MCD has its eye on water

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

Did you know MCD tracks precipitation, groundwater levels, and flow in rivers and streams?

This information helps MCD and its partner agencies with flood forecasting, groundwater quantity monitoring, and understanding water movement into and out of the Great Miami River Watershed.

Here’s what we tracked in 2016 and what we’ve seen in 2017.

Water in 2016

  • Precipitation for the year was right around 37 inches or about 2.5 trillion gallons of water.
    • Average annual precipitation for the Miami Valley is about 43 inches.
  • Precipitation was below average eight of 12 months in 2016.
    • August was a notable exception with nearly 6 inches of rain. The average for that month is a little more than 3 inches.
  • Runoff from the Great Miami River Watershed into the Ohio River was about 12 inches or 823 billion gallons of water. Runoff includes water from rainfall and groundwater water that seeps into the river.
    • Average annual runoff is about 15 inches.
  • Water levels in the buried valley aquifer began the year near average at most observation wells. They declined to below-average levels during the summer and then returned to average levels in the fall.
  • Water recharge to Miami Valley aquifers averaged a little more than 6 inches or about 411 billion gallons.
    • Average annual recharge for the watershed is around 8 inches. Despite the lower average for 2016, the region has an abundance of groundwater.

What are we seeing in 2017?

We’re not even halfway through the year, and precipitation and runoff are trending above average. At the end of May, MCD had recorded nine high water events this year, which is above average for the entire year. MCD recorded only five high water events during all of 2016.

MCD defines a high water event as a time when:

  • Any single dam goes into storage, meaning the elevation of the water upstream of the dam exceeds the top of the dam’s conduit.
  • Or the river at any of our cities reaches an “action stage” as defined by the MCD Emergency Action Plan, such as closing a floodgate.

All of the dams except Huffman Dam have stored floodwaters at least once this year:

  • Germantown Dam – 7 storage events
  • Englewood Dam – 9 storage events
  • Lockington Dam – 1 storage event
  • Taylorsville Dam – 1 storage event

According to the National Oceanic and Atmospheric Administration’s Ohio River Forecast Center, there’s an equal chance of above- or below-average precipitation for the next three months. Beyond that, it’s anyone’s guess.

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.

Good news/bad news: Water use declining in our region

By Mike Ekberg, Water Resources Manager

Water use declined in the Great Miami River Watershed by 50 percent between 2005 and 2013, which mirrors a national trend.* With the dire predictions for water shortages in other parts of the world, this may seem like good news for our region, but there are consequences.

Great Miami River Watershed map

Great Miami River Watershed: All of the land in green drains to the Great Miami River.

The good news is that we are wasting less water and using it more efficiently in industrial, commercial and agriculture processes. Having plenty of water means this region is better prepared for future unpredictable weather patterns.

Declines in water use, however, also happen when industries or businesses close or move out of the region. Decreased water use could mean there is less demand for water. Less demand means fewer water customers.

Most water utilities have rate structures that charge customers based upon the amount of water used. As customers use more water, revenues increase. But fewer customers don’t translate into fewer expenses because the same amount of infrastructure is required to deliver the water to users.

Some water industry experts refer to this trend as the ‘conservation conundrum’ where declining water demand creates significant financial challenges for water utilities that are faced with rising costs to maintain and repair aging infrastructure. These costs must be recovered from a shrinking customer base.

Water Use in the Great Miami River Watershed

In 2005, total water use in the region was 580 million gallons of water per day. By 2013, water use declined to just over 290 million gallons per day.

Water uses in Ohio are grouped into seven categories: public drinking water, golf course irrigation, power generation, agricultural use, industry, mineral extraction, and miscellaneous uses. From 2005 to 2013, use of water in our region declined in most categories.

Water use statistics from ODNR Water Withdrawal Facilities Registration database

Water use statistics from ODNR Water Withdrawal Facilities Registration database

According to a recent report by the United States Geological Survey (USGS), public drinking water use declined by 5 percent nationally from 2005 to 2010. In our region, it declined by 15 percent, from 2005 to 2013.

Locally, power generation saw the greatest decrease in water use. Water used for power generation declined by 90 percent over the eight-year time period. Most of this reduction came from the decommissioning of Dayton Power & Light’s Hutchins Power Station.  Water used for mineral extraction and for industrial production declined by 69 percent and 55 percent, respectively. The only significant increase in water use occurred in agriculture (15 percent).

Water Use Nationally

Water use statistics in the Great Miami River Watershed mirror a national trend of declining water use. Water use in the United States was at 355 billion gallons of water per day in 2010. This was the lowest water use in the United States has been since the 1960s.

The reduction likely is due to several reasons, including industry’s efforts to conserve water to reduce expenses, a shift from coal (which uses a lot of water) to more energy-efficient fuels, and the increase of energy efficient appliances in homes.

Looking Ahead

Given the statistics, our region isn’t expected to face water shortages anytime soon. This is an opportunity to attract additional responsible water users to our region. The challenge for water utility managers in this area will be to figure out how to generate sufficient revenue to maintain and improve existing infrastructure in a world that will continue to become more water efficient. This may require rethinking traditional business models and rate structures.

*Even California, which is in a serious drought, has seen reduced water usage. The challenge in California is that despite conservation efforts, the state still uses more water than it receives from rain and snow.