Lake Fisher IA 04-FOX-998

Davis County S19T69NR13W 2 miles NW of Bloomfield.

Open Data Collection Period Modal

For purposes of developing stream/river water quality assessments for integrated reporting, three years of water quality data are typically used for both conventional pollutant parameters (e.g., indicator bacteria) and the less frequently monitored toxic parameters (e.g., toxic metals). Since the 2004 IR cycle, DNR has used a three-year data gathering period for streams, rivers, and beaches. For most assessments, the use of three years of data increases the number of samples upon which the decision on use support is based and helps address the problem of weather-related year-to-year fluctuations in water quality.

Due to the lower sampling frequency in Iowa’s ambient lake, biological, fish kill, and fish tissue monitoring programs, five years of data are used for developing IR assessments and for identifying Section 303(d) listings.

Data Type	Data Timeframe
Beach Sampling Data	CY 2012 - 2014
Stream/River Water Quality Data	CY 2012 - 2014
Lake Water Quality Data	CY 2010 - 2014
Biological Sampling Data	CY 2010 - 2014*
Fish Kill Data	CY 2010 - 2014
Fish Tissue Sampling Data	CY 2010 - 2014
Continuous Dissolved Oxygen Sampling Data	CY 2010 - 2014
*Biological sites sampled in both 2009 and 2013 were also assessed.

Open Segment Map
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Cycle: 2016
Release Status: Final
Overall IR: 3 - Insufficient data exist to determine whether any designated uses are met.
Trophic: Unknown
Trend: Unknown
Created: 6/1/2016 3:58:05 PM
Updated: 9/9/2016 10:57:47 AM

Use Support

Class BLW

Aquatic Life - Lakes and wetlands

WINOFI

Fish Kill: Due To Natural Causes

Support Level

Further Investigation Needed

Impairment Code

3b - Use potentially impaired based on an evaluated assessment.

Cause Magnitude

Slight

Status

Continuing

Source

Natural

Source Confidence

Low

Cycle Added

2006

Impairment Rationale

Non Pollutant-caused fish kill

Data Source

Fish kill investigation: Iowa DNR

Class C

Drinking Water -

Not Assessed

Class HH

Human Health -

Not Assessed

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The Class B(LW) aquatic life uses of this waterbody remain assessed (evaluated) as “partially supported” due to a fish kill in March 2004. The kill was attributed to natural causes. This impairment is appropriate for Category 3b of Iowa’s 2016 Integrated Report. The Class C (drinking water) remain "not assessed" due to the lack of recent information upon which to base an assessment. The data used for previous assessments of the Class C uses of this lake are now considered too old (10 years) to accurately characterize current water quality conditions. Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring at this lake. This is the same assessment as that developed for previous assessment/listing cycles.

Assessment Explanation

The Class B(LW) uses remain assessed (evaluated) as "partially supported" due to a fish kill in March 2004.   This kill occurred on or before March 1, 2004; the kill was attributed to natural causes (winterkill).   An estimated 500 fish (gizzard shad) were killed; all fish were approximately 8 to 9 inches in length.   No estimate of the value of the fish killed was provided.   This is the same assessment as that developed for previous assessment/listing cycles.   The continuance of the IR Category 3b listing is based on IDNR's assessment methodology that states the following:  the occurrence of a single pollutant-caused fish kill, or a fish kill of unknown origin, on a waterbody or waterbody reach during the most recent assessment period indicates a severe stress to the aquatic community and suggests that the aquatic life uses should be assessed as “impaired”.   If a cause of the kill was not identified during the IDNR investigation, or if the kill was attributed to non-pollutant causes (e.g., winterkill), the assessment type will be considered “evaluated” and will be placed in IR subcategories 2b or 3b and will be added to the state list of waters in need of further investigation.   Thus, this assessment segment will remain in Category 3b of Iowa’s Integrated Report.   Kills of gizzard shad due to cold water temperatures in winter are common in Iowa lakes and rivers; these kills are typically not related to pollutants or degraded water quality conditions.   Thus, this kill alone, does not indicate an impaired condition of Lake Fisher's Class B(LW) uses.   The presence of gizzard shad in this lake, however, potentially suggests more significant problems for support of the Class B(LW) uses than does a winterkill of this species.

Note: This lake is not part of the ongoing statewide survey of 138 Iowa lakes.

The Class C (drinking water) uses remain "not assessed" due to the lack of information upon which to base an assessment.    The previous assessments of the Class C uses at this lake were based on results of sampling conducted by UHL in January 1995.   However, because these data are now considered too old (greater than ten years) to accurately characterize current water quality conditions, these uses are now considered "not assessed".

Fish consumption uses remain "not assessed" due to the lack of fish contaminant monitoring at this lake.

Monitoring and Methods

Assessment Key Dates

3/1/2004

Fish Kill

Methods

140

Incidence of spills and/or fish kills