Ann Arbor Water

Flooding can happen quickly—and being prepared can make all the difference. Here's how the City of Ann Arbor and its residents can stay ready before, during, and after a flood:

Ann Arbor is StormReady!
The City’s Office of Emergency Management works closely with the National Weather Service to receive real-time weather alerts. These are shared with the public through:

• Everbridge A2 Emergency Alert System (don’t wait, sign up today!)
• Outdoor Warning Sirens
• Wireless Emergency Alerts (WEA) from the National Weather Service (make sure your phone hasn't opted out of these!)

Stay Aware of Rising Waters
The City monitors water levels using three U.S. Geological Survey (USGS) stream gauges. View current conditions here:

·         Stream Gauge Info

Be Ready at Home
Learn how to prepare your household for flooding with helpful tips and checklists at:

·         ready.gov/floods

Get Emergency Alerts
Sign up to receive critical weather and safety notifications directly to your phone or email:

·         A2 Emergency Alerts

Next time you walk near Barton, Argo, Geddes or Superior dams on the Huron River, take a moment to notice the debris caught in the gates—it tells a story about the human impact on the river. Much of the trash you see didn’t start there. It began on streets, sidewalks, or park trails, where it was left behind or carelessly discarded. Rain can wash that litter into storm drains, which flow directly to the river—one of our drinking water sources.

To help draw attention to this issue, the City of Ann Arbor has a display to show just how much trash accumulates and how it affects both the health of the river and dam operations. When trash gets stuck in the dam gates, city crews must physically remove it—a time-consuming and costly task. And if the trash floats past the dam, it simply becomes someone else’s problem downstream.

The good news is that everyone can help. Here’s how:

• Don’t litter. Even small items like bottle caps, straws, and food wrappers can end up in the river.
• Pick up after others. If you see trash on the ground, consider picking it up—every little bit helps.
• Secure your trash and recycling. Make sure bins are covered and materials aren’t loose, especially on windy days.
• Be a responsible paddler. If you're enjoying the river or the Argo Cascades, bring a bag for any trash and carry everything back with you.

Together, we can protect our waterways, reduce maintenance costs, and preserve the Huron River for ourselves and our neighbors. Clean streets mean a cleaner river—and cleaner water for all.

Construction is progressing steadily at the Barton Dam Right Embankment, where a major infrastructure upgrade will improve dam safety. The project focuses on resolving long-standing seepage issues by replacing the original, failed drain system with a new mineral drain. This upgraded system uses layers of sand and gravel to safely direct groundwater to a collector ditch, helping to protect the dam’s integrity.

This $13 million project (studies, design, construction) is being carried out by Michels Construction, with engineering support from NTH and Geosyntec. It is a required improvement under the Federal Energy Regulatory Commission (FERC) guidelines. Necessary permits were obtained from the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and Amtrak to ensure environmental and site access compliance.

As of July 2025, more than 20% of work has been completed. Please remember that the portage and site are closed and no public access is available. The site is an active and restricted construction zone and unauthorized entry could present a serious safety hazard.

The Michigan Department of Health and Human Services has issued its Safe Fish Guide for 2025. This information is very useful for anyone planning to fish in Michigan’s streams, rivers and lakes. The guide is broken down by region, river area and even gives information about advisories in other states bordering the Great Lakes.

Did you know that Ann Arbor Water keeps a close watch on the Huron River for harmful algal blooms (HABs) and their toxins? 

These naturally occurring blooms—caused by certain types of bacteria called cyanobacteria—can sometimes produce toxins, but rest assured: Ann Arbor’s water is safe to drink.

Our water treatment plant tests for over 200 potential contaminants and runs more than 175,000 water quality tests every year. Our Annual Water Quality Report shows only a subset of these analyses because it does not include contaminants that we do not detect. One of these classes of contaminants that was not detected this year in treated drinking water is toxins from Harmful Algal Blooms. 

We use advanced treatment methods that effectively remove toxins—without needing any changes if a bloom were to occur. We also monitor upstream activity and follow a detailed HAB response plan to stay ahead of any issues.

There are currently no federal regulations for algal toxins, but the Environmental Protection Agency (EPA) offers health guidelines—and Ann Arbor uses even more strict safety limits for all residents. The toxins we test for are consistently undetected or well below those limits.

Ann Arbor’s advisory levels for all consumers are 0.3 parts per billion (ppb) microcystins and 0.7 ppb for cylindrospermopsin. Over the past four years in the untreated source water from Barton Pond, the cyanotoxins anatoxin-a, cylindrospermopsin, and nodularin were not detected, and total microcystin concentrations were below <0.3 ppb.

The City of Ann Arbor's annual fire hydrant flushing will resumed on Monday, March 31. Annual fire hydrant flushing resumes every spring and continues weekly until all hydrants in the city are serviced. This preventative maintenance is done to remove minerals and sediment that accumulate in the water lines over the course of a year. During this work staff will also check and record water pressure to ensure the water system is functioning properly.​​

Where is flushing occurring?

• A graphical map is updated only during annual spring hydrant flushing to show which areas of the city are having their hydrants flushed.
• ​Other preventative maintenance flushing done throughout the rest of the year may not appear on this map.
• ​​You may observe nearby neighborhood fire hydrants with water coming out of the side opening.

