Jabez Equipment and Monitoring Overview

Summary:

• Water quality data of four parameters - dissolved oxygen, temperature, pH, and turbidity - have been collected at three sites in the Jabez Branch III tributary restoration, one site upstream of the restoration, and two sites in Jabez Branch.


• Continuous monitoring was conducted with multiparameter sondes at each site, and one-time discrete measurements were taken with handheld meters during each site visit.


• Older sondes (YSI 6600) were initially installed at all sites in 2024 until newer equipment was available. The sondes appeared to experience frequent fouling in pool locations at the restoration sites, and most failed a supplementary dissolved oxygen calibration test.


• Newer sondes (YSI EXO1) were installed at all sites starting in September 2024. These sondes were placed in riffles instead of pools at the three restoration sites to try to reduce fouling. Evidence of fouling continued to be observed.


• In May 2025, MDNR began collecting water quality data with a different model of sondes (YSI EXO3) compatible with wipers that clean the sensors before each measurement is taken, which could improve data accuracy. Trials were conducted with wipers installed on the older sondes at each of the sites. In addition, a new, different model of sonde (YSI EXO3) compatible with a wiper was tested against a YSI EXO1 sonde (incapable of a wiper) at one restoration site. Findings helped justify the procurement of new sondes with wipers.

Overview:

Water quality monitoring related to the Jabez Branch III tributary restoration is being conducted at six sites -- three sites within the restoration reach on the tributary (SEVE-102, SEVE-103, and SEVE-104), one control site on the tributary upstream of restoration efforts (SEVE-108), and two sites in Jabez Branch (SEVE-201 and SEVE-205; see Map tab). One site in Jabez Branch is a control site above the confluence with the restoration tributary, and the other site is below the confluence.

Data are collected at these sites using two methods: continuous monitoring and discrete measurements. Continuous monitoring was conducted with a multiparameter sonde installed at each site. Discrete measurements were taken with handheld meters approximately every two weeks during each site visit when a deployed sonde was removed from the field and replaced with a recently calibrated sonde. These one-time measurements are taken alongside the outgoing and incoming sondes to help check their accuracy.

2024 Continuous Data Collection: Phase I

Early continuous monitoring efforts at these sites have focused on four parameters (dissolved oxygen, pH, temperature, and turbidity) and occurred in two main phases of data collection.

In the first phase from June to September 2024, older sondes (YSI 6600) were installed at the six monitoring sites as a temporary measure until newer equipment ordered for the project was available. Most of these older sondes did not pass a zero DO check, indicating they might be unable to, or experience a long acclimation period before they can accurately read 0 mg/L. All sondes passed normal calibration prior to being deployed or used for taking discrete readings. The zero DO check is an extra check beyond the typical calibration to evaluate the ability of an instrument to accurately read zero DO, as well as how long it takes to reach zero.

The older sondes were installed in pools at each of the three restoration reach sites. Locations in pools were selected in an effort to keep the sondes submerged in water as restoration efforts were expected to result in shallow waters within the reach - as noted in past similar restoration projects. Data from the pool locations, however, indicated potentially frequent fouling of the sondes which subsequently produced what could be inaccurate measurements. Additionally, water levels in the restoration remained higher than initially expected.

2024 Continuous Data Collection: Phase II

The second phase of early data collection ran from September to November 2024. The attached dataset includes continuous readings taken during this period when newer sondes (EXO1) were installed at the six monitoring sites. Newer EXO1 sondes at the three restoration sites were placed in riffles instead of pools with the aim of hopefully reducing fouling on the sondes due to faster moving water. Ongoing construction in the restoration reach converted two of these new monitoring locations (SEVE-102 and SEVE-104) from riffles to pools at some point in October. Ongoing issues with fouling have prompted efforts to procure a different model of sondes (EXO3) which have the ability to use wipers to clean the sensors before each measurement is taken.

During one data collection period from mid-September to early October 2024, continuous data were collected at SEVE-103 and SEVE-104 at the new riffle locations with new EXO1 sondes and at the old pool locations with the older 6600 model sondes. This period of overlap at these two sites allowed for comparative analysis of different locations using different equipment. Discrete measurements were taken in the pool and riffle locations at SEVE-103 and SEVE-104 during site visits on the first day (9/18/2024) and last day (10/2/2024) of that data collection period.

The first deployment of a new EXO1 model sonde at SEVE-102 was in a pool location as a sonde could not yet be installed in a new riffle location at that site. In early October, the new EXO1 sonde was removed from the original pool location and another new EXO1 sonde was deployed in an adjacent new riffle location. Discrete measurements were taken in both the pool and riffle locations at SEVE-102 during the 10/2/2024 site visit.

The sonde at SEVE-205, established as a control site in Jabez Branch upstream of the confluence with the restoration Jabez Branch III tributary, was relocated in September 2024 approximately 40 meters upstream to avoid influence due to an increased area of restoration waters which were flowing directly into the site as a result of beaver activity. Following observations of ongoing influence from the restoration after the relocation, there are plans to move the site farther upstream.

2024 Discrete Data Collection

In addition to the one-time measurements taken adjacent to sondes during site visits, discrete readings were also taken as part of a week-long trial in late October and early November 2024. Discrete measurements taken on four out of seven days were compared to readings from deployed sondes at each site. This trial was conducted to gather additional data showing the rate at which fouling might occur, and to verify our observations that data from the new EXO1 sondes appeared to be potentially impacted by fouling rapidly after deployment.

Sondes with Wipers

In November 2024, a new, different model of sonde (YSI EXO3) compatible with a wiper was tested alongside one of the new EXO1 sondes (incapable of a wiper) at restoration site SEVE-103. Following previous trials with wipers used on the older equipment, this test was conducted to further determine the ability of wipers to potentially improve the accuracy of measurements, particularly those of dissolved oxygen and turbidity. It should be noted that even though a number of older model 6600 sondes available can accommodate wipers, these wipers have malfunctioned on the instruments previously, and cannot be replaced due to outdated/obsolete parts that are no longer available. Additionally, older 6600 sondes are less likely to pass the aforementioned zero DO check. Therefore, the process of purchasing new sondes with wiper capability has initiated as of November 2024. All 2025 continuous data were collected using these new YSI EXO3 sondes with wipers that could help reduce fouling of the sensors and take more accurate measurements.