Floodplains: The utility player of flood protection

When you think of flood protection, you likely think of dams and levees. But there’s another element of flood protection that provides many additional benefits – floodplains.

Floodplains are a bit like the utility player in baseball – called on to play a number of positions and always getting the job done. Here are several roles that floodplains play in our communities.

Floodplains reduce flooding
Floodplains are the land along rivers that take on and store excess water during storms and flooding. The water can then be slowly released over time. They help prevent floodwaters from reaching homes and businesses.  Floodplains are essential protection, working in tandem with dams and levees.floodplain

Floodplains protect our groundwater
Water stored on floodplains slowly seeps into the ground and helps replenish our aquifer which holds the region’s drinking water. The Great Miami River and the Buried Valley Aquifer interact with one another. Water from the river seeps into the aquifer during heavy rains/high flows, while groundwater provides flow to the river during our driest months when river flows are low.

Floodplains prevent river pollution
When rivers are running fast during high-water events, so are sediment, nutrients and other pollutants. Floodplains help to slow the river flows and are a place where the water can spread out. When water slows down, it can have the time to drain down through the soil, which filters out pollutants. The plants and trees that grow on floodplains take up excess nutrients; provide shade; and regulate water temperature for aquatic life, which prefers cooler water temperatures.

Floodplains provide for habitat
When land along rivers is not developed, it can provide habitat for many types of wildlife. The plants and trees that grow in floodplains provide places for animals to live. The roots of trees that extend into the water provide habitat for fish and stream insects.

Floodplains provide land for agriculture
With floodwaters come nutrient rich soils, making the floodplain especially good for agriculture, the strongest industry in Ohio’s economy. Many floodplains in our region are valued as prime agriculture lands.

Floodplains provide land for recreation
Floodplains along the river provide land for bike trails. The majority of the year, floodplains along the river remain dry, making the land perfect for bike trails and recreational use. About 60 of the 80 miles of Great Miami River Bike Trail are on MCD-owned land acquired for the flood protection system.  Without these flood protection lands, it would be difficult to have such a long, uninterrupted scenic bike trail through historic and charming riverfront communities. The Great Miami River Bike Trail is part of the nation’s largest paved trail network.floodplain recreation

Floodplains also provide areas where people can reach the river and enjoy recreation and wildlife-watching activities. Places where people can fish, launch a boat, play in a park, or just walk along the river provide the opportunities a community needs to stay healthy and active.

Just like a utility player for a baseball team will likely never be the MVP, floodplains will likely never get the credit that dams and levees do when it comes to flood protection. But they get the job done effectively, efficiently and unassumingly.

Good land-use planning protects floodplains and, in turn, floodplains protect us from flooding and clearly provide many other benefits. Encourage good land-use planning in your community.

 

Potential changes to the region’s drinking water protection plan

Most of us trust our local elected officials with many of the more routine decisions that make our cities hum, without feeling the need to be in attendance. But occasionally, big decisions are made and you want to be there – or at least be aware. On July 29, the City of Dayton will consider important changes to its source water protection program, which is designed to protect the city’s groundwater/drinking water.

The water stored underground in the Buried Valley Aquifer represents the region’s sole and irreplaceable source of drinking water. The Miami Conservancy District’s Aquifer Preservation Subdistrict supports comprehensive protection and management of the region’s water and helps communities develop and implement source water protection plans.

Since 1987, communities that use groundwater for drinking have been required to create plans to protect their water. The Ohio Environmental Protection Agency (OEPA) oversees the source water protection requirements under the Safe Drinking Water Act. The City of Dayton was the first community in Ohio to develop and implement a source water protection program. Currently, the City of Dayton supplies drinking water to approximately 400,000 customers.

The program is multi-jurisdictional and partners with the cities of Huber Heights, Riverside, Vandalia, and Wright Patterson Air Force Base. The source water protection area encompasses more than 6,200 acres.

The City of Dayton has received national attention for its strategy to protect source water while allowing businesses to stay in the source water area. For example, the Risk Point Buy Down Program encourages businesses to permanently reduce chemical inventory through financial incentives. Since its establishment in 1988, more than 25 million pounds of chemicals have been reduced in the source water protection area.

The City of Dayton’s source water protection program has been an exemplary model for communities and is proof that sensible groundwater protection strategies and economic growth can co-exist. Last year, the City of Dayton announced plans to revise the program and asked for comments.