On occasion during the hydrant-flushing process, the water in area homes may have an orange or rusty appearance. This discoloration is caused by the disruption to the iron sediment in the water pipes. The water is safe to drink, as the discolored water does not pose a health or safety risk. The discolored water can cause stains to laundry. Temporary laundry coloration caused by this sediment can be removed by using a product called “Rover."​

• If water appears discolored, run the cold water for several minutes and flush your toilets to clear your lines. 
  • Do not run the hot water, as rusty water may get into the hot water tank mixing it with the clear stored water. 
  • If you do get rusty water in your hot water heater, drain the hot water heater per the manufacturer's instructions. 
• ​The water should run clear within a few minutes, but may last until the evening when hydrant flushing stops and more people are home to move the rusty water out of the system.

If you have any questions or concerns regarding hydrant flushing, please call the city at 734.794.6320.

Tour the Ann Arbor Water Treatment Plant, learn from the experts about Ann Arbor's award-winning water and take part in hands-on activities at the Ann Arbor Water Open House Saturday, May 10, 10 a.m.–2 p.m. at 919 Sunset Road. The annual event is free and takes place in celebration of National Drinking Water Week May 4–10.

Get ready to soak in the beauty of the Huron River at the annual Huron River Day (HRD) Sunday, May 18, noon–4 p.m. at Gallup Park (3000 Fuller Road)! This free, family-friendly event is the perfect way to spend an afternoon, surrounded by nature, music and a whole lot of fun. Sponsored by DTE Foundation, this celebration (now in its 45th year) is part of what makes Ann Arbor’s green spaces and happy places so special.

Whether you're walking, driving or biking to Gallup Park, there's no shortage of ways to enjoy the day. Cyclists can take advantage of a complimentary bike valet provided by Common Cycle, making it easy to park and explore. Once you're there, you'll find plenty of hands-on activities, live animals, food trucks and exhibitors showcasing educational and eco-friendly fun! More details will be added later in April. Stay tuned by visiting the event webpage. 

The Ann Arbor Water Treatment Plant (WTP) Facility Plan began in mid-2022. Since then, the team continues to make progress on multiple project tasks. The project includes a strategic plan, an alternatives analysis study, pilot plant testing, and community engagement. For more information about this project, visit the project website.

Following are completed tasks to date as well as what items will be completed in the future.

• Strategic Planning has been completed with the city adoption of the Strategic Plan in February 2024. The Strategic Plan is available to view online.  
• A pilot plant has been constructed at the Water Treatment Plant and became operational in spring 2024. The pilot plant  is where city staff test new technologies, new equipment and treatment methods. At least 12-months of pilot testing is required in the plan. Testing will continue through summer 2025.   
• City staff continue to work closely with the State of Michigan Department of Environment, Great Lakes, and Energy (EGLE) through this process. Together, the city and EGLE have been reviewing pilot plant performance data.
• WTP Facility Plan planning efforts will continue through summer of 2026. Some of the upcoming efforts include:

1. 1. Developing a recommendation on the treatment process selection.
   2. Developing conceptual site plan layouts.
   3. Preparing conceptual construction cost estimates.

On January 28, 2025, key staff from Ann Arbor Water and their engineering consultant, OHM Advisors, came together with city retirees to discuss the city’s water system. Coined as “historians”, these retirees have a vast understanding and knowledge of the city’s water system and were able to provide additional historical context as work progresses on the Water Distribution Plan.

Topics such as pressure districts, connections, redundancy, and emergency response were discussed. Thank you to the following city retirees who shared their experience with the project team: 

• Craig Hupy, former Public Services Area Administrator
• Larry Sanford, former Assistant Water Treatment Plant Manager
• Bill Wheeler, former Public Services Area Administrator 

Adjacent to Barton Pond, Barton Nature Area, Bird Hills Nature Area and trails to and along the Huron River, construction activity continues for the Barton Dam embankment remediation project. Public access is restricted in designated areas. This includes no public on-site access to Barton Pond.  

When visiting this area, please note the posted safety restrictions, barricades and signage on site and use caution in areas that remain open, such as the parking lot, pathway and other areas west of the Huron River, as some of these open areas will be shared by construction operations and construction traffic. This project is anticipated to be completed by June 2027. The city thanks community members for their patience during this Federal Energy Regulatory Commission (FERC)-required project. 

Work continues on the update of the City’s Comprehensive Water Distribution Plan. When complete, this plan will be used to evaluate current practices, ensure preparedness for emergency situations, and ensure a sustainable and resilient water system. The results of this plan, coupled with the results of the Water Treatment Plant Facility Plan, Strategic Plan, and the Source Water Protection Plan will be used to plan,  prioritize, and budget water system improvement projects.

A key part of this work involves the updating and calibration of the City’s Hydraulic Model, which is now complete. A Hydraulic Model is a sophisticated tool that will serve as an essential asset for long-term planning, allowing the City to analyze and optimize water system operations, level of service, enhance fire protection capabilities, and respond effectively to emergency situations.

A Comprehensive Water Distribution Plan involves engagement of key stakeholders, such as the University of Michigan and surrounding communities. The project team continues to connect with these stakeholders to gather their input and understand their current and future needs. The information collected from these stakeholders will be used to assess the future system and identify any capital projects that will be needed to operate the water system efficiently.