Storm Water Program > Guidance > Design Manual:
Coordinated Stormwater Permitting Info
Stormwater Manual Training
Rules and Guidance
Final Stormwater Manual
RI Stormwater Management Guidance for Individual Single-Family Residential Lot Development
LID Site Planning and Design Guidance for Communities
Redevelopment Criteria Guidance
Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices
Addressing Barriers to LID (EPA)
Manual Changes- August to December
Draft Stormwater Manual & Appendices
Final Freshwater Wetlands Regulations
Wetlands Regulation Changes- August to December
Draft Freshwater Wetlands Regulations
Final Water Quality Regulations
Water Quality Regulation Changes- August to December
Manual Track Changes – April to August
Response to Comments - May 2010
Snow Disposal Policy
1993 Storm Water Design and Installation Standards Manual
Reports and Publications
Summary of Revisions
Background Document for Draft Manual
RI Stormwater Design and
Installation Standards Manual
The Department of Environmental Management has filed new stormwater regulations that will dramatically impact the design of new development and redevelopment projects. The new regulations consists of a completely updated and expanded stormwater design and installation manual and changes to the state's Freshwater Wetlands and Water Quality Regulations that explain when the changes apply to future applications submitted to the agency. Also included in the new regulations are provisions for a time extension for previously issued development permits, as required by the so-called "tolling statute" enacted by the General Assembly in the last session.
The revised Rhode Island Stormwater Design and Installation Standards Manual was under development for several years and has undergone extensive public review and comment. The major impetus for the revised manual was the "Smart Development for a Cleaner Bay Act" passed in 2007. The law states that "stormwater, when not properly controlled and treated, causes pollution of the waters of the state..." and "development often results in increased storm water runoff by increasing the size and number of paved and other impervious surfaces..." The law required DEM and the Coastal Resources Management Council to amend the 1993 stormwater manual to require recharge or infiltration of a portion of stormwater into the ground and use of low impact development (LID) techniques as the primary method of stormwater control. DEM and CRMC jointly developed the revisions and CRMC is scheduled to also adopt the revised manual in the near future.
"Implementing the new stormwater requirements will be challenging for all parties involved and will involve a learning process, as users begin incorporating the changes into their practices," noted DEM Director W. Michael Sullivan, PhD. "The floods in the spring of 2010 must not be forgotten and these new standards will help to reduce future problems. The Department is establishing a point of contact within the agency to provide assistance as well as a standing committee of government and private sector stakeholders to help guide the process and identify permitting issues or further policy needs as the program develops."
DEM has documented widespread water quality problems caused by stormwater runoff, including stream impairments, beach closures and shellfishing closures. The new manual includes water quality performance standards that stormwater management practices must meet in order to minimize impacts to our waters, including both surface water and groundwater. The typical stormwater detention pond, which has been widely used during the past 20 years, is no longer considered adequate for water quality treatment. More effective water quality treatment practices are now available, many of which are already familiar to the engineering and design community, including infiltration basins, bio-retention filters, grass swales, and wet vegetated/soil treatment systems.
Of greater overall long term benefit, however, the manual incorporates LID as the "industry standard" for development, representing a fundamental shift in how subdivisions and commercial projects are planned and designed. LID is a more comprehensive approach to managing stormwater that minimizes the hydrological impacts of development. Stormwater is managed in smaller, more effective treatment practices located throughout the development project rather than being conveyed and managed in large pond facilities located at the bottom of drainage areas. The primary goal of LID is to mimic the predevelopment hydrology by using site planning and design techniques that store, infiltrate, evaporate, and detain runoff as close as possible to the point where precipitation reaches the ground. Use of these techniques helps to reduce net runoff and ensure adequate groundwater recharge. DEM is developing a separate guidance manual, due out next month, exclusively on the LID design approaches that will aid local communities in adopting LID standards and help developers plan projects that will be significantly more protective of the receiving water bodies and nearby wetlands.
As announced in DEM's August notice of rule change, the revised manual becomes effective on January 1, 2011 and will be applied to permit applications received on or after that date. An extension to the deadline for compliance with the new manual – to June 30, 2011 – is provided for certain projects that are already in the planning or design process, including projects currently before local planning boards and several DOT road and bridge projects.
The tolling or permit extension provisions apply to development projects with permits valid as of November 9, 2009 or later. Permits will not expire until June 30, 2011 or later. Most permits will be extended longer, with some as long as 598 days from when they would have otherwise expired. The purpose of the extension is to aid projects impacted by the recession, enabling quicker start-up once economic conditions sufficiently recover or financing becomes available.
The DEM point of contact for questions about the manual is Eric Beck who may be reached at 401-222-4700 Ext. 7202. Also, questions may be addressed by e-mail to email@example.com. To schedule a meeting to discuss application of the manual on a specific project, please contact the Office of Customer and Technical Assistance at 222-6800.
TrainingDEM and CRMC, in conjunction with the University of Rhode Island, have scheduled a series of public training sessions beginning on January 13 to help acquaint users with the new manual. Further information about the training sessions is available at www.ristormwatersolutions.org/SW_wevents.html.
1993 Stormwater ManualThe 1993 State of Rhode Island Storm Water Design and Installation Standards Manual, developed by RIDEM and RICRMC, was in effect until the new manual was officially adopted.
In promulgating the 2010 Rhode Island Stormwater Design and Installation Standards Manual ("RISDISM"), which went into effect on January 1, 2011, RIDEM recognized that not all of the requirements for each of the Minimum Stormwater Management Standards contained in the RISDISM would be appropriate for single-family development projects. In some cases, the certain elements of a Minimum Standard would not be applicable to the single-family residential project or the requirement would be an undue burden compared to the scale and impact of the project. In an effort to reduce the burden of the new regulations on single-family homeowners and encourage land use practices that meet RIDEM's stormwater treatment goals, Section 1.2 of the RISDISM (Applicability of the Manual) requires that the stormwater management standards and performance criteria be applied "to the maximum extent practicable for single-family lots of record". Reference is also provided to a "Small Sites Guide for Stormwater Management" developed for the State of Vermont.
Since the RISDISM has been promulgated, RIDEM has worked with the RI Coastal Resource Management Council ("CRMC") to develop guidance for single-family lots of record. It is expected that, for single-family lots of record (including both new homes and additions to existing homes), compliance with this guidance will satisfy the review standard of "to the maximum extent practicable" stated in Section 1.2 of the RISDISM. It has been written in a format that, with few exceptions, can be understood and followed by home-owners but that can also provide useful guidance for design professionals.
Accordingly, both DEM and CRMC will expect that all future applications for residential projects on single-family lots of record will, at a minimum, adhere to the new Rhode Island Stormwater Management Guidance for Individual Single-Family Residential Lot Development. All applicants may also elect to fully comply with all minimum standards and performance criteria outlined in the RISDISM if they wish, or utilize the RISDISM for further guidance.