flooding

Smart Phone Flood Mapping Takes Next Steps

Second Year of Crowdsourcing Flooding Data

Second Year of Crowdsourcing Flooding Data

SNAPSHOT: In 2017, Wetlands Watch and its partners held a regional event to crowdsource flooding information, using the highest projected tide of the year (the so-called King Tide) as day of the event. We did it again in 2018 with new partners and an expanded focus. Now we are running the mapping year around, with neighborhood teams being organized across Southeast Virginia.

BACKSTORY: In 2014 we developed a smart phone app that allowed people to map where it flooded in their community allowing them to take an active role in adaptation and flooding solutions. The app, “Sea Level Rise,” caught the attention of the environmental reporter for the Virginian Pilot, Dave Mayfield, who convinced his editors to sponsor a regional crowdsourcing event to collect flooding data around the “King Tide,” the highest of the fall perigean tides. The event was a success with over 700 mappers out mapping at the same time! So many in fact that we have applied for a Guinness World Record designation.

So we did it again in 2018, this time with new partners at WHRO, the regional NPR affiliate. They developed lesson plans that meet state standards and received a grant to enroll over 120 high school classes in a year-long mapping effort. The 2017 effort brought out over 400 mappers, many of whom wanted to continue to map outside of the King Tide event.

This is music to the ears of Dr. Derek Loftis, a researcher at the Virginia Institute of Marine Science who is using this mapping data to perfect his flooding models. He has been the primary user of the flooding data collected by these events but needs data collected at different times and in different areas.

So now we are looking for funding to keep the work going year around, with mapping teams being organized across Hampton Roads.

City Says "No" to Development Because of Flood Risk - First of a Kind!

Road Near Proposed Development - Virginian Pilot/Ron Stubbins photo

Road Near Proposed Development - Virginian Pilot/Ron Stubbins photo

For the first time that we can find, a local government has said "no" to a development proposal due to flood risk. The City of Virginia Beach, hammered by increasing rainfall, has been more sensitive to the flooding potential, especially in the low-lying southern part of the City. But lots of localities are concerned about and planning for flooding, but still allow people to develop in dangerous places.

No more in Virginia Beach. The City Council unanimously denied a proposed 23-home subdivision on a soggy piece of land because of concerns about flood risk and future city liability. Recently burned by the flooding in a recently constructed subdivision, Ashville Park, Virginia Beach Planning Commission and City Council members expressed doubts about this proposal. Even though it met the technical requirements, the access roads flood frequently, flooding will increase, and the city did not want to put more people in harm's way.

This follows on the City's work to document the increased rain flooding risk that is equally important and groundbreaking.

Stay tuned for lawsuits and negotiations, but for now the City of Virginia Beach is the first in the country to say "no" to soggy development proposals.

Study Confirms What We Are Seeing - Nuisance Flooding is Increasing/Will Continue to Increase

Porjections of flood days per year, from NOAA Study

Porjections of flood days per year, from NOAA Study

SNAPSHOT: A new study from NOAA projects increases in high tide flooding onto streets and sidewalks in shoreline communities. These floods will occur every other day - possibly every day - by 2100 even using very conservative sea level rise estimates. Given the time and money required to mitigate the damage from this constant flooding, we need to start yesterday to put adaptation measures in place.

BACKSTORY: Anecdotally, Wetlands Watch has been hearing for years that tidal water levels seem to be increasing. At community meetings and service club talks, we heard more complaints that tidal waters were lapping over roads and sidewalks and coming up out of stormwater pipes and ditches. We observed changes in rural ditches in Mathews County, ditches that were dry when we started working up there in 2008 and now are full of water most days and have tidal wetlands plants growing in them. We have documented this nuisance flooding in urban areas.

Projections for Downtown Norfolk, VA by Dr's. Tal Ezer and Larry Atkinson of Old Dominion University.

Projections for Downtown Norfolk, VA by Dr's. Tal Ezer and Larry Atkinson of Old Dominion University.

In the graph above, two oceanographers from Old Dominion University in Virginia developed projections of future nuisance flood risk. The blue in the graph is the observed flooding (hours per year) since the tide gauge at the Norfolk Naval Station was put into service in 1927. The green bars in the graph are the projected flooding hours/year with the current rate of sea level rise. The red bars are the projected flooding hours/year with the accelerated rate of sea level rise we are seeing, about twice the current rate.

Solutions? Start today with detailed maps of where flooding will occur. Take extra precautions to build "freeboard" or additional flood protection into local land use actions or federal investments along the coast. Start developing comprehensive plans among all the stakeholders - public and private - to address the flooding.

Oh, and we need to start stacking up the dollar bills needed to pay for all the work we have to do.

