This year, it has rained 55 inches in Providence so far, and with the projected rainfall in the remainder of December, the accumulated rainfall will equal 2023’s 58 inches. Normal annual rainfall in Providence used to be 44 inches. As more and more storms deliver more and more rain, that water has to go somewhere. In 2024, Providence spent more money on flood issues than on snow removal. Stormwater management in the city is receiving increased attention and requires even more.
Providence Stormwater Flows
Stormwater flows into pipes below the street which then carry it to bigger pipes (called interceptors) and then into one of several Providence waterways.
When it rains, stormwater flows from properties and from streets into either 1.) combined stormwater and sanitary sewer pipes; or 2.) into separate stormwater pipes.
Combined Pipes
Many decades ago, city engineers thought it most efficient to combine stormwater and sewer wastewater (ironically called “sanitary”) into the same pipes under the city streets. All of Providence’s sewage pipes were supposed to end up at the Fields Point treatment plant, be treated, and empty into Narragansett Bay. It seemed like a good idea at the time, but it has turned into a water pollution disaster.
If the rain is heavy, the combined flows often exceed the capacity of the combined sewer and stormwater interceptors and never make it to the Fields Point treatment plant. Instead, combined sewage and stormwater flows into combined sewer outfalls (CSO’s) directly into Providence rivers. So, untreated sewage goes into the Providence River and then into Upper Narragansett Bay.
The Narragansett Bay Commission (NBC) has spent about $1 billon (that’s not a typo) in the last 12 years to construct combined sewer and stormwater tunnels underground to divert combined sewer overflows (CSO) into tunnels to eliminate CSO overflows into the Woonasquatucket and the Providence Rivers. These tunnels have dramatically improved the water quality of both the rivers and even has allowed limited shell fishing to resume in Upper Narragansett Bay. (Editor’s note: see The PVD Eye’s previous story about the Moshassuck River)
The NBC is now undertaking a third and final tunnel in the Pawtucket and Central Falls area to eliminate the CSO overflows into the Blackstone River which flows into the Seekonk River before reaching the Providence River.
Unfortunately, not all the CSOs in Providence have been eliminated. Many smaller CSOs that are the responsibility of the City of Providence, were not able to be diverted into NBC tunnels. These are scattered all over the city and during heavy rainfalls they pollute such waterways as the West River and the Woonasquatucket River before flowing into the Providence River.
Impacts of Providence Stormwater: Water Quality Impairment
Providence has miles of street where stormwater flows directly into stormwater-only pipes that discharge into Providence waterways. Unfortunately, stormwater flowing across residential and commercial property can produce several types of pollution that impair Providence water bodies.
Nutrients: Excessive nutrients can cause aquatic weed growth and algae leading to cyanobacteria blooms affecting recreational water use. The ponds in Roger Williams Park and Mashapaug Pond suffer from these sources: animal waste (dog and bird droppings), lawn fertilizers, and pollutants from large upstream parking lots. At a recent stormwater conference at Roger Williams Park, Deputy Superintendent of Providence Parks Brian Byrnes noted that “the future enjoyment of the ponds at Roger Williams Park depends on reducing polluted stormwater that flows into Mashapaug Pond and then into Roger Williams Park”.
Bacteria: Excessive bacteria from bird droppings on roofs and dog waste in yards can lead to fish kills impacting recreation.
Oil and Grease: Driveway runoff is toxic to all aquatic life.
Impacts of Providence Stormwater: Street and Property Flooding
Two trends have led to more street and property flooding in Providence: 1) more building development with more impervious surfaces and 2) more high intensity rain events that create flash flooding in a short period of time. Climate scientists are warning that extreme weather events like the rain events that Providence received in the last two years may be a part of our future weather patterns.
Examples of Providence property and street flooding in 2024. Photos courtesy of the City of Providence.
To reduce flooding in the city, major efforts have to begin to reduce existing impervious surfaces in the city and to ensure that future development limits the amount of stormwater that flows off site.
The City of Providence Is Under a DEM Consent Decree to reduce Stormwater Pollution
While the Narragansett Bay Commission has successfully leveraged sewer use fees to build CSO tunnels to eliminate most CSO outfalls and improve the water quality in several Providence rivers, DEM is requiring the City of Providence to take action to reduce stormwater pollution in the city and to reduce the impact of remaining CSO’s. This DEM decree is intended to get Providence into compliance with the federal Clean Water Act.
