More than 4 feet of precipitation in 2018!

By Mike Ekberg, manager of water resources monitoring and analysis

One year ago, I wrote a blogpost summarizing the year 2017 as “another wet year.”

Now I’m summarizing water conditions for 2018, and I could pretty much copy and paste what I posted last year. And, with some minor changes, it would ring true. Last year reflects a continuation of the trend in rising precipitation for our region. If it continues, we’ll see more rain, more runoff, and more high-water events in the future.

The chart below shows how the 30-year average annual precipitation for the Great Miami River has changed since 1945. Note the upward trend in precipitation that began sometime around the late 1980s to early 1990s.

Noteworthy Weather
Significant weather events in 2018 included record high precipitation in February, a large high-water event in April, significant showers and thunderstorms in August, the remnants of Tropical Storm Gordon in September, a much warmer-than-normal October, and a cold and very wet November.

Precipitation for 2018 was much above average for the Great Miami River Watershed at 50.68 inches. This is 10 inches above the 30-year average annual precipitation of 40.30 inches. The Miami Conservancy District (MCD) observation station in Dayton recorded 48.70 inches of precipitation in 2018, which is the sixth highest since record-keeping began in 1883.

Monthly precipitation was more than 1 inch above average in February, April, August, September, and November. May, July, and October were the dry months, recording more than 1 inch below-average precipitation. February set an all-time record high for the month with an average of 5.35 inches of precipitation for the Great Miami River Watershed.

The chart represents an average of 42 precipitation stations MCD operates.

Three High Water Events in the Top 100
The greater-than-average amounts of precipitation in 2018 led to above-average runoff. Runoff is that portion of precipitation which flows downhill or seeps into aquifers, and enters streams, rivers, lakes or ponds. Runoff in the Great Miami River Watershed ultimately ends up in the Great Miami River. Annual runoff for the Great Miami River was 23.26 inches in 2018, which is 8.69 inches above average. MCD recorded 13 high-water events last year – well above the average of eight. A high-water event is defined by MCD as a time when one or more of the following occurs:

  • Any one dam goes into storage – when the conduits slow the flow of water. This is approximately when the conduits are flowing full.
  • The river at any one of the cities we protect reaches an action stage as defined by MCD’s Emergency Action plan.

The largest high-water event in 2018 took place from April 3-9 and resulted in a total peak storage of 65,050 acre-feet (21.2 billion gallons) of water behind all five MCD dams. This event ranked as the 12th largest high-water event in MCD history. MCD also recorded its 49th and 55th largest events in 2018.

There is evidence that rising global temperatures are increasing the amount of water or humidity in the atmosphere. Satellites have measured a 4-percent rise in water vapor in the air column. The more humid atmosphere seems to be making storms wetter. Many weather stations in the United States are showing increases in extreme precipitation. Our region seems to be showing signs of this trend.

 

 

Green development could mean green backs for your community

By Sarah Hippensteel Hall, Ph.D., manager of watershed partnerships

Could your land use plan be holding back your community?

It could if you’re not focusing on balancing water protection with land development.

This region is averaging about 4 more inches of precipitation per year than it did 30 years ago. Stronger storms, heavier rainfalls and destructive erosion are becoming more common. Just a few weeks ago, the region experienced a new record for rainfall for June 14, from 1.29 inches that day to 2.68 inches, according to a Dayton Daily News story.

This region now averages about 4 more inches of precipitation per year than it did 30 years ago.

Businesses looking to grow or relocate want to be sure flooding isn’t an issue. Communities now more than ever need to focus on protecting their water, and mitigating flooding and peak flows.

Studies show green development practices can save money 

According to a 2010 study by the American Society of Landscape Architects, governments are wasting billions of dollars a year by not going green. The report looked at 479 case studies of green development projects around the U.S. and found that in more than 73 percent of the cases, the environmentally friendly solution cost the same or less than traditional development.
According to the study, green development practices:

  • Not only cost less, but these practices can further reduce costs of treating large amounts of polluted runoff.
  • Can help municipalities reduce energy expenses.
  • May reduce flooding and related flood damage.
  • Improve public health — reducing bacteria and pollution in rivers and streams, preventing gastrointestinal illnesses in swimmers and boaters.

Seattle Public Utilities found that using grassed channels; combined with narrowing the roadway, eliminating traditional curb and gutter, and placing sidewalks on only one side of the street garnered a cost savings for the city of 15–25 percent, or $100,000 – $235,000 per block, as compared to conventional stormwater control design (Center for Neighborhood Technology, 2010).

