Central Park Lake IA 01-MAQ-38

Jones County S1T84NR3W 6 mi E of Anamosa.

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 2020 - 2022
Stream/River Water Quality Data	CY 2020 - 2022
Lake Water Quality Data	CY 2018 - 2022
Biological Sampling Data	CY 2018 - 2022*
Fish Kill Data	CY 2018 - 2022
Fish Tissue Sampling Data	CY 2018 - 2022
Continuous Dissolved Oxygen Sampling Data	CY 2018 - 2022
*Biological sites sampled in both 2017 and 2021 were also assessed.

Open Segment Map
View assessment methodology in new window

Cycle: 2024
Release Status: Final
Overall IR: 2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.
Trophic: Eutrophic
Trend: Improving
Trend Comment: Delisted for Chlorophyll a during the 2024 listing cycle
Created: 11/1/2023 8:12:40 AM
Updated: 2/2/2024 3:24:52 PM

Use Support

Class A1

Recreation - Primary contact

Fully Supported

Class BLW

Aquatic Life - Lakes and wetlands

Fully Supported

Class HH

Human Health -

Not Assessed

Impairment Delistings

Cycle Added	Class	Cause	Data Source	Rationale
2008	Class A1	Algal Growth: Chlorophyll a	Ambient monitoring: Iowa DNR-lakes	New data: WQ improvement (chemical / physical / bacterial)

Documentation

Assessment Summary

The Class A1 use was assessed as "fully supported." The Class BLW use was assessed as "fully supported." All other designated uses were “not assessed.”

Assessment Explanation

Data Sources:

Data Source	Data Source ID	Data Type	Data Age	Site ID	Site Name	Site Description
Iowa DNR	6	WQ	CY 2019-2022	22530001	Central Park Lake

Class A1 - Indicator Bacteria: No Data

Class A1 - pH:

Site ID	Data Source ID	# Samples / # Years	Minimum Value	Maximum Value	Mean Value	# Violations	Violations needed for impairment	Violates Significantly >10% Rule?	Assessment Type	Support Level
22530001	6	9 / 3	7.6367	8.5325	8.14	0	3	NO	Mon	Full

Class A1 - Lake TSI's:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	Maximum Value	Median Value	Median TSI Violation?	Assessment Type	Support Level
22530001	6	Chlorophyll a TSI	9 / 3	36	65	50	NO	Mon	Full
22530001	6	Secchi TSI	9 / 3	41	71	58	NO	Mon	Full
22530001	6	Total Phosphorus TSI	9 / 3	37	70	58	NA	NA	NA
22530001	6	Fixed suspended solids	9 / 3	0.6	6	1.9	NA	NA	NA

DNR's assessment methodology indicates that a TSI value less than or equal to 63 is necessary to suggest de-listing of an impairment. The chlorophyll a TSI value for the 2008 assessment listing cycle was 69, which based on DNR's assessment/listing methodology indicated an impairment based on the narrative criteria protecting against aesthetically objectionable conditions. Because the TSI value for the 2024 assessment/listing cycle is less than or equal to the delisting threshold of 63 (median TSI value for chlorophyll a was 50), based on DNR's methodology, these values suggest "full support" of the Class A1 uses protecting against aesthetically objectionable conditions and the impairment (5a) for chlorophyll a is suggested for delisting for the 2024 assessment/listing cycle.

Class BLW - Binomial Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Minimum Value	Maximum Value	Mean Value	# Violations	# Acute / Chronic Violations	Violations needed for impairment	Violates Significantly >10% Rule?	Assessment Type	Support Level
22530001	6	Dissolved Oxygen	9 / 3	4.18	10.77	8.23	1	NA / NA	3	NO	Mon	Full
22530001	6	pH	9 / 3	7.6367	8.5325	8.14	0	NA / NA	3	NO	Mon	Full
22530001	6	Temperature	9 / 3	17.6	27.4	23.8	0	NA / NA	3	NO	Mon	Full

Class BLW - Lake Planktonic Cyanobacteria:

Site ID	Data Source ID	# Samples	Maximum Cyanobacteria Wet Mass	Maximum Cyanobacteria % Composition	Median Cyanobacteria Wet Mass	Median Cyanobacteria % Composition	Median Cyanobacteria Concentration = 75th Percentile	Assessment Type	Support Level
22530001	6	4	10.08192711	74%	3.19290878	59%	NO	Evaluated	NA

Class BLW - Toxic Parameters:

Site ID	Data Source ID	Parameter Name	# Samples / # Years	Maximum Value	Mean Value	Median Value	# Acute / Chronic Violations	>1 Acute / Chronic Violation	Assessment Type	Support Level
22530001	6	Ammonia	9 / 3	0.058	0.02	0.02	0 / 0	NO	Eval	Full

Class HH - No Data

Monitoring and Methods

Assessment Key Dates

6/17/2019

Monitoring Start

10/4/2022

Monitoring End

Methods

200

Physical/Chemical Monitoring

340

Primary producer surveys (phytoplankton/periphyton/macrophyton)