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Furnace Branch (FB-01 and FB-02)

About the site:

New to the Long Term Biological Monitoring Program, sampling began in 2016 at two stations in the study area on Furnace Branch. The reach of interest consists of a concrete channel beginning at a large culvert under New Jersey Avenue, which ultimately drains to a natural channel just upstream of Maryland Route 10. FB-01 is located in the natural channel reach while FB-02 is located within the concrete channel. FB-01 has approximately 41% of its upstream area as impervious surfaces, while approximately 45% of FB-02 is impervious. Removal and restoration of the concrete channel and restoration of the entire stream channel is underway and scheduled to be completed in 2019.



2018 Summary Report:

Site FB-01
Time FrameBIBI (Condition)FIBI (Condition)RBP (Condition)
2018 Results1.00 (Very Poor)* (>60 bugs collected)---90 (Non-Supporting)
Cumulative Average (2016-2018)1.57 (Very Poor)---103 (Partially Supporting)
3-year Running Average1.57 (Very Poor)---103 (Partially Supporting)
Site FB-02
Time Frame1BIBI (Condition)FIBI (Condition)RBP (Condition)
2018 Results1.57 (Very Poor)---67 (Non-Supporting)
Cumulative Average (2016-2018)1.57 (Very Poor)---67 (Non-Supporting)
3-year Running Average1.57 (Very Poor)---67 (Non-Supporting)

Benthic IBI: 

Site FB-01: Sited to be located downstream of the restoration work, this site received a BIBI score of 1.00, or Very Poor in 2018. The sample was automatically given this score due to less than 60 total bugs were collected in the sample. However, of the bugs sampled, the dominant insect was chironomids, with lesser amounts of oligochaetes and some caddisflies, snails, and craneflies. This is synonymous with the last three years of sampling, but with more snails and caddisflies and less chironomids this year. The cumulative (and three year) average score for this site was 1.57 (Very Poor).

FB-01 Sample of Insects Collected by Sample Year

CY01 Bugs
Click to enlarge

Site FB-02: Located within the planned restoration project, this site is situated within a concrete floodway that runs through an unnamed neighborhood park. In 2018, this site received a Very Poor BIBI score (1.57). This site was dominated by chironomids, but also contained snails, damselflies, and caddisflies in its sample. Like the downstream site, this is the first year of sampling as part of this long-term assessment work. The cumulative (and three year) average BIBI score of this site was 1.57 (Very Poor).

FB-02 Sample of Insects Collected by Sample Year

CY01 Bugs
Click to enlarge

Fish IBI:

Site FB-01In 2018, fish sampling did not occur due to restoration of the two sites taking place. However, in 2016, the FIBI score was 2.67, or Poor. Only three species were observed: American eel, white sucker (Catostomus commersonii), and creek chubsucker (Erimyzon oblongus). Notably, this is the only site where these two sucker species were observed. Only nine fish were captured which helped to depress this score. No additional fish data are known for this reach.

Site FB-02In 2018, fish sampling did not occur due to restoration of the two sites taking place. However, in 2016, no fish were found during sampling at this station, so the site received a FIBI of 1.00, or Very Poor. There is virtually no habitat available for fish within this reach due to its heavily armored concrete nature. Additionally, the end of the concrete channel is perched approximately 5 feet above the natural channel downstream, a meaningful barrier to fish movement in this system. Any fish species that did attempt to inhabit this reach would likely be flushed out of the system during storm flow conditions, where velocities regularly reach 4 to 5 feet per second during even modest rain events (≤0.5 inch over variable intervals).

Physical Habitat: 

Site FB-01The RBP score for this site in 2018 was 90, or Non-Supporting. This is lower than the other previous two years of sampling, where the RBP score was 114 (Partially Supporting) in 2016 and 104 (Partially Supporting) in 2017. The cumulative and three year average score for this site was 103 (Partially Supporting). The cross section installed for this site in 2006 could not be recovered. A new monumented section was installed in 2016 and future measurements will allow tracking of this site’s stability. An examination of the photos taken in 2006 versus 2016 provide some qualitative support that this channel has enlarged over the 10 years between measurements. However, additional survey data are needed to confirm if enlargement has actually occurred or is on-going.

Site FB-02Because this site is a concrete channel, the RBP habitat condition was rated as Non-Supporting (67). Only metrics related to bank stability and sediment deposition scored in the optimal range. This is synonymous with the past three year scores of also classified in the Non-Supporting category. The cumulative average score for this site is also 67, or Non-Supporting.. No Rosgen classification was performed at this location. The site is relatively stable as the concrete acts as a bedrock control, but the concrete has numerous areas where it is failing, allowing vegetation to establish itself on exposed and deposited sediment throughout the assessment reach.

Historical Data Summary:

YearBIBI (Condition)FIBI (Condition)RPB (Condition)
20161.86 (VP)---114 (PS)
20171.86 (VP)---104 (PS)
20181.00 (VP)---90 (NS)
YearBIBI (Condition)FIBI (Condition)RPB (Condition)
20161.86 (VP)---71 (NS)
20171.29 (VP)---64 (NS)
20181.57 (VP)---67 (NS)
All Station Summary
 Average BIBI (SD)3-Year Average BIBI (SD)Average RPB (SD)3-Year Average RBP (SD)
FB-011.57 (0.49)1.57 (0.49)102 (12)103 (12)
FB-021.57 (0.29)1.57 (0.29)67 (4)67 (4)
1) No fish collected, so automatically rated Very Poor
* Only one year of data available

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