Changes in groundwater levels?

By Mike Ekberg, Manager for Water Resources Monitoring and Analysis

Groundwater levels in the aquifer beneath downtown Dayton fluctuate throughout the year. Locally, groundwater levels often peak in winter or spring and decline to their annual low in the fall. However, we’re seeing changes to the normal up-and-down cycle of groundwater in the aquifer in a couple of downtown wells.

Graphic of depth to groundwater

Groundwater levels fluctuate throughout the year. But the annual low groundwater level at the Apple Street and South Main Street observation well shows a decline over the past 25 years.

The annual low groundwater levels in two downtown observation wells are showing a distinct downward trend, declining as much as 25 feet over the past 10 years. In fact, recent groundwater levels at both wells tend to be below monthly normals for much of the year. What’s causing the drop?

Geothermal systems may be the reason
An increase in geothermal heating and cooling systems in Dayton may be the cause. In the last 15 years or so, several buildings in downtown Dayton installed open loop geothermal systems. Open loop systems pull groundwater from high-capacity wells —tied to the aquifer beneath Dayton—to create heat and air conditioning.

If too many geothermal systems draw water from the same area, that could cause a significant drop in average groundwater levels. That’s happening now in these two wells in downtown Dayton. And yet, these wells—and the Dayton area–still have plenty of groundwater

Water supply safe
Is the aquifer going to go dry? Not likely. The buried valley aquifer, which stores this region’s groundwater, holds 1.5 trillion gallons of water. That said, in areas where a lot of groundwater is pulled from the aquifer, it’s possible for one well to cause another well to go dry. This situation is most likely to occur during summer months when water demand for cooling systems peak.

MCD tracks groundwater levels at more than 100 monitoring wells in the region. The City of Dayton tracks groundwater levels at more than 300 monitoring wells throughout its well fields and within the aquifer. City officials say their well field areas are not impacted by the pumping of groundwater downtown.

Can geothermal systems continue to be a workable option for Dayton buildings? Yes, provided there’s a plan to balance the number of systems and well locations.

Better water planning prevents problems
Steps to ensure this balance include:

  1. Inventory high-capacity geothermal wells in the downtown area.
  2. Fully understand current groundwater levels throughout the area.
  3. Assess the potential impact of new geothermal wells on existing wells and storm sewers.
  4. Site wells strategically.

With these steps, Dayton—and other cities—can ensure existing geothermal systems will not be harmed by adding new systems, and all the systems will be sustainable.


El Niño 2015/16: A recap

El Niño contributed to a mild winter in the Miami Valley

By Mike Ekberg, water resources monitoring and analysis manager

If you thought the region got off easy this winter, you’d be right.  And you can thank El Niño.

El Niños  produce drier and warmer than normal winters
El Niño affects weather worldwide by changing the way air circulates in the atmosphere.

El Niño is a weakening of eastward blowing winds over the Pacific Ocean creating warmer than normal water in the eastern Pacific Ocean near the equator.El Nino graphic

El Niño tends to keep the polar jet stream—and cold arctic air—farther north and out of the Miami Valley. It also tends to shift the Pacific jet stream—and winter storm systems—to our south. Together these patterns tend to produce warmer and drier winters locally.

Above average temps and precip
Average monthly temperatures for January through March were well above normal, according to the National Oceanic and Atmospheric Administration (NOAA). Dayton saw above-normal daily average temperatures all three months. This is exactly what we expect during an El Niño winter. The 2016 winter was the 10th warmest recorded for this region, dating back to 1895.

Precipitation was near normal, with an average of 8.94 inches in the Miami Valley. That’s 0.87 inches above normal. January and February precipitation were below normal, but March was above normal. So winter 2016 brought more precipitation than expected for an El Niño winter.

It’s anyone’s guess as to why precipitation was greater than expected. Other factors besides El Niño influence local weather. Sometimes the random nature of weather is beyond our ability to predict.

La Niña on the way?
While El Niño 2015/16 was one of the strongest ever recorded, it’s weakening. Most climate forecasts predict it will end during late spring or early summer and will eventually change over to a La Niña phase. Some forecasters expect that shift this summer.

