Category Archives: Stream Visual Assessment Survey

Stream Visual Assessment Survey Data Updated

I have published the recently completed SVAP’s for Beaver Brook here. It also can be accessed through the environmental data tab on the menu bar for the website.

The data is displayed on a map of Beaver Brook color-coded by rating level for each stream feature using ArcGIS Online. It’s fully interactive and, I hope, gives a good snapshot of present stream conditions.

Shu Swamp is now surveyed

This Sunday 16 volunteers, mostly fmembers of Long Island Trout Unlimited, completed 10 Stream Visual Assessment Protocols (SVAP) on Shu Swamp. This completes the SVAP surveys of Shu Swamp, bringing our total number of SVAPs to 15, 5 on the main stream, Beaver Brook, four on the main east tributary into Beaver Brook, and three each on the the main west tributaries.

As described in the Environmental Data link, an SVAP

is a procedure designed for community groups to conduct a simple assessment of stream quality. The protocol includes assessments of stream geomorphology (e.g., how natural the channel is, absence of dams, stream bank stability), characteristics of stream specifically relevant to fish (e.g., hiding places in stream, vegetation canopy, barriers to fish passage), water quality (e.g., evidence of nutrient enrichment, optimal temperature range), and characteristics of stream relevant to the invertebrate food of fish (e.g., available habitats for invertebrates, types of invertebrates). Each characteristic is scored on a scale of 1-10 (usually). An average score is determined with the higher the score the better the stream assessment.

We now have a pretty good first pass on stream quality throughout the system. More extensive and quantitative surveys (called Focused Reconnaissance Assessment Protocols (FRAP), and Detailed Assessment Protocol (DAP)) can focus areas of specific concern. In future posts I will detail the more interesting findings of our SVAPs, (with color-coded maps!). One thing I can say now as a first impression. Sand is really accumulating in the lower reaches of the main stream, particularly after that last rain event in late April. It looks like the main source of the sand is the scouring taking place on the northwest tributary that runs parallel to Dogwood Lane and empties into the main stream just south of the concrete bridge.

And as usual, Shu Swamp flora and fauna never cease to delight: