Stream Monitoring & Assessments


Stream Water Quality

Aqua Link is experienced in collecting stream water quality under both baseflow (low flow) and stormflow (high flow) conditions. Stream water samples are collected either manually as grab samples or automatically with electronic water sampling equipment. Collected water samples are analyzed by a certified analytical laboratory for the water quality parameters of interest. 

Our staff routinely collects insitu stream water quality data  (water temperature, dissolved oxygen, specific conductance, conductivity, total dissolved solids, salinity, pH and redox potential) using YSI and HydroLab Sonde equipment. 

Picture - Collecting insitu stream water quality data 


Stream Hydrology & Pollutant Budgets

Aqua Link is experienced in establishing stream stations in order to determine stage and streamflow (stream discharge Q) relationships. Stage is determined either manually or continuously using automated water level logging equipment. Stream discharge is often determined during both baseflow and stormflow conditions. Instantaneous stream discharge (Q) is determined by measuring stream velocities incrementally along known stream cross sections. 

Streamflow data are typically used to determine hydrologic budgets for lake studies. Stream water quality and streamflow data are often used together to determine pollutant (nutrients and sediment) budgets for a stream or an entire lake system.

Picture - Collecting incremental stream velocity and water depth measurements to determine instantaneous stream discharge (Q)


Macroinvertebrates & Fish Surveys

Aqua Link is experienced in assessing macroinvertebrate (e.g., aquatic insects, clams, snails) and fish communities in streams and rivers. Aqua Link utilizes collection methods recommended by the U.S. EPA as part of its Rapid Bioassessment Protocols for streams and rivers and the Mid-Atlantic Coastal Streams Workgroup for low gradient non-tidal streams.  

Macroinvertebrates are collected from non-tidal low gradient streams using D-framed nets, while kick nets and Surber samplers are typically used for higher gradient streams. Fish are typically collected using backpack electroshocking equipment in conjunction with blocking seines.

 Picture - Collecting macroinvertebrates from kick net for later analysis


Stream Visual Assessments

Aqua Link has extensive experience in evaluating the overall condition of streams using Stream Visual Assessment Protocols (SVAP).  As part SVAP, substrate and instream cover, channel morphology, and riparian and bank structure are thoroughly assessed and compared to reference streams. Stream comparisons are based on calculated metrics for the above stream characteristics.

As part of assessing streams using SVAP, all significant stream and riparian problems located using GPS, photographed and ranked by Aqua Link's highly trained field staff. Stream and riparian problem areas (eroding stream banks, excessive siltation/sedimentation, channel scour, poor riparian buffers) are later prioritized for future restoration.

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