It’s too early to tell how La Niña conditions in the Pacific Ocean will shape our next winter. Stay tuned.


Well Owners – Is your drinking water safe?

Contamination is more common than you think

By Mike Ekberg, MCD manager for water resources monitoring and analysis

Hey well owners, when’s the last time you had your drinking water tested? If you’re like many well owners in the United States, you probably have never tested your water. Why should you bother? You have plenty of water and it tastes good, right?

If you want to be sure your drinking water is safe, you need to get it tested.

Test at least annually
The National Ground Water Association (NGWA) recommends well owners test their water at least annually for bacteria, nitrates, and contaminants specific to your area. Consider more frequent testing if:

  • There is a change in taste, odor, or appearance of well water.
  • The well has a history of contamination.
  • The well is near a failing septic system.
  • There have been recurring incidents of gastrointestinal illness.
  • An infant is living in the home.
  • Home water treatment equipment has been installed.

In our area, I recommend the following tests:

E. coliE. coli bacteria is a specific indication of fecal contamination in the well. Its presence is a warning that disease-causing bacteria may have entered the well.

Nitrate – Nitrate gets into drinking water from fertilizers, manure, and septic systems. It also occurs naturally. High nitrate levels present a health concern for infants if the water is mixed with formula. High nitrate levels can also suggest other toxins such as bacteria and pesticides.

Arsenic – Arsenic is naturally occurring in groundwater. It’s linked to various cancers and other health issues.

Manganese – Manganese also occurs in nature and can be present in groundwater. At high enough levels, it may cause brain damage.

Lead – Lead typically gets into drinking water from corroded pipes and plumbing fixtures. If your home was built prior to 1986, it’s more likely to have lead pipes, fixtures, and solder.


Get help with testing
The Ohio Environmental Protection Agency has a website with contact information about state-certified labs that can help with testing. Contact a lab and have the staff help you collect water samples and explain the results.

Ohio State University (OSU) also offers an on-line tool to help you understand the results. The OSU site offers a lot of information for well owners.

Bigger problem than you think
Recent studies show that private well contamination is not rare. A 2009 United States Geological Survey study of more than 2,000 private wells found about 23 percent of the wells had problems. More recently, MCD surveyed 107 private wells. Twenty percent of those wells had unsafe levels of arsenic in the water.

The need for testing is real. Now go out and get your water tested!


Could a drinking water crisis be headed our way?

Water quality crises are becoming more common, from algal toxins in Toledo to lead in Flint, Michigan; Sebring, Ohio and other communities. Could those crises happen here?

It’s possible—but not likely—because this region pulls almost all of its drinking water from groundwater stored in the buried valley aquifer, not from rivers and streams as these highlighted cities do. Why is groundwater better?

Groundwater offers several benefits over surface water (rivers and streams) for drinking.

  • Treating groundwater so it can be used for drinking water can be simpler than treating surface water. Groundwater may only need to be disinfected to kill bacteria and viruses, while surface water must be disinfected and filtered for other pollutants.
  • Groundwater in our region tends to be alkaline and not as corrosive to pipes as natural waters from other parts of the state.
  • Groundwater is commonly ‘softened’ during treatment which tends to reduce the buildup of scale on pipes and plumbing fixtures.
  • Surface water can be affected by polluted runoff from many different land uses including rural and urban land activities. This runoff can include bacteria and chemicals that are difficult or costly to treat.
  • Algal blooms, which are fed by polluted runoff flowing into rivers and streams, do not occur in groundwater because algae cannot live underground.
  • Spills of toxins or other contaminants into rivers and streams can flow downstream quickly for hundreds of miles, potentially reaching the intakes to water supply. Groundwater typically moves slowly, so there is time to prepare or to clean up contamination before it reaches water supply wells.

Protecting groundwater is key

The key is protecting groundwater and preventing contamination. Contaminated groundwater tends to stay contaminated for a long time. Once groundwater becomes contaminated, it’s often very difficult and costly to cleanup.

Advances in groundwater cleanup technologies have been made over the last several decades, but groundwater quality often can’t be restored to previous conditions.