Regional Citizen Science Effort Grows - "Measure the Muck" Added

Measure the Muck logo

Measure the Muck logo

Snapshot: While we're out measuring the extent of the flooding, a team will also be measuring the pollution being washed off the land by that flooding.

Backstory: Southeast Virginia/Hampton Roads is embarking on one of the largest citizen science efforts ever with it's King Tide mapping event. Now, another effort has been added, "Measure the Muck."

This new effort is the brainchild of Dr. Margaret Mulolland of Old Dominion University, who does a lot of work on harmful algal blooms. While most folks here worry about where the water goes when it tops the bank, she wonders what it brings back with it when it recedes. She suspects that these flooding events bring a load of nutrients and bacteria into our rivers and bays, providing the fuel for algal blooms. Controlling this loading would help manage these algal blooms but no one has measured the amount of nutrients and bacteria being washed from the land.

So a group of volunteers will go out on Nov 5 with field kits for collecting water samples around stormwater outfalls that will later be tested (thanks to the Hampton Roads Sanitation District for providing the funding).

Wetlands Watch's interest in this (other than the fact that Dr. Mulholland is our executive director's spouse!) is to explore the co-benefits of nature based solutions to stormwater and flood management. If the areas that flood are also significant sources of pollution, we can better target our efforts and use one dollar to fix two problems.


Oct 21 Sea Level Rise app test

Oct 21 Sea Level Rise app test

We've got some volunteers signed up for "Measure the Muck," 28 people so far. As shown above, on a sunny Saturday, Oct. 21, a group of Old Dominion University students together with a bunch of Maury High School students tested the app in preparation for the stormwater pollution measurement citizen science effort.

UPDATE

Measure the Muck sampling crew getting trained as the water seeps underfoot.

Measure the Muck sampling crew getting trained as the water seeps underfoot.

On the day of the flooding event, the Muck teams were assembled and given sampling equipment. The teams of students fanned out across Norfolk along the Layfayette River watershed to take samples from flooded areas.

Muck team samples flood waters in Norfolk - Maury High School and Old Dominion University Students (and even a 7th grader in the foreground taking the sample!)

Muck team samples flood waters in Norfolk - Maury High School and Old Dominion University Students (and even a 7th grader in the foreground taking the sample!)

While the samples are still being analyzed, early results are showing high levels of pollution. Most of the bacteria samples had concentrations so dense they were beyond the ability of the lab equipment to measure it!

Fall Storms Bring Flooding to SE Virginia

The impact of four feet of flooding on Hampton Boulevard, the major N/S road in west Norfolk. This is one of two roads leading Naval Station Norfok.

Jose and Maria are messing with Southeast Virginia. The video above is Hampton Boulevard in Norfolk, VA during the run up to the high tides on September 19, 2017, from Jose. On Sept 26 and 27 another set of high tides is hitting. At least these "modest" floods help us find all the areas that flood so we can put them on the map.

We are also in the midst of a major regional, crowdsource flood mapping effort around the hugest projected tide on November 5, 2017, the so-called "King Tide" of the year. We've been holding mapping trainings leading up to that event.

During the Jose floods I was out in the water doing some mapping. The images below show a flooded residential neighborhood in Norfolk (left) and the flood mapping I did (right) using the Sea Level Rise phone app. Walking the edge of the flooded zone, I dropped GIS pins every 4-5 feet and got an outline of the flooding., showing the extent of the inundation. The data set can be exported as an .xls or .csv file and transformed into a shape form on a map and used to test inundation models. All of this helps us project where the water will come next time we get +4' of water.

Climate Change = Intense Rain = More Pollution

Yesterday (July 18, 2017) we had one of those intense rain events we're seeing with increased frequency. My rooftop rain gauge measured 1.8" of rain in two hours. I was out picking up my daughter at track practice when it hit and got stranded - see windshield shot as I was stopped in a flooded intersection. Last week we had another ~2" rain event.

This morning walking my dog, there was sediment in the streets everywhere. It washed into the Elizabeth and Lafayette Rivers here in Norfolk and was like dumping bags of fertilizer into the rivers. My wife, Dr. Margaret Mulholland, is a biological oceanographer studying algal blooms and she said they are already seeing harmful algal blooms due to last week's deluge...yesterday's "rain bomb" will only add to it.

So going forward we need to add climate change/rain intensity to our stormwater management plans. We get ~60" of rain a year here in Norfolk. If we get 120, 1/2" rain events, no problem, the existing stormwater management systems can handle it. We get 30, 2" rain events, the pollution wins.

This increasing intensity was studied by Peter Popmmerenk who is a planner with the City of Virginia Beach's Stormwater Department. He went to the weather record at Norfolk International Airport and...sure enough, he found an increase in 2" rain events since 1950....measured, not projected from someone's model. The relevant diagram is below - click on the image for his full paper.

 

Just another part of the challenge with flooding/stormwater.