Providence is responsible for over 300 miles of stormwater, sanitary, and combined sewer pipes and hundreds of catch basins and outfalls, yet has no user fees to maintain this infrastructure. (Editor’s note: see today’s Providence Counts for more data)
Funds presently used from the city’s General Fund to maintain all its sewer and stormwater infrastructure are totally inadequate. The need for funds for the Police Department and Public Schools, for example, generally trump dollars needed to clean and repair stormwater and sewer lines.
While the DEM consent decree was issued in 2017, the Elorza administration largely did not address DEM’s water quality concerns. With the election of Mayor Smiley, the City is beginning to responsibly develop an effective and equitable user fee to pay for all the stormwater and sewer issues that are impairing the City’s waterways.
User Fees
In a recent presentation on the City’s stormwater management plans, Chief of Policy and Resiliency, Sheila Dormody, indicated that the City hopes to have an equitable stormwater and sewer user fee proposal for consideration sometime in the spring of 2025.
How might a sewer and stormwater user fee be applied to property owners? Much like the water fee paid to Providence Water and the sewage treatment fee paid to the Narragansett Bay Commission, a Providence sewer fee would probably also be based on a property owner’s actual sewage flows from the property.
A separate fee for stormwater would be billed to all property owners, and that fee would likely be based on the amount of impervious surfaces on a particular property that is generating stormwater flowing off the property into the street.
For example, in a typical triple-decker, the stormwater fee would be based on:
roof-800 squarefeet
driveway-420 square feet,
walkway (sidewalk up to front steps)-40quare feet
total =1,260 square feet
Hypothetically, say the stormwater fee is $.05/sq. ft./year. That equates to $63/year or $5.25/month.
Applying this type of methodology across all residential, commercial, and industrial property owners in the city 1) would generate adequate funds for the city to have a first-rate stormwater and sewer system to be eventually in compliance with the Clean Water Act, 2) free up General Fund funding for the city public schools, 3) provide cleaner and more useable waterways in Providence for Providence residents, and 4) reduce street and property flooding in flood prone areas of the city.
What Can Residents Do To Mitigate Stormwater Effects?
Residents can reduce the amount of impervious surface area generating stormwater flowing onto the street or flowing directly into a stormwater and combined sewer line. According to Providence’s Chief of Policy and Resiliency Sheila Dormody, property owners will be able to reduce or even eliminate a stormwater user fee by taking actions to manage their stormwater on site. There are some relatively easy-to-implement ways to reduce stormwater runoff.
Almost 20% of Providence residential downspouts are connected to a standpipe that is tied directly into the street stormwater line and those downspouts can be diverted onto the land.
Options for rainwater diversion
Downspout diversion into planter boxWhat Can the City of Providence Do to Improve Stormwater Management
Residential Property Owners
- More consistent and long-term outreach and public relations is needed to encourage and support on-site options for residential stormwater management. A more broad- based and sustained effort is needed to build awareness of the value and relative ease of adopting residential stormwater management.
- A mechanism for providing technical assistance to property owners to install best management stormwater practices is needed. Web site info is good enough for many homeowners, but some way to handle practical homeowner questions for particular properties would ensure that installations are completed properly. A link on the City web site to video installation examples would meet perhaps much of this technical assistance need.
- Another way of providing technical assistance to property owners is to develop a “Volunteer Stormwater Squad” that would be managed by a non-profit during summer months using high school and college students. These volunteers would provide hands-on, in-person, no-cost technical assistance to property owners.
- Buy rain barrels in bulk and help residential property owners install them.
Commercial, Industrial and Major Residential Developments
- Continue to require all new major development (projects greater than 1 acre in size) to manage stormwater on site.
- Develop regulations and procedures to require existing major developments to retrofit their property with stormwater best management practices.
- Where possible, city streets should be retro-fitted with tree filters and rain gardens, perhaps in new bump out areas to absorb stormwater so that it doesn’t flow into the storm drains.
- All new city paving projects should include options to retrofit streets with tree filters and rain gardens.
Bob McMahon has been a Providence resident since 1978. While an officer in the US Navy, he participated in the recovery of the Apollo 11 astronauts in the Pacific Ocean in 1969. He has a city planning background and worked in the Providence Parks Department for 30 years, first as Deputy Superintendent under Nancy Derrig and later as Superintendent. Married to Pam Kennedy, they have two adult sons, James and Robert. He is a volunteer for the San Miguel School and St. Pius V Church in Providence. Daily devotee of the New York Times word games: Wordle (3.0 average guesses) and Spelling Bee (859 straight days Genius level).