Fortunately, for those of us who live, work and play in the Miami Valley, we can rely on the buried valley aquifer system to provide us with a reliable source of drinking water. Provided, that is, we are willing to do the things necessary to be good stewards of this resource and protect it for our future.

Communities can help

Every community in the Miami Valley has an important role in keeping our water clean and safe.

Make sure that your community has an up-to-date and thorough source water protection plan that is implemented. A source water protection plan protects your community’s water supply.

Communities can protect water by updating their development policies including zoning, codes, ordinances, and subdivision regulations. There are easy and economical ways to do a better job of developing land while protecting water.

Municipalities can also take steps to help residents learn how to ensure the quality of our groundwater. Educate your residents:

  • About the dangers of pouring household cleaners, paint and other chemicals onto the ground, and share information about proper disposal.
  • How to report spills.
  • How to use pesticides and fertilizers sparingly.
  • How to carefully change the oil in their cars, avoiding spills that could make their way to the storm drain. Ensure your community has an oil drop off program.
  • How to responsibly dispose of unwanted medication, and provide prescription drop-off events.

2015 in Review: A Wet Year

The year 2015 has come to a close and before we get too far into 2016, I thought it might be interesting to review the year from a hydrologic perspective given all the recent attention to El Niño and the December 27-30 high water event on the Great Miami River and its tributaries.

The Great Miami River Watershed received an average of 45.26 inches of precipitation in 2015. The 30- year average annual precipitation is 41.18 inches, so 2015 was well above average.

Precipitation was significantly above average during the months of April, June, July, and December. February, May, and September were significantly drier than normal. No record highs or lows were set in 2015.

Above-average precipitation in 2015 led to above average runoff. Runoff is the amount of water carried out of a drainage area by streams. Runoff for the Great Miami River was measured at 18.37 inches for the year, which is 5.34 inches above average.

At least one Miami Conservancy District dam stored water on 12 different occasions in 2015. The average number of annual storage events for the MCD flood protection system is eight. The largest storage event was the December 27–30 event when all five of MCD’s dams were storing floodwaters. Together the dams stored 14.2 billion gallons of water behind the dams. This event ranked as the 32nd largest storage event in MCD history.

All in all, 2015 was a continuation of a rising trend in precipitation for our region. The chart below shows how the 30-year average annual precipitation for the Great Miami River has changed since 1985, and has been rising sharply since the 1990s. What can we expect if this trend continues? The answer is more rain, more runoff, and more high-water events.

30-year precip chart

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.


Winter 2016 and “The Mother of all El Niños”

El Niño is getting a lot of media attention these days being blamed for floods, famine, and the spread of diseases. This year’s El Niño is shaping up to be one of the stronger, if not the strongest, El Niño in history. In fact, it’s drawing comparisons to the 1997 El Niño event, which is the strongest El Niño on record and sometimes called “The Mother of all El Niños.”

According to the National Oceanic and Atmospheric Administration (NOAA), the current El Niño event in the Pacific Ocean is expected to peak in December, but the impacts of El Niño are expected to last well into the spring of 2016. These impacts are likely to influence weather in our region.

El Nino comparison

Comparison of 1997 El Niño (left) and 2015 El Niño

When it comes to Earth’s climate, weather phenomena happening in faraway places can sometimes have dramatic impacts locally. El Niño is characterized by unusually warm ocean temperatures in the Equatorial Pacific Ocean. The image above shows areas of the Pacific Ocean with above-normal water temperatures colored in red in August of the 1997 El Niño event and August of 2015.

When El Niño occurs, very warm waters in the Pacific Ocean pump more moisture into the atmosphere. This impacts and changes the direction of major wind currents, steering weather systems across the United States. In other words, the typical storm paths in the United States are shifted. Typically, El Niño shifts storm tracks south during the winter months resulting in increased precipitation across the southern tier of the United States. At the same time, El Niño tends to bring warmer-than-normal temperatures to Alaska, Canada, and the northern tier of the United States. 

2016 3 month precipitation outlook

2016 3-month precipitation outlook

So what El Niño effects can our region expect
to see for the upcoming winter and spring?  According to NOAA’s climate prediction
, our region is likely to experience a mild winter temperature-wise with below-normal precipitation. The image on the right shows areas of the United States expected to have above-normal precipitation in green and
below-normal precipitation in brown over the next three months. Most of Ohio is colored in brown. The outlook for spring is similar, with near-normal temperatures and below-normal precipitation.

