or linings that were installed beneath the growth media.