Ellicott City a Poster Child for Denial, Ignorance, Arrogance, and Greed

May 28, 2018

Here in mid-Michigan we spent yesterday without power following unusually violent, (for this area) thunderstorms on Saturday night.  Other parts of the Eastern US got pounded as well. More on the way.

As soon as I saw the images coming out of Ellicott City, Maryland last night, I flashed on the opening to this two year old video, above, which is footage from that city’s last “1000 Year Flood”.


In the first 30 seconds, you’ll hear horrified customers in an upper floor eatery gasping at the unfolding disaster in the street, and a blood curdling emergency buzzer going off.

In the tweeted vids below from yesterday, you hear the same alarm going off in the background.
Pretty good metaphor, as the planet’s warning bell continues to sound, unheeded.

Important subtext.
This kind of flooding is not just about climate change, although clearly the record breaking rains were what set the disaster off.
Importantly, arrogance and ignorance in land management upstream was an amplifier, and will continue to be, until local officials and developers recognize that water has no political agenda, it just flows down hill – and wetlands are not just nice things for flora and fauna – they are critical natural buffers against just this kind of event.
More below:

Marshall Shephard is former President of the American Meteorological Society. He has a take in Forbes:

If you didn’t see the floods in Maryland this weekend, they were “OMG” and “what the heck is going on” bad.  In Ellicott City, Maryland, a suburb west of Baltimore, 5.52 inches of rain fell over a 90-minute period according to the National Weather Service (NWS). Nearly half (3.16 in) of the storm’s total rainfall (6.50 in) fell in the first 30 minutes. As predictable as the sunrise, there will be the usual banter by the “what is the role of climate change” crowd and the “floods always happened” crowd. I review some of the current science of extreme rainfall — climate change attribution — but that is not my point herein. My goal is to discuss two overlooked ways human-activity affect these floods: urban impervious surface and storm water management systems.

Preliminary analysis from the NWS finds rainfall rates in this event had about a 0.1% chance of happening in a given year. This is would be characterized as a ‘1,000-year event’, which I explain here. At the 2016 American Meteorological Society’s Summer Community meeting on water, experts urged the community and media to move away from that explanation because it is confusing to the public. I agree. Several ‘1,000-year events’ could happen this year, the likelihood is just very low.

Is it perception, or are we seeing different types of rainstorms now? What does the science say? Meteorologist Sean Sublette of Climate Central said in an email,

According to the 2014 National Climate Assessment (NCA), there was an increase of 71% in the amount of precipitation in the heaviest events in the Northeast (including Maryland) between 1958 and 2012.


An analysis (below) adapted from the work of Dr. Ken Kunkel and colleagues shows that the “once-in-five-year” event (defined as two-day precipitation total that is exceeded on average only once in a five-year period) has increased in recent decades relative to the period 1901-1960 (Note: the 2000s decade includes 2001-2012).


The most comprehensive report to date on attribution of extreme weather events to climate change was published this spring by the National Academy of Science. The report states,

Confidence in attribution analyses of specific extreme events is highest for extreme heat and cold events, followed by hydrological drought and heavy precipitation………


As I noted in a previous Forbes piece summarizing the report,

There is good physical understanding of how the warming aspects might lead to greater evaporation rates (to further amplify a drought or make more water vapor available in a precipitating storm). There was only moderate confidence in the length of record and ability of model to simulate other aspects…….There is emerging literature that may increase our confidence going forward, but the body of literature does not support a higher confidence rating at this time.

I often state that urban flooding witnessed in Maryland this weekend boils down to a simple equation:

Urban Flooding = Increase in intensity of top 1% rain events + expanding urban impervious land cover + storm water management engineered for rainstorms of “last century”


Urban land cover change in the Baltimore-Washington DC area through 1992. Source: USGS – Click for larger

The Maryland floods were caused by slowly moving thunderstorms in the region. In 2016 rainfall is increasingly falling onto more urbanized, impervious surfaces. More asphalt and concrete increases the rate of runoff into streams, rivers, and lakes while reducing infiltration into the ground. Think back to your 4th grade lesson about the water cycle. For the first time in history more people live in urban spaces than rural spaces. As I stated in our 2011 study of the Atlanta flood of 2009,

“(studies) found that impervious surfaces in Houston (and other cities) distributed storm water to conveyance systems with more volume over a shorter time, which increases the risk of overwhelming the capacity of the system”

I believe the Ellicott City, Maryland flood is a textbook example as the Patapsco River rose 13 feet within a few hours, according to reports.

Hydrologists and civil engineers use statistical understanding of frequency and intensity of occurrence of heavy rainfall events (best represented as Intensity-Duration-Frequency curves) in the engineering considerations of urban storm water management and drainage. Many peer-reviewed literature studies affirm that storm water engineering for some cities may designed for last century’s rainfall rates (i.e., the assumption of stationarity or that 1950s rainstorms are just like 2016 rainstorms). Study after study increasingly recommend updated rainfall-IDF relationships in the design of new or updated drainage systems because contemporary rainstorms are overwhelming the system.

