Directed Lakes 2015 Sorge-Lake Arbutus Tier II Assessment for 303(d) listing

Purpose

Lake Arbutus was last monitored in 2005 at which time the average phosphorus concentration was 124ug/L and the average Chlorophyll a concentration was 49ug/L. Recent complaints by lake users indicate algal blooms are common and interfering with designated uses of this lake. There are currently no CLMN volunteers associated with Lake Arbutus able to conduct chemistry monitoring. This project would fund a second year of sampling by WDNR to verify, per Wisconsin Consolidated Assessment and Listing Methodology (WisCALM) guidance, whether 303(d) listing is appropriate for this lake.

Objective

Chemistry samples for total phosphorus and Chlorophyll a were collected in Lake Arbutus in July, August and September 2014. The average total phosphorus concentration was 139 ug/L, the average Chlorophyll a concentration was 10.0 ug/L and the average Secchi disc reading was 0.70 meters. Lake Arbutus will be sampled again in 2015 to determine if current in-lake conditions meet water quality standards. There was above average rainfall during June 2014 in Western Wisconsin which possibly led to shorter residence times and subsequently below average Chlorophyll a concentrations. An additional year of sampling may be necessary in 2016 to capture typical in-lake conditions.

Study Design

6 TSI samples will be collected per WisCALM guidance 1 PI survey and NLA shoreline habitat assessment will be conducted in 2016.

Related Reports

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Targeted Monitoring
DL2015_Sorge
2015
Proposed
 
Activities & Recommendations
Monitor or Propose 303(d) Listing
Aquatic Plant Monitoring or Survey