Green Castle Lake IA 02-IOW-643

Marshall County S8T82NR17W 1 mi. S of Ferguson.

This is a Legacy Assessment. Prior to 2004, assessments were developed under a methodology that pre-dated the Integrated Report guidelines.

Assessment Cycle

1994

Result Period

1990 - 1992

Designations

Assessment Type

Monitored

Integrated Report

Category 0

Trophic

Hypereutrophic

Trend

Stable

Legacy ADBCode

IA 02-IOW-00660-L_0

Overall Use Support

Threatened

Aquatic Life Use Support

Threatened

Fish Consumption

Not assessed

Primary Contact Recreation

Not assessed

Documentation

Assessment Comments

Assessment is based on results of surveys by IDNR Fisheries Bureau.

Basis for Assessment

Fishable uses were assessed as FST and swimmable uses were not assessed for the following reasons: (1) BPJ of DNR Fisheries; (2) results of monitoring in 1990 show that average levels of secchi depth, total-P, chl-a, and TSS are much better than overall averages for the 116 SPOLs sampled in 1990 and 1992; secchi depth is better than the overall mean + 1 SD; (3) Bachmann et al. (1994) report that the lake does not have problems with fishkills; (4) lake has a relatively low sedimentation rate (2.8 cm/yr) and relatively long life expectancy (101 years) for a small impoundment. Although designated for Class A uses, lake does not have a swimming beach and Bachmann et al. (1994) report zero swimming use for the lake; thus, swimmable uses not assessed. Lake threatened by nuisance algal blooms.