At the start of the month, we talked about the Paris climate change conference and what we're doing to prepare for global warming. Record high temperatures were set over the weekend and more highs are likely this week. But it’s another warm weather-related event that has us concerned: Last Sunday, December 6, was the first time in fall 2015 that the official temperature at Philadelphia International Airport was at or below 32º F.

This is about a month later than the average date of the first freeze, and it's the first time we've gone without a freeze through November. In fact, when looking at the period of record from 1948-2015, it's the latest the first freeze of the year has happened, beating the previous record of November 28, set in 2010, by eight days. And while weather is not climate, the date of the first freeze has been getting later over the last few decades. 

We can't say it enough: Green City, Clean Waters represents a major shift in the way we think about and do infrastructure. That means the tools we use to effectively manage stormwater—collectively called Green Stormwater Infrastructure or GSI—look and work differently than the traditional pipes and sewers people are used to seeing.

One big difference is that these green tools have a much more noticeable presence in neighborhoods because they use things like trees, grasses, soil and stones on the surface to slow down water from storms that can overwhelm our sewers. In addition to managing stormwater, these green tools are also designed to have the same community benefits we get from having beautiful parks and gardens in our neighborhoods; in many cases, a stormwater tree trench or a rain garden can look pretty much just like your everyday street tree or landscaped garden.
That tendency to blend in can be misleading though, because GSI can be sort of like an iceberg: we see the green tip of it on the sidewalk, in a park or on the street, but the bulk of the infrastructure is spread out over a large area underground.
This diagram of typical street tree trench is a good example:

A diagram of a typical street tree designed by Philadelphia Water.

Because GSI is a relatively new concept, even plumbers and construction contractors aren't always aware of its presence or don't realize how much is going on below the surface. That can lead to costly mistakes that could damage Green City, Clean Waters infrastructure and hurt a neighborhood's ability to manage stormwater.

To avoid accidentally damaging these important tools, we put together a simple FAQ for plumbers and contractors to help them understand how GSI works, what it looks like, and what they should do if they're working with or near Philadelphia Water's green infrastructure. Click on the image below to get a full-size copy of the GSI FAQ for plumbers and contractors, which includes important phone numbers and contact information. If you're a resident and think you see construction that's damaging green infrastructure in your neighborhood, this FAQ sheet could be useful for you too:

If you are involved with a community group that hosts zoning meetings or have other interactions with developers in your community, please feel free to share this helpful FAQ with them, especially if you know a project could impact nearby green infrastructure. With Green City, Clean Waters set to increase its footprint dramatically over the next two decades, it's more important than ever for the development community to understand how green tools work so we can all meet the goal of improving our water quality!

Northern Liberties flooding that occurred after a July 9 downpour. Credit: Northern Liberties Neighbors Association.

After yet another heavy rainstorm last week, a section of Northern Liberties experienced localized flooding as result of an overwhelmed stormwater system.

This area contains the historic Cohocksink Creek and is the focus of a long-term infrastructure improvement project. Traditional sewer expansion and green stormwater tools will improve the capacity of the local system while reducing the amount of water entering sewers.

Philadelphia Water is aware of last week's flooding and on-going issues, and we're working with the community to address immediate concerns as we implement a plan to improve conditions in the long haul.
You can see a summary of plans to address flooding in the vicinity of Wildey and N. American streets here and here.

Impacted residents are also encouraged to attend a community meeting on the Northern Liberties Storm Flood Relief Program. Philadelphia Water representatives will discuss flood reduction efforts at the South Kensington Neighborhood Association,1301 N. 2nd St., on Tuesday, July 14 at 6:30 p.m.

Stress on the Sewers: Is June Philly's New Monsoon?

The July 9 storm dumped nearly an inch of rain in just under 10 minutes—the heaviest of the month so far—and came at a time when the Delaware River was at its highest tide level.

It’s been a rather wet summer so far, and that means additional stress for stormwater infrastructure. After a historically dry May, June made up for it with a vengeance. Only two years have seen a wetter June in the city, according to records dating to 1872.

The wettest June ever was in 2013, followed by 1938 and 2015 with 8.88 inches. The National Weather Service lists June’s rain average as 3.43 inches.

It’s all part of a trend that has seen six of the rainiest Junes EVER occur in the city in just the last dozen years:

June 2013: 10.36 (1st)

June 2015: 8.88 (3rd)

June 2003: 8.08 (4th)

June 2006: 7.95 (6th)

A green roof on the Granary Building that was built in part to meet Philadelphia Water's Stormwater Regulations. Changes to the regulations are designed to encourage even more private green infrastructure projects. Credit: Philadelphia Water

Every time something new gets built in Philadelphia, it presents an opportunity to improve the way we deal with stormwater runoff—a big source of pollution that hurts our waterways, but often gets overlooked as “just rain.”

In order to make sure new development contributes to Philadelphia’s vision for a modern stormwater system that protects our rivers and creeks, we have a set of standards—collectively called Stormwater Regulations—that let developers know how their property should handle the water that comes from rainstorms and other wet weather events.

It’s been nearly a decade since we established our Stormwater Regulations in 2006, and starting July 1, 2015, new construction projects will have updated rules for managing stormwater. These changes reflect evolving agreements between Philadelphia and the Pa. Dept. of Environmental Protection, (the state agency that regulates our local waterways), and the EPA.

In order to make sure the development community and the public are fully aware of our updated Stormwater Regulations, we’re holding a series of public information sessions. If you’re interested in learning more—especially if you’ll be working on a new construction project—you should click here and register to hear more details about the changes.

The information sessions are scheduled for June 23rd and 30th and July 9th and 23rd from 8:30 a.m. to 11:30 a.m., and will be held in the Municipal Services Building, 1401 JFK Blvd.

Stormwater management on development sites is critical to the success of Green City, Clean Waters. Since 2011, private developers have built over 900 green stormwater management tools in the city, and the new regulations will provide incentives for even more.

Quick Read: What the Changes Mean

Water Quality Improvements

Manage more water. The Water Quality Volume will increase from 1 inch to 1.5 inches. This will help reduce combined sewer overflows and local flooding, with minimal impact to site design. Applies to all development sites.

Slow water entering sewers. The peak release rate will decrease from 0.24 to 0.05 cubic feet per second per acre of non-infiltrating impervious area. This will make the rate at which water leaves a site and enters the sewer system equal to the rate at which treatment plants can clean the water. Applies to about 23 percent of projects each year.

Clean water entering sewers. Philadelphia Water will require 100 percent of surface runoff that can’t infiltrate the ground to go through a pollutant reducing practice. This requirement will remove pollution from the dirtiest stormwater on a property. Applies to about 23 percent of projects each year.

Business-Friendly Improvements:

Faster project approvals. Philadelphia Water is introducing “Surface Green Review,” a new expedited review process for sites that use surface practices to manage stormwater.

Simpler application resources. Simplified technical worksheets and Plan Review application resources will improve the quality of submissions and reduce review times. By using these resources, designers will know before submitting that their projects meet regulations.

Accessible information. The new digital Stormwater Management Guidance Manual and Plan Review website will provide better information in a user-friendly format.