The current proposal:

  • Increases incentive funds for businesses to eliminate hazardous materials.
  • Adds more monitoring wells.
  • Reduces the one-year source water protection area (the area in which contaminants can reach production wells within one year).
  • Allows variances that would increase the inventory of hazardous materials in the source water protection area.
  • Outlines a five-year time-of-travel zone (the area in which contaminants can reach production wells within five years) but doesn’t include any protection regulations.
  • Expands the list of prohibited uses within the source water protection area.
  • Requires more frequent inspections.
  • Increases maximum fines for rule violations.

The Dayton City Commission will meet on July 29th to discuss the proposed changes and consider their adoption. Visit the City of Dayton’s website to better understand what’s at stake and make your voice heard. Email a comment about the proposal to the City of Dayton.

Our abundant source of clean groundwater is one of the region’s greatest assets that sets it apart from other areas of the U.S. Having clean drinking water is paramount to community health and safety.

With water being called everything from “liquid gold” to the “oil of the 21st century,” and because we can’t possibly know the future or foresee all potential contamination sources, protecting source water with as many tools as possible is the wisest choice.

 

Is road salt ruining our water?

By Mike Ekberg, MCD water resources manager

The last couple of winters have had a strong grip on the region, making driving a challenge. Communities across the region use road salt to melt snow and ice and keep drivers safer, but at what cost?

Use of road salt in the northern U.S. has doubled the amount of chloride in rivers and streams in just two decades (1990-2011). “It’s estimated that more than 22 million tons of salt are scattered on the roads of the U.S. annually—about 137 pounds of salt for every American,” according to a Jan. 6, 2014 story at smithsonian.com.

A recent report showed that chloride levels in rivers and streams were highest in the winter, but chloride concentrations were rising even when road salt wasn’t being applied. This suggests that after salt applications, chloride was temporarily stored in shallow aquifers and then slowly released into rivers and streams throughout the year.

Runoff carrying road salt can have negative impacts on aquatic ecosystems but doesn’t present much of a threat in the Great Miami River. Data collected on the Great Miami River near Miamisburg shows that increased chloride concentrations from road salt applications don’t last long and the salt flushes through the river fairly quickly.

Perhaps, a greater threat is that dissolved road salt can penetrate into groundwater used as a source for drinking water. Salt reaching our aquifers (which stores groundwater) does not flush through as quickly as it does in rivers and streams. In extreme cases, improper storage or use of road salt can impact the quality of drinking water.

High chloride levels in drinking water forced the community of Camden to shut down a well in 2010. For years, chloride levels in the aquifer at Camden appeared to be relatively stable. But in 2009, chloride levels tripled, jumping from around 40 milligrams per liter to 120 milligrams per liter. That’s the same year that Camden residents began to complain about a salty taste in their water.

The cause was a large road salt storage facility located near the well field (drinking water source) that was not covered. When rain dissolved some of the salt, it was carried into the aquifer underlying the facility. Eventually, the levels of dissolved salt in the groundwater forced Camden to shut down the well so it was no longer used for drinking water. Camden was forced to seek an alternate source of drinking water.

The U.S. Environmental Protection Agency has set a secondary maximum contaminant level for chloride at 250 mg/L. Chloride in groundwater does not present a direct health risk. It does however present a taste issue when present in high enough concentrations.

After Camden’s experience, a work group, of which I was a member, developed statewide salt storage recommendations. Communities now have guidelines to follow for salt storage including:

  • Guidelines for constructing salt storage facilities.
  • Recommendations for covering salt stored outside.
  • Managing storm water that flows off the storage site.

In addition to implementing guidelines for salt storage, communities can address potential impacts of road salt applications on groundwater through their source water protection programs.

The bottom line is we need to be aware of the most sensitive environments where road salt storage and applications have the greatest potential to get into aquifers. These areas can be mapped and monitored. If chloride levels begin to rise communities can reduce applications in the most sensitive areas near well fields.

map of wells

Notice that the wells with the highest levels of chloride are in developed areas, most likely reflecting impact from road salt applications.

Camden well field stories:

Salt contamination threatens Camden water supply
Camden must connect to water district, Ohio EPA says
Camden in emergency water supply situation, state says
Camden water fix in the works