One study found that using green development practices saved 15 to 20 percent in stormwater control costs.

 

Land Use Planning to protect water and maximize economic opportunity

MCD can help communities that want to integrate water protection into their land use plans, zoning code, and subdivision regulations. Amending local codes and ordinances is an important first step to achieving a balance between protecting water and promoting economic development.

Communities often find that their existing development policies conflict with the goal of water protection. For instance, current design calls for

  • Wide streets
  • Expansive parking lots
  • Large-lot subdivisions

Massive parking lots are impenetrable, creating a barrier to groundwater recharge.

All of these create excessive impervious cover, increase flood risk in low lying areas, and provide little room for green space and a natural environment. Incentives for developers to conserve natural areas and consider water protection are generally few and far between.

So what’s the answer?

Better Site Design is an approach to both residential and commercial development that is intended to:

  • Reduce flood risk.
  • Help comply with stormwater regulations.
  • Increase groundwater recharge.
  • Improve stormwater filtration.
  • Reduce erosive flows to streams and rivers.

All of the above can save your community money and create a more marketable product.

Pervious pavers like this driveway in Brookville reduce stormwater runoff and last years longer than concrete. 

How MCD can help

Using a Site Planning Roundtable, MCD staff can guide a community through a consensus process, bringing together local leaders from government, development, and natural resources.

Together, we’ll create development policies that balance water protection and economic development for your community.

The local roundtable will:

  • Identify existing development rules.
  • Compare them to the principles of Better Site Design.
  • Determine if changes can or should be made to current codes and ordinances.
  • Negotiate and reach consensus on what the changes should be.

Let’s get started!

MCD, in partnership with local sponsors, can assist communities during all phases of the Site Planning Roundtable. Call me at 937-223-1278 ext. 3244 and let’s get started!

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.

Region’s water levels more stable than other parts of the U.S.

By Mike Ekberg, MCD water resources manager

Stories about droughts, water shortages, and aquifers drying up are in the news with regularity these days, especially in places throughout the western United States.

What are the chances that our aquifer could run dry? Are the water levels in the Great Miami River Watershed and its buried valley aquifer increasing, declining or staying the same?

According to the measurements taken by MCD over the last 30 years, the water supplies in the Great Miami River (GMR) Watershed are in what’s called a steady state. That means the amount of water that flows into and out of the watershed – the 4,000 square miles of land that drain to the Great Miami River – is relatively constant over the last 30 years.

2014 Great Miami River Watershed precipitation totals

2014 Great Miami River Watershed precipitation totals

In 2014, the Great Miami River Watershed received 39.05 inches of rain and snowmelt (inflows) – which matches the long-term average. That amount of water equals 2.7 trillion gallons of water.

Water leaving the region through evaporation and plant uptake (outflows) averages about 26 inches or nearly 1.8 trillion gallons.

On average, another 900 billion gallons of water flows into the Great Miami River through runoff each year. Runoff is water that flows over the land (overland flows), runs through soils (interflow) and into the aquifers (groundwater flow).

That’s 2.7 million gallons into the watershed and another 2.7 million gallons out of the watershed.

Groundwater levels in aquifer

Graph shows seasonal fluctuations in the depth to groundwater. Over the last 30 years, there is no upward or downward trend.

There are fluctuations in water levels year to year, but over the long term, precipitation and runoff balance each other out, leaving the total amount of water stored in the Great Miami River Watershed essentially the same.

Another factor in water usage is human use. The Ohio Department of Natural Resources says people use about 124 billion gallons of water per year, mostly for public water supply, industry, and cooling water for power generation. Most of that water returns to the Great Miami River Watershed through municipal sewer and industrial wastewater treatment plants. Of the 124 billion gallons of water used by people, MCD estimates only about 23 billion gallons of water is actually consumed or removed from the watershed before it reaches the Great Miami River. Although 23 billion gallons of water sounds like a huge quantity, it’s only a small amount when compared with the 2.7 trillion gallons that enter and exit the watershed each year.

While our water levels are steady today, that’s no guarantee for the future. Changing weather patterns and increasing water uses by people are unknown. That’s why it’s critical to track water over time and why MCD measures precipitation and river flows throughout the watershed using a network of gages.

Keeping an eye on water levels is vital to detecting trends so that policies and programs can safeguard our water supplies.