1. Expanding the Limits of Small Stream Biocriteria
NC DWQ
Larry Eaton
Cheryl Gregory

2. NC Small Stream Biocriteria
Developed May 2009 by Eric Fleek
69 page document
Land use is Gold Standard
Qual 4 sampling method
Biotic Index only metric
Index period April, May, June

3. Small Stream Biocriteria (Biotic Index)
Bioclassification Piedmont Mountains
Excellent <=4.36 <=3.75
Good
Good-Fair
Fair
Poor >=6.99 >=6.71

4. Limitations for Use in Restoration Success
Lower limit poorly defined – restorations down to 0.3 mi2, validation only 2 sites below 0.5 mi2
Small Index Period – would be more useful at 6-9 months

5. Study Design (ongoing)
6 Watersheds in Mountains
6 Watersheds in Piedmont
Each watershed sampled 3x/yr
4 size classes in each watershed
<0.1 mi2 (64 ac)
mi2
mi2
>3 mi2
144 Samples Total

7. Biotic Index for Mountain Sites

8. Biotic Index for Piedmont

9. When Method Doesn’t Work
When water is so shallow it will not flow into kick net
When site dries up in summer

10. 1/4” Deep Stream

11. Dry Triassic Stream

12. Ref EPT Taxa Richness (Mtn Streams)

13. Seasonality

14. Summary
In mountains (where most streams spring fed and perennial), method seems to work.
In Piedmont, method limited to streams deep enough to do a kick sample that don’t dry out in summer
There may be a way to incorporate EPT taxa richness into method on a sliding scale of stream size
Data is being collected to see if it is possible to expand index period (maybe with seasonal correction)

15. Questions?