Is this forecast a sure bet? It isn’t. The Earth’s climate systems are extremely complex, and El Niño is only one of many factors influencing our weather. The temperature and precipitation outcomes we experience this winter are a result of a multitude of complex interactions among the Earth’s weather systems. We can only wait and see!

Stream Gages: Commitment yields benefits

In our last blog post, “Gauging the Value of Gages,” we discussed the importance of stream gages to The Miami Conservancy District’s (MCD) flood protection activities. Now let’s talk about the importance of stream gage information on riverfront development, infrastructure projects, public safety, and water quality.

Stream gage network benefits

Stream gages provide reliable estimates of peak river flows that must be incorporated into engineering designs for infrastructure in floodplains and river channels. The infrastructure includes everything from levees, bridges, bikeways, boat ramps and docks, riverfront parks, kayak runs, and water and wastewater treatment plants. Imagine the implications of building riverfront projects and bridges without knowing how high the river will rise.

Stream gage information allows recreational paddlers and boating clubs to determine whether or not it’s safe to go out on the river. It is also used to determine when river corridor bikeways are dry and safe or whether portions are under water.

FEMA uses river studies to develop more accurate FEMA floodplain maps. Those river studies rely on data from stream gages.

Wastewater treatment plant permits regarding discharging pollutants into waterways are often based on certain river flows. Stream gages can be used to determine these river flows.

How a stream gage works

A stream gage measures the elevation of the water surface at a particular point in the river channel (not the entire river channel). We call the elevation of the water surface the stream or river stage.

Stream gages do not directly measure flow. To measure flow, MCD staff goes into the river with instruments that measure discharge – usually measured as cubic feet per second.

Discharge measurement on Holes Creek near Kettering

An MCD staff member takes a discharge measurement on Holes Creek near Kettering.

If we measure the discharge in the river channel over a wide range of river stages, we can develop a mathematical relationship between stream stage and discharge that estimates the amount of discharge for any given stage.

This relationship is called a rating curve. Once the rating curve is developed for a stream gage, we can determine reliable estimates of river flows.

This is important because it is not cost-effective, practical, or safe to send staff into the river every time that information is needed. Steam gages measure stage on a real-time basis, so with the rating curve, stream flow can be estimated on a real-time basis. Historic records of actual stream flow conditions allow us to predict future conditions, including peak flows.

The Great Miami River Watershed Stream Gage Network

The stream gage network in the Great Miami River Watershed consists of 25 stream gages. These gages are also part of the United States Geological Survey (USGS) national stream gaging network. MCD purchases most of the equipment and provides most of the field labor to maintain the gages. USGS manages the data, providing the ability to transmit data through GOES satellites, and allowing users to access the data through the National Water Information System (NWIS).

This stream gage network is funded by a combination of federal and local funding sources. Federal funds are provided by USGS and the U.S. Army Corps of Engineers. Local funding is provided by MCD.

Protect the value of stream gages

Everyone needs stream gaging information to support good engineering design and flood forecasting. A reliable stream gage network is integral for regional efforts to improve flood preparedness, develop new riverfront corridors in our cities, improve water quality, and support recreation on our rivers and streams. Without the network, we would be flying blind.

Most people think information that comes from stream gages is just a matter of installing a sensor somewhere and letting it do its thing. Unfortunately, it’s not that simple. It takes time – lots of time, if you do it right. And that costs money, from equipment to staff time.

Each year, funding for the national stream gage network is threatened with cuts to the federal budget. Please let your local congressman know it’s important to protect and support our system of stream gages and data transmission satellites so it continues to provide our region with valuable water information.

Gauging the value of stream gages

For almost 100 years, communities along the Great Miami River have been protected by a system of dams and levees built by MCD. The system is an engineering masterpiece.

Since their completion in 1922, the dams and levees have protected riverfront communities from Piqua to Hamilton with a 100 percent success rate! To maintain and properly operate this system, MCD needs accurate and up-to-date information about river levels and how weather will impact the Great Miami River and its tributaries.