As we continue to watch extreme urban flooding around the nation, keep in mind that these events are not just a function of what is falling from the sky.

16 Responses to “Ellicott City a Poster Child for Denial, Ignorance, Arrogance, and Greed”

  1. dumboldguy Says:

    One of your best posts ever, and likewise for the opening video you did two years ago.

    I have visited Ellicott City more than once—-it’s a neat 250-year-old “touristy” kind of place with lots of neat shops and a railroad station museum. They had just about finished rebuilding Main Street and were hoping for a good summer tourist season.

    It has flooded in the past, usually from hurricanes, but this “6 to 8 inches of rain in a few hours” thing is something new. And yes, it’s the development on the high ground above the town that has exacerbated the problem by increasing rapid runoff.

    We in NO VA west of DC have been living with weather more akin to the Pacific Northwest for weeks now. So much rain and for so long that we haven’t been able to mow our lawns and the nightly weather is constantly nattering about “flash flood warnings” and “do not drive into into moving water”. None of our local meteorologists have yet mentioned climate change as it impacts our weather—-the folks in other cities have it better, Phoenix especially—-Amber Sullins is smart, committed, and honest (and nice to look at)

    • Lionel Smith Says:

      We had a a few hours of similar weather over here in the UK late Saturday evening. Started around 2300 with a few faintly seen flashes through the bedroom curtains. Watching for a few minutes as flash came on flash with barely a pause I was up and about powering down and disconnecting sensitive kit. Went out the back for a few minutes and seeing simultaneous flashes from four or five areas in the sky with more coming immediately I knew this was something I had not seen in my seventy odd years, except in Fort Lauderdale in June 71 when visiting thanks to the Grey Funnel line, but even there the flashes were distinctly separated in time. Reports the next day of 1500 to 20000 strikes across Southern Britain in four hours.

      Then the rain came. Flash floods now a common feature in ol’ Blighty.

  2. grindupbaker Says:

    Joi-Marie “Praying for all the shops and homes on Main Street”. Praying should do the job all right. I’m pretty sure actuaries have proved this. Keep up the good work.

  3. Gingerbaker Says:

    Is it possible that “Ellicott City a Poster Child for Denial, Ignorance, Arrogance, and Greed” is a little harsh?

    One gets the feeling that a lot of places that never considered flash flood control are going to be forced to deal with it. This stuff just doesn’t happen until it happens. When it happens again, people start to figure it out.

    I am a sucker for watching youtube disaster video. I find it incredibly compelling. Tsunamis, rockslides, etc. While a lot of the world lives in places that would totally creep me out – really steep mountainsides, I can tell you from these videos that most people have no idea how much danger they are in.

    The combination of steep hillsides and drenching rain is starting to freak me out a bit. Lush farmland in Italy is not all that different than Vermont, and there is some scary footage on youtube of Italian landslides caused by oversaturated soils. Huge hillsides slowly pouring like butter. And, yeah, we live toward the bottom of a pretty big hillside.

    • dumboldguy Says:

      Yeah, it may be a bit harsh for the people on Main Street who lost so much, although they are in denial for thinking it wouldn’t happen again for another 1000 years.

      But the whole Bos-Wash corridor (which is becoming Bos-Wash-Rich because of the urban sprawl spreading south out of DC to Richmond, VA) is a poster child for “denial-arrogance-ignorance-greed”. Minimansions, apartment and condo blocks, warehouses, retail, roads, and parking lots being built everywhere. See the Oh Deer Me clip in the post to get a taste. OLD Ellicott City sits in a ravine below NEW Ellicott City, and all the development up top has made it worse, although that much rain in that short a time would be almost impossible to deal with anyway.

      Don’t think you have too much to worry about re: your house being buried—-most slides in VT seem to be at road cuts—-check this out.

      Click to access report.pdf

  4. ted knopper Says:

    Looked up the FEMA maps on the city. The old town is built right at the intersection of two large rivers or streams which drain a rather large area. It has always had flood problems due entirely to its location. That is why it flooded, it floods in every large rain storm. They need to move that city uphill. Here is the map.


    • dumboldguy Says:

      No, Knopthead, it is NOT built at the “intersection of two large rivers or streams which etc”. I am not surprised to see that map reading is not in your skill set either, and that you continue to spout expertise based NOT on having been there, but on some googled crap that you don’t even understand.

      The several small streams that come together and course down parallel to Main Street are normally not much more than a drainage ditch. several feet below the level of the streets and not even knee deep. The Patapsco River that they flow into is BELOW the Old Town, and only backs up into the lower part a bit during big floods.

      The nearest airport is BWI—-fly in, rent a car, and see for yourself.

