Tropical Storm Fay (link1, link2) passed through Philadelphia on July 10, 2020. This storm dumped 2 – 4 inches of rain on the Philadelphia area from about 8:00 AM to 4:00 PM on Friday, July 10th.
This plot shows NOAA’s Advanced Hydrologic Prediction Centers (AHPC) precipitation map for Philadelphia as of 8:AM on July 11, 2020.
The map shows the historic Wingohocking Creek Watershed which covers a major portion of NW Philadelphia. You can see that the Wingohocking Watershed received anywhere from 2.5 to 4 inches of rain over this storm.
This storm caused significant flooding at Belfield and Church. A local resident captured the video of the flooded intersection and posted it on Facebook at this link.
COVID-19 cases are increasing at exponential rates across many countries. Our World Data (link) is providing daily updates on the number of confirmed COVID-19 by country. Here is the March 20, 2020 chart.
This interactive chart lets you highlight the trajectory for a specific country and compare it to the number of confirmed cases for other countries by day after the 100th confirmed case. Viewers can also download a CSV file of the data by pressing the DATA tab. this can be helpful to to prepare COVID-19 trajectory charts for just a few countries to help seeing the trends for specific countries.
This chart shows Italy’s trajectory because it is the country with the highest number of confirmed cases. S Korea is also included to show a country that has been able to stabilize their number of confirmed cases.
The 3/21/20 data shows that the US trajectory has now passed where Italy was on the 18th day, indicating that we are currently on a path comparable to Italy’s.
The Philadelphia Water Department has released an executive summary (link) of their multi-year study of stormwater flooding in Germantown – E Mt Airy. Their findings provide a wake-up call on flash flooding risks in this highly developed part of Northwest Philadelphia.
The combined sewers that the City built in the late 1800s and early 1900s to enclose the Historic Wingohocking Creek are simply too small for today’s stormwater runoff, causing sewer backups in nearly 2,800 homes and local flooding in the 24 intersections highlighted in this map.
PWD estimates flood annual flood damages of $7.1 millions to buildings and $1.6 million to vehicles.
PWD conducted detailed investigations into 2 storm relief options: 1) stormwater storage, and 2) tunnel relief. Both options are shown in the Executive Summary, however they are difficult to read. The map below reproduces the Water Department’s Storage Option.
Do you live in a flash flood prone area in Germantown – E Mt airy? If you do, your 1st priority should be to obtain flood insurance. Your 2nd step should be to ask your local elected officials, PWD, and your local community groups what steps they are taking to inform the public about our flash flooding problems and steps to reduce the risk.
I will be giving on January 29th, 7:00 PM at Lovett Library. Flash flooding has been a problem in E Mt Airy and Germantown with Haines and Belfield as the epicenter.
My talk is the 2nd in a 4 part series about Historic Mt Airy (link). I’d like to invite you and your associates to this talk on the history of the Wingohocking, why it was converted to a combined sewer, the resulting reshaping of the watershed’s landscape which allowed extensive development which then lead to our current flash flooding problems.
I am hoping to develop support for a Wingohocking Watershed Zoning Overlay that would require impervious land cover restrictions comparable to those now required in the Wissahickon Watershed Overlay.