Maine Stormwater Conference

Planning & Ordinance

Monday, November 16

Presentations from the 2015 Conference are available here.

10:00 – 11:30
Session I – Planning for $uccess

10:00 – 10:30
Envisioning Better Communities: Seeing More Options, Making Wiser Choices
Randall Arendt, Greener Prospects

This session describes and illustrates the conservation subdivision design technique (CD) as it has been applied in Maine. CD offers a perfect fit for addressing many stormwater concerns (improving watershed health, replenishing aquifers, reducing flooding, and avoiding streambank erosion), because it typically conserves half or more of the buildable land (plus all of undevelopable land). This technique is much easier to use than TDRs, often costs less to develop than conventional large-lot layouts, and does not require large public subsidies (such as are needed to purchase development rights). With CD, LID techniques are integrated into the site planning process from the start, where developments are specifically laid out around the open space which is delineated as the first design step. CD can also help towns preserve town-wide open space networks and to create greenways for both wildlife and trails. This session draws heavily on the brand-new, totally updated second edition of “Rural by Design: Planning for Town & Country”.

10:30 – 11:00
Plan to Save: Early adoption of enhanced local stormwater regulations could provide substantial cost savings in the Oyster River Watershed, NH
James Houle, University of New Hampshire Stormwater Center; Bill Arcieri, VHB

Municipalities and private landowners are likely to face a growing economic liability involved with meeting future stormwater management and Clean Water Act obligations. As the list of impaired water bodies continues to grow, state and federal regulators are moving towards more stringent requirements on regulated communities and private landowners to restore and/or meet water quality objectives and minimize the impact of land development activity. Various models and predictive tools are available to predict changes that estimate increases in pollutant loads as a result of future impervious cover changes. For this study, the Simple Method model as described in the NH Department of Environmental Services (NHDES) Stormwater Manual was used to predict future pollutant load increases as a result of potential increases in impervious cover. The pollutants evaluated in this study include total suspended solids (TSS), total phosphorus (TP) and total nitrogen (TN).

11:00 – 11:30
Going Green!  The City of Newburyport’s Plan for the Future
Jennifer Lachmayr & Kathryn Edwards, ARCADIS

The City of Newburyport has made a concentrated effort to implement holistic integrated water quality solutions City-wide, and green programs have become a priority for all involved in planning efforts. We will discuss data from a recent watershed study and the potential realistic green infrastructure improvements, illustrate how the goals of both reducing runoff volumes and improving water quality are met, and outline the City’s proposed implementation strategy, framework and costs for a green community.


1:00 – 2:30
Session II – Stormwater. Where is it going?

1:00 – 1:30
A Retrospective Assessment of Local LID Requirements in South Portland, ME
Fred Dillon & Steve Pueleo, City of South Portland, Maine

In April of 2009, the City of South Portland established local stormwater performance standards as required by Maine’s 2008-13 MS4 Permit. While the primary motivation for developing these standards was to maintain regulatory compliance, the City’s stormwater ordinance was also intended to manage runoff from development and redevelopment projects not covered under the State’s Chapter 500 stormwater management rules. Most development / redevelopment projects in South Portland with less than 1 acre of disturbed area are now required to use LID practices to manage the quantity and quality of stormwater runoff. Given all of these projects are subject to local review, the municipal planning process plays a crucial role in the City’s water resource protection and restoration efforts.

Since the inception of the City’s Stormwater Performance Standards in 2009, nearly 50 projects have been required to install some kind of stormwater treatment system. In addition to local review and approval, over half of these projects have also required approval from the Maine Department of Environmental Protection (MDEP). A careful examination of these projects provides important insights about the ordinance in relation to stormwater management costs, responses by the development community, and implementation challenges. Of particular note is the cost comparison between projects requiring only City approval and those also requiring DEP approval. Our analysis shows that treatment and maintenance costs are similar in both cases.

In Maine, there are currently 31 streams designated by the DEP as “urban impaired” due to the adverse and cumulative effects of surrounding development. Clearly, how and where development occurs is directly related to local water quality. While South Portland is approaching full build-out capacity, every new development or redevelopment project provides an important opportunity for increased water quality protection. Therefore, the City’s Stormwater Performance Standards may be instructive for other communities considering local LID ordinance requirements.

1:30 – 2:00

Ellsworth Rain Clouds Know No Boundaries
Michele Gagnon, City of Ellsworth, Maine

The sizing of culverts and other stormwater infrastructure “that works” is dependent on access to accurate rain data.  We know that the 100-year storm of the 1960s is not the same as the 100-year storm of today, but communities are still using outdated rain data to size stormwater infrastructure. Through its partnership with the Sustainable Solution Initiatives, Ellsworth now looks to regulate the sizing of stormwater infrastructure at the watershed level, therefore across jurisdictional boundaries, using accurate rain data. Other factors to be considered when developing stormwater regulations include the project’s location within a watershed and its potential impact on downstream build out, valuation, critical services, and population density.

2:00 – 2:30
Setting the Standard: Protecting Priority Watersheds and Encouraging Responsible Development 
Jennie Franceschi, formerly City of Biddeford, Maine

The City of Biddeford has successfully and proactively held their development review process to standards more stringent than DEP requires to proactively protect its priority watershed Thatcher Brook.  The process has been a collaborative one incorporating education on the effects of development on Thatcher Brook and the consequences of not being proactive.  This process involved City staffers, Planning Board Members, City Commissions, City Councilors and most importantly, the development community.  These efforts have shined a light on protection of Biddeford’s natural resources and the need to be mindful in responsible development.


3:00 – 4:30
Session III – Planning for Change

3:00 – 3:30
Examining Recent Temperature and Rainfall Trends in New England and Its Impact on Flood Frequency
David Vallee, NOAA/NWS/Northeast River Forecast Center

Much of New England has been experiencing an increasing trend in annual average temperature, annual average precipitation, and the number of heavy rainfall events over the past two decades.   During this same time period, the region has experienced an increasing number of moderate to major flood episodes.  These episodes have been associated with a variety of storm types and have affected the region at different times of the year.  The common thread in each episode was the ability of each storm system to tap a tropical moisture source which resulted in very heavy rainfall on already saturated ground.  This presentation will examine these observed climate trends, the atmospheric connections to the increased rainfall intensity of our weather systems, and the impacts it is having on river flood frequency in the region.

3:30 – 4:00
Integrating Storm Surge and Sea Level Rise Vulnerability Assessments and Criticality Analyses Into Asset Management at MDOT
Sam Merrill, GEI Consultants; Judy Gates, Maine Department of Transportation

Adapting infrastructure to increased water levels over time – whether from runoff from extreme weather events or coastal sources like sea level rise and storm surge – presents the need to evaluate cost-effectiveness of possible actions including upsized culverts, alternative bridge designs, road elevation, and many others. Unfortunately for both municipal planners and infrastructure managers, the most common approach is to simply pick an environmental condition to design for and hope the project will neither underbuild nor overbuild for what actually occurs in the future. However the risk of overbuilding and spending more than was necessary is very high, as is the risk of underbuilding and being vulnerable to catastrophic losses. This dilemma presents challenges for both comprehensive planning and capital investment planning – challenges exacerbated by longstanding schisms between the two realms. Dr. Merrill will describe a method that addresses these issues, show case studies of its use in transportation infrastructure settings, and explain how results of this type can help improve comprehensive planning processes.

4:00 – 4:30
Building Bath to Last: Considering Sea Level Rise when Designing the Future
Andrew Deci, City of Bath, Maine

Bath