      As for “They need to move that city uphill”? DOUBLE-DUH. Again, I suggest that you find a job appropriate to your abilities—doorstop or paperweight—and leave us alone on Crock

  5. rhymeswithgoalie Says:

    It usually takes deaths to change policy. Thirteen people died in Austin’s 1981 Shoal Creek flood, leading to significant changes to building restrictions and requirements and the construction of greenspace flood basins. I remember arriving here in 1991 wondering about those giant dry concrete pits by parking lots, and how some of the parks were sunk lower than the surrounding roads and houses. I have since seen how quickly heavy thunderstorms can fill them.

    Now when I see videos of flooding reaching the tops of concrete picnic tables along river banks or creeks I recognize this as deliberate and useful design at work.

  6. fjohnx Says:

    Missing forests and wetlands are the twin amplifiers of these disasters.

  7. Peter Scheffler Says:

    When I took a course in floodplain management long ago we looked at statistics for precipitation, and I realized that extreme events like the 1% chance rainfall seemed to cluster, with several occurring within a few years, rather than being more evenly spread out over time.

  8. redskylite Says:

    Another shock with images that are becoming so numerous and common in this era, how much was due to climate change remains to be worked out, but certainly it was supercharged by climate change on top of every thing else. A very fair discussion by the weather gang in the Washington Post today.

    “Ruined once more, Ellicott City endured an hours-long cloudburst that drowned the town Sunday. To witness this disaster unfold again, less than two years after the previous flood catastrophe, is nearly unthinkable. Call it Flood City, USA, for a location that has flooded 15 times, at the hand of storms, since 1768.

    A waterlogged weather pattern, Ellicott City’s flood-prone geography and climate change all conspired to make this latest flash-flood horror show.

    Is this climate change?

    Yes and no. This was an extremely localized, small, relatively short-lived storm. Climate change unfolds on time scales of decades and over very large regions, by comparison. Climate change did not “cause” this thunderstorm complex.

    However, climate change has probably altered the larger environment in which these small thunderstorms are embedded. Notably, the water vapor content of the atmosphere, as a whole, has increased and scientific studies have shown a statistically meaningful uptick in the frequency of extreme rain events over the eastern United States. Statistically, over the long term, these types of extreme floods are probably becoming more common, in areas that are normally rainy as a result of global warming.”


    • dumboldguy Says:

      No, the WashPost did not cover itself with glory covering this one. See my first comment and look up what recently happened in Frederick, MD, not too far to the west of Ellicott City. More stalled weather, downpours, flooding—–we in the Mid-Atlantic are experiencing the predicted crazy and extreme weather—-everywhere!

      Even though Chris Mooney and other good science writers are on staff, they are not covering climate change quite the way they used to—-is Bezos telling them to tone it down because he doesn’t want to hurt Amazon?

      And the WashPost actually had a column today saying how wonderful small business people were and we should all help them rebuild again on the SAME street that has had two 1000-year floods in two years.

  9. redskylite Says:

    Forewarned is forearmed

    1. proverb
    prior knowledge of possible dangers or problems gives one a tactical advantage.

    From the 2016 flooding a telling story from the Baltimore Sun’s archives:

    From the archives: After deadly flash flood, concern about development’s impact on Ellicott City.

    “Twice in five years, Ellicott City has flooded when two small streams that eventually feed into the Patapsco overflowed. Water rushing down Main Street crushed stone walls and destroyed roads, cars, homes and businesses. In the latest calamity two weeks ago, two people died.

    Developers have submitted more than 100 proposals to build homes, shopping centers and other buildings in less than 3 square miles around Ellicott City since 2001, and most applications have been approved. Dozens of those developments are near the Tiber and Hudson streams that overflowed.

    Howard County officials insist that development by itself cannot be blamed for a dramatic act of nature, but they and residents believe the devastating floods in July and another in 2011 send a clear message: Heavy rains will come again, and something must change.
    “climate change could make future flooding more frequent and larger in scope.”


    • redskylite Says:

      Meanwhile in Germany

      After the massive rainfall, the city is ruled by « obviously the state of emergency, »said the fire department in the late evening. More than 500 missions were therefore still pending. The fire department Wuppertal submitted to the fire department Essen an official request for help. The German railway and the Wuppertal suspension railway, the landmark of the city, therefore stopped the local operation.

      Hundreds of firefighters were also reported from other parts of North Rhine-Westphalia for overflowing streams, flooded streets and cellars. 19659004] Thunderstorms continue


    • redskylite Says:

      Meanwhile in India

      At least 50 people are reported to have died amid heavy thunder and lightning that battered parts of northern India on Tuesday, officials said.

      High-speed winds and lighting strikes devastated many villages, bringing down walls and leaving dozens injured.

      The eastern state of Bihar was the worst hit, with 20 confirmed deaths due to lightning.

      The latest incidents come weeks after devastating dust storms killed more than 100 people across north India.


  10. Abel Adamski Says:

    There are floods and extreme weather world wide.
    In case you don’t have the link

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: