Mt Airy, Philadelphia

TED Talk by Yann Arthus-Bertrand

Kelly — Tue, 21 May 2013 00:15:42 +0000

Stormwater Pollution Research – Washington State

Kelly — Sun, 19 May 2013 19:01:37 +0000

This video shows research into stormwater pollution in the Seatle Washington, Puget Sound area.

Tookany – Tacony Creek Stormwater Trash Pollution Update

Kelly — Wed, 15 May 2013 21:02:58 +0000

The may 15, 2013 update on the Tookany – Tacony Creek stormwater trash pollution problem is available as a pdf file Update_5_16_13.

Philadelphia and Cheltenham Litter is Polluting Upper Rock Creek

Kelly — Thu, 09 May 2013 18:04:12 +0000

Philadelphia and Cheltenham litter is flowing through storm sewers and overland to Rock Creek where it builds up in trash piles on tree branches or along the Creek banks.

Rock_Creek_Litter_Pollution_small

Philadelphia Creek Trash Assessment Methodology

Kelly — Thu, 09 May 2013 17:53:05 +0000

There are a number of techniques for analyzing various aspects of urban creek trash problems, however, the author has not found a systematic, reproducible methodology for comprehensively investigating the sources and severity of creek trash problems.

This paper applies a 3 step Philadelphia Creek Trash Assessment process to the Mill Run Creek trash situation to demonstrate an analysis approach that could be applied to Philadelphia area creeks to establish the extent and potential sources of creek trash.

The Mill Run Creek offers an excellent location to develop and test creek trash assessment techniques because it only has one type of source, stormwater outfalls. Since PWD’s T-088-01 outfall makes up the entire “upstream flow” for the Creek, we do not need to worry about other upstream sources. Inspection of the area around the Creek shows that there is minimal potential overland flow of litter/ trash and illegal dumping.

Here is the pdf link. MRC_Assess_contributions

Potential Role of PWD Outfalls in Tookany – Tacony Creek Trash Problem

Kelly — Thu, 09 May 2013 17:39:38 +0000

Have you ever wondered why the Wissahickon Creek is so clan and the Tacony Creek is so dirty?

After conducting numerous field surveys, I’m beginning to understand the Tookany – Tacony Creek trash situation. I’ve found 10 Philadelphia Water Department stormwater outfalls with evidence of trash in the outfall channel or immediately downstream of the outfall, making hte outfall a suspect for trash discharge to the Tookany – Tacony Creek.

This pdf documents my concerns about the discharge of floatable trash from PWD outfalls: Potential_role_of_10_outfalls

10 PWD Outfalls That Discharge Trash to Tookany – Tacony Creek

Kelly — Wed, 08 May 2013 23:09:58 +0000

There are approximately 300 outfalls that discharge stormwater to the Tookany – Tacony – Frankford Creeks. Litter from streets, parking lots and illegal dumps is carried to the Creeks by run-off during/ after rain storms.

This slide shows takes you on a tour of 10 Philadelphia Water Department stormwater outfalls that carry Philadelphia litter to the Creeks.

Map of Creek and 10 PWD outfalls with trash

A pdf file of this slideshow is available here.

Tookany – Tacony Creek Stormwater Trash Pollution Update

Kelly — Sun, 14 Apr 2013 14:29:22 +0000

The Tookany – Tacony Creek has a serious stormwater trash pollution problem. This update highlights several findings on the sources and extent of the problem.

Where – shows several Tookany – Tacony Creek stormwater trash pollution sites
Sources – shows role of both separate and combined sewer outfalls as well as overland flow discharges on Tookany – Tacony Creek trash pollution
Rating Creek Trash Conditions – applies Rapid Trash Assessment (RTA) score to Mill Run Creek to show how this technique works
Channel Roughness – shows how channel conditions affect creek trash buildup rate
Types of creek trash – shows how floatable trash (plastic bottles) and neutral buoyancy trash (plastic bags, wrappers) behave differently in the Creek
Shows how neutral buoyancy material may be passing through PWD’s trapped inlets

The most recent Tookany – Tacony Creek stormwater trash pollution update is available as a YouTube video below. (To Enlarge video to full screen – click right icon, menu bar at bottom of YouTube window)

A PDF file copy of the slides is available here: Tookany_Tacony_Trash_Update

James Hansen in his own words

Kelly — Sat, 13 Apr 2013 00:55:53 +0000

What happens to Tookany Creek when it rains?

Kelly — Wed, 03 Apr 2013 23:33:14 +0000

Tookany Creek, Tacony Creek in Philadelphia, has both flooding and creek trash problems that affect Cheltenham and Philadelphia residents. I have written about the Tookany -Tacony Creek trash problems here, here, here and here.

Today, I am starting a series on the Tookany Creek flooding situation to address 2 keys questions:

Is global warming changing precipitation patterns in the Philadelphia area
What are Tookany Creek flood flow trends

This post discusses Philadelphia area precipitation trends to address the question on how perceived increases in rainfall intensity may be affecting flooding in Cheltenham Township. A later post will review the Creek flow data.

Rainfall Data at Philadelphia International Airport (KPHL)

Daily rainfall data dating back to 1874 is available at the Phillyweather.net site where users can download an Excel workbook with daily data (link). I used the Phillyweather.net data to evaluate changes in precipitation patterns. Here is what I found:

Frequency of high intensity rain storms has increased since 1960. There were only two 4-inch or more rain storm events in the 86 year period 1874-1959, compared to 12 storm events in the 52 year period 1960-2012.
The calculated 100 year return period daily precipitation in the 1874-1959 period was 5.11 inches, that value increased to 6.86 inches in the 1960-2012 period.
9 of top 10 rain storms in the 1874-2012 period occurred since 1960

Details

Most people have heard about the “100 year storm“. It is actually the storm that has a 1% chance of occurring in a given year. The figure bellow shows how we can use precipitation frequency analysis to estimate the the 100 year storm for Philadelphia International Airport. Tthe plot shows the peak rain storm in inches per day for each year from 187 4 to 2012 plotted on a Gumbel probability grid (link). This allows us to identify the rainfall for any return period, say 10 years or 100 years.

The estimated storm 100-year return period, isng the entire 1874-2012 data period is 5.83 inches. Since we know that rain intensity has been changing, I’ve also calculated the 100 year storm estimates for the pre-1960 and post 1960 periods, as shown in this 2nd chart.

The calculated 100 year storm is affected by the period included in the precipitation frequency analysis. If we just consider the 1874 to 1959 period, we get a 100 year return period storm of 5.11 inches. If we include just the 1960 to 2021, we get 6.86 inches. Clearly we are seeing higher intensity storms since the 1960s.

NOAA, using more sophisticated techniques, estimates the Philadelphia Airport 100 year – 24 hour storm to be 7.72 inches (link). Since the maximum 1874-2012 24 hour rain was 6.83 inches, Philadelphia Airport has not seen the NOAA 100 year storm yet.

Perspective on Variation in Rainfall Across our Region

This NOAA map shows the 100 year return period rain for the mid-Atlantic region, including Pennsylvania, Delaware and New jersey. Notice the green – yellow areas in western Pa and the purple areas in Delaware and New jersey. The green – yellow ares have estimated 100 year storms of 5 – 6 inches while the purple areas have storms of 10 – 11 inches. The Philadelphia area is right in the middle at 7.01 – 8 inches.

(Click image to enlarge)

You can access this NOAA map here.

The next post will discuss Creek flow data from the USGS gaging station at Adams Avenue.

Do you have data related questions about rainfall and creek flow? If you do, let me know and I’ll see what I can do. Just click in the the Reply box and submit your question/ comment.