Lake Creek IA 04-RAC-1163

E ln S12T86NR34W to DD-65/9&13 Calhoun

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.
Trend: Unknown
Created: 11/4/2016 1:48:41 PM
Updated: 11/4/2016 1:48:41 PM

Use Support

Class A1

Presumptive Use

Recreation - Primary contact

Not Assessed

Class BWW2

Aquatic Life - Warm Water Type 2

WINOFI

Fish Kill: Caused By Animal Waste

Support Level

Further Investigation Needed

Impairment Code

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

Cause Magnitude

Moderate

Status

Continuing

Source

Agriculture: Animal Feeding Operations

Source Confidence

Moderate

Cycle Added

2008

Impairment Rationale

Pollutant-caused fish kill

Data Source

Fish kill investigation: Iowa DNR

General Use

General Use water -

Not Assessed

Impairment Delistings

No delistings for this assessment cycle.

Documentation

Assessment Summary

The presumptive Class A1 (primary contact recreation) uses remain "not assessed" (IR 3a) due to a lack of water quality information upon which to base an assessment. The Class B(WW2) aquatic life uses of this waterbody remain assessed (evaluated) as “partially supported” (IR 3b) due to fish kills in July 2005 and August 2006.

Assessment Explanation

The most recent kill occurred on or before August 20, 2006 and was attributed to manure runoff. The kill affected approximately 2.52 miles of Lake Creek on the northeast edge of Rockwell City. An estimated 6,555 fish were killed, although live fish were observed in the stream. The estimated value of the fish was $651.37. The party responsible for the kill was identified, and restitution was sought. NOTE: This assessment was placed in Category 5b of the 2008 Integrated Report due to a lack of information on whether or not restitution was sought for this fish kill. Due to updated information regarding legal action, this assessment was placed in Category 4d of Iowa's 2010 Integrated Reporting cycle. According to DNR's assessment methodology for Section 305(b) reporting, occurrence of a single pollution-caused fish kill during an assessment period indicates "partial support" of the aquatic life uses. If, however, a consent order has been issued to the party responsible for the kill and monetary restitution has been sought for the fish killed, the affected waterbody should be placed in IR Category 4d (impaired but TMDL not required). IDNR considers IR 4d fish kill waters with no subsequent kills in at least the five years subsequent to the kill as appropriate for movement to IR categories 2b or 3b (i.e., Iowa’s list of waters in need of further investigation). Thus, because this kill occurred more than five years ago and because no subsequent kills have been reported, this impairment was moved to Category 3b of the Integrated Report and was added to Iowa’s list of waters in need of further investigation.

The second kill on this segment occurred on or before July 18, 2005 and was attributed to natural causes (water temperature). Approximately 3 miles of stream were affected. Results of the IDNR investigation show that levels of dissolved oxygen were high and levels of ammonia were very low. The kill was attributed to water temperatures that remained in the upper 70s (F) despite a recent rainfall event. The kill affected nongame species; no estimate of the number of fish killed was provided. The observation of live fish suggested that this was only a partial kill. Although believed unrelated to the kill, the Rockwell City area received from 1 to 2-inches of rainfall the evening prior to the kill.

Monitoring and Methods

Assessment Key Dates

7/18/2005

Fish Kill

8/20/2006

Fish Kill

Methods

120

Surveys of fish and game biologists/other professionals

140

Incidence of spills and/or fish kills