This document discusses urban stormwater issues in Providence, Rhode Island and the benefits of green infrastructure solutions. Providence faces challenges from aging infrastructure, high percentages of impervious surfaces, and industrial contamination near waterways. Green infrastructure approaches like rain gardens, swales, green roofs, and depaving lots can help address stormwater while providing community benefits like recreation, health, habitat, and economic development. Providence is pursuing green infrastructure projects in parks and vacant lots to manage stormwater and provide multiple benefits. Challenges remain around long-term maintenance of green infrastructure sites and further incentivizing private property owners.

1. Urban Stormwater Conditions and
the Multiple Benefits of Green
Infrastructure in Providence
2016 RIFMA Conference: Incentivizing Actionable Resilience to Flooding,
April 7, 2016
David Everett, Principal Planner/Environmental Coordinator

2. Urban Landscapes and Green Infrastructure:
Setting the Scene
• Non-traditional “flooding”/distinctly urban stormwater issues
• Climate Disorder
• Resource/Capacity Deficiencies
• Green Approaches to Stormwater Management
• Multiple Benefits
• Challenges and Food for Thought

3. Old industrial Providence

4. Urban context presents specific challenges: Providence is
an old, largely impervious city with aging infrastructure
and considerable “deferred maintenance”

5. Current estimates calculate 59% impervious surface.* The Jewelry District,
pictured below, is an area of the city that has a particularly high percentage
of impervious surface and is situated adjacent to the Providence River near
the head of Narragansett Bay.
*Providence Division of
Forestry, i-Tree Eco
System Analysis 2014

6. Jewelry District Parking Lots

7. The Woonasquatucket River runs through intensely industrialized
neighborhoods. Much of the river is channelized, infrastructure is in
disrepair, and impermeable surface is widespread. Climate change and the
increasing intensity of storms only exacerbate the situation…
Photographs by Bruce G. Hooke, courtesy of the
Woonasquatucket River Watershed Council

8. As a post-industrial city that is also a port city, Providence must
contend with contaminated soils and hazardous materials close to the
water’s edge. These conditions pose storm impacts on water quality
and limit infiltration and diversion options to mitigate flooding.
Allens Avenue from
the Providence River,
David Everett

9. Considerable gains have been made from a water quality perspective,
but it’s clearly not enough – and a brief downpour that used to have
minimal consequences may now cause considerable localized flooding
– flooding that, in turn, has water quality impacts…
• The Narragansett Bay Commission Combined Sewer Overflow abatement
project has greatly improved the quality of water in our rivers and the bay
• …but continued water quality regulation non-compliance and increasing
flooding led to ongoing efforts to institute an Upper Narragansett Bay
stormwater utility district
• …municipalities are under-funded and ill-equipped to address these issues
under the current scenario: relatively simple operations and maintenance
tasks such as catch-basin cleaning and street-sweeping are deferred,
causing streets to back up with water even during minor storms (and
contribute to runoff pollution)

12. In the past, we’ve thought of cities as paved places, as unnatural
environments, but the confluence of factors suggests we need to think
about new ways of doing things. Providence and other cities have begun
to do just that:
• Higher per lot permeability standards
• On-street parking (what a concept!)
• Improved transit and expanded transit options
• Improved bicycle and pedestrian infrastructure
• Creative Depaving and Green Infrastructure pilot projects

13. Green Infrastructure and the “multi-benefit” approach:
While removing hard surfaces and installing rain gardens, vegetated swales, green
roofs and other green infrastructure in cities, it’s important to do so with multiple
benefits in mind:
•Open space/green space
•Recreation
•Health
•Connection to nature
•Urban agriculture/community gardens/farmers markets
•Traffic calming
•Art space
•Gathering space/community-building/inclusion
•Habitat
•Economic development

14. Bucklin/Dexter existing conditions (before GI intervention)

15. Bucklin/Dexter “After” conceptual rendering (not the final plan – trees are desired both to aid
in infiltration and evapotranspiration and to provide heat island mitigation but they are
expensive and must have sufficient minimum canopy height to ensure sightlines – the final plan
is likely to have a few trees and more low-lying plants)

16. A number of post-industrial cities have started programs based primarily on
“greening vacant lots” – often with stormwater management in mind -
while achieving multiple benefits in the process. These include:
• Baltimore’s Growing Green Design Competition: variety of uses sought for
vacant lots; proposals included a combination garden/bio-swale, green
parking, displayed art, flower growing, recreation and open space
• Buffalo Sewer Authority’s Greening Vacant Lots: driven by CSO control
compliance/consent decree, 30% green infrastructure to complement the
“gray,” removal of hundreds of structures and pavement, disconnection of
pipes, retention of trees, removal of invasives, employment of formerly
incarcerated workforce….”green” demos with multiple benefits to the
community
• Cleveland Botanical Garden/Green Corps: started with urban agriculture;
scattered vacant sites, green infrastructure, lots with slope and stormwater
capture prioritized; low-maintenance lawns surrounding bio-retention areas;
coordinated with downspout disconnects; informal uses/play sites

17. Providence has 500-600 vacant properties and many over-paved lots
• In addition to reestablishing housing, GI sites can help with localized and
overall stormwater management while providing many of the benefits cited
• Many lots were over-paved, ostensibly to provide parking on-site, as well as to
minimize maintenance. With on-street parking now available by permit, change
has not come quickly – without incentives, why change? (esp. if you are an
absentee landlord)

18. A combination of factors (provision of on-site parking in the absence of on-street
parking, zoning variances, scofflaws, and minimal lot maintenance) have led to grossly
over-paved conditions and, to date, incentives are not in place to depave.

19. Parks provide green infrastructure opportunities too
• GI projects have been completed in Roger Williams Park, minimizing impermeable
surface and runoff to ponds
• Proposed citizen-led plans to remake “River Road” along the Seekonk initially
responded to erosion and stormwater concerns, along with quality of life issues,
and have inherently taken a multi-benefit approach: bike/ped, fishing, kayaking,
amenities, ecological restoration, and stormwater management

21. Thanks to organizations including the Green Infrastructure Coalition, the
Woonasquatucket River Watershed Council, Groundwork Providence,
Brown University’s TRI-Lab, City departments, and collaborative efforts
including all of these entities, small GI projects are now being
implemented in various parts of the city.

22. Challenges and Food for thought:
• In addition to obvious and measurable impacts on water quality, absorption
and flood control, and along with the multiple benefits that green
infrastructure can provide – and as this becomes a common way of thinking –
we should also be thinking about the maintenance and aesthetics of green
infrastructure.
– Adopt-a-GI site?
– New site planning and park design typologies?
– Incentivizing depaving
– Stormwater retention credits

23. finis
deverett@providenceri.com
David Everett