Stream gage at Franklin – The gage is mounted to the side of a bridge over the Great Miami River. The gage uses a radar sensor to measure the distance to the water surface below.

Stream gage at Franklin – The gage is mounted to the side of a bridge over the Great Miami River. The gage uses a radar sensor to measure the distance to the water surface below.

MCD and United States Geological Survey (USGS) collect information at 25 locations along the river. Each location features a stream gage that collects river flow information. These stream gages are part of a national network of stream gages maintained by USGS. Stream gages are located along the Great Miami River in most of the cities MCD protects.

The gages transmit hourly information on the amount of water in the river channel (elevation or height of water surface in the river). MCD staff uses information from the stream gages during high water events to determine when to close flood gates, measure groundwater levels beneath levees, and inspect levees for signs of erosion or underseepage caused by high river levels. MCD’s stream gage information also is used by the National Weather Service, recreationalists, and businesses and contractors working near or in the river channel.

MCD floodgate in Miamisburg - The wheel at the top of the concrete box closes the floodgate below to prevent river water from flowing into the landward side of the levee.

MCD floodgate in Miamisburg – The wheel at the top of the concrete box closes the floodgate below to prevent river water from flowing into the landward side of the levee.

Closing flood gates is one of the most important tasks MCD staff does during a high water event. Floodgates are normally left open so that runoff from city streets and parking lots can flow through the levee and into the river. When the river rises high enough, however, water can flow backwards through the floodgate and into city streets, threatening to flood areas protected by the levee. MCD staff close floodgates to prevent this from happening, and timing is critical.

The National Weather Service’s Advanced Hydrologic Prediction Service (AHPS) uses MCD’s stream gage information – along with other vital data – for its daily river forecasts, which are available online. AHPS incorporates information from stream gages and weather forecasts into models that predict future river flows. River forecasts wouldn’t be possible without stream gages.

Timely river forecasts allow MCD to plan ahead and take actions necessary to prevent communities from flooding. Knowing current and predicted river levels is integral to operating MCD’s flood protection system.

Our region is fortunate to have a stream gage network that provides this critical information. In a future blog I’ll talk more about how stream gages work.

Globally, a record warm June; locally, a very wet June

By Mike Ekberg
Water Resources Manager

According to the National Oceanic and Atmospheric Administration (NOAA), June 2015 was the warmest June ever from a global perspective. The combined average temperature over global land and ocean surfaces was the highest ever measured for the 136 years in which records have been kept. The combined average temperature across the world’s land and ocean surfaces was 0.88 °F above the 20th century average.

In fact, the first six months of 2015 comprised the warmest six-month period on record across global land and ocean surfaces at 1.53°F above the 20th century average. This might seem surprising to Miami Valley residents because we experienced cooler than normal temperatures. The first six months of 2015 were cooler than normal across most of eastern North America, probably due to several southern invasions of the polar vortex which brought cold arctic air into eastern portions of Canada and the United States during the winter of 2015.

In addition to tracking temperature, NOAA also tracks precipitation globally. Precipitation in June was highly variable, but much of eastern North America received precipitation in the normal to twice-the-normal range for the month. The Ohio River Valley, the eastern portion of the Lake Erie Basin, and the Mississippi River Valley in Illinois and Iowa were particularly wet. Much of this region received 5 to more than 10 inches of precipitation in June. Flooding occurred throughout portions of northwest Ohio, northern Indiana, and Illinois.

MCD tracks precipitation in the Great Miami River Watershed. MCD’s records show June was a very wet month in the Miami Valley as well.

  • Monthly precipitation at MCD observer stations ranged from 5.60 inches at West Milton to 11.61 inches at Fort Loramie.
  • Mean precipitation for the Great Miami River Watershed was a little more than 8 inches, twice as much as we would normally expect in June.
  • Runoff for the Great Miami River measured at Hamilton was a little over 3 inches, three times the normal amount of runoff in June.
  • MCD dams stored water on two occasions in June.

Despite these numbers, June was not a record-setter locally. The wettest June on record occurred in 1958, when an average of 10.30 inches of precipitation fell across the watershed.