Middle Fork Little Maquoketa River IA 01-TRK-138
Alternate name(s) for this segment: Bankston Creek
from west line of S31 T90N R1E (Dubuque Co.) to north line of S33 T90N R1W Dubuque Co.
- Cycle
- 2020
- Release Status
- Final
- Overall IR
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 8/14/2020 1:23:19 PM
- Updated
- 10/15/2020 6:51:34 AM
The Class BCW1 use was assessed as "partially supported" based on based on biological sampling data and continuous dissolved oxygen and temperature monitoring data. All other designated uses were "not assessed".
Sources
of Data: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 BIO See Below 419 Middle Fork Little Maquoketa River Rickardsville – REMAP #261 Class A1 - No Data Class A2 - No Data Class
BCW1 - Biological Sampling: Benthic
Macroinvertebrates: BioNet Site ID Date Drainage Area (mi2) Ecoregion Major Drainage/Thermal BM Sample Gear CBI score CBI Class CBI BIT CBI Pass/ Fail 419 8/31/16 13 52b MS/CW Hess 45 NA 60 Fail 419 7/18/16 13 52b MS/CW Hess 49 NA 60 Fail 419 9/4/12 13 52b MS/CW Hess 35 NA 60 Fail 419 7/23/12 13 52b MS/CW Hess 42 NA 60 Fail Overall
Assessment: Community Assessment Type Assessment Result Support Level Earned IR Category Actual IR Category Reason Benthic Macroinvertebrates Evaluated Fail (0/4) Partial 3bc 5bv Assessment
is evaluated because it included samples not collected in the last five
years. Class
BCW1 - Trout Reproduction: Based on the January 2020 trout reproduction in Iowa streams
summary prepared by the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic
life use of Middle Fork Little Maquoketa River (a.k.a. Bankston Cr.) was
assessed as "fully supported". According to the updated summary, this
stream was placed in Category I: streams that exhibit consistent natural
reproduction and maintain a wild population of one or more trout species
without any stocking. Class
BCW1 - Continuous Monitoring: Results
of continuous dissolved oxygen (DO) and temperature monitoring in 2012 for the
DNR/SHL coldwater stream sampling project suggest impairment of Class BCW1
aquatic life use. The lowest DO concentration recorded in 55 days of continuous
monitoring was 5.7 mg/L. The daily DO minimum concentration failed to meet the
24-hour DO criterion (5 mg/L) in 0 of 55 days. The percentage exceeding (0%)
was less than (passing) the 10% impairment threshold used to assess
conventional water quality parameters. The associated statistical analysis
confidence level was high (>90%). In contrast, the 16-hour DO criterion (7
mg/L) was exceeded in 10 of 55 days. The percentage exceeding (18%) was greater
than (failing) the 10% threshold with high statistical confidence (>90%).
The maximum stream temperature recorded during the sensor deployment period was
22.8 degrees (C). The BCW1 temperature criterion of 20 (C) was exceeded in 22
of 55 days. The percentage exceeding (40%) was greater than (failing) the 10%
impairment threshold with high statistical confidence (>90%). Based on these
data, the BCW1 aquatic life use is assessed as impaired due to DO and
temperature. The assessment type is “evaluated” because it is based on data
collected from a single year within the current data assessment period. In
order to meet the requirements for a “monitored” assessment, the DNR’s
continuous monitoring assessment methodology requires monitoring data from two
or more years within the assessment period. Class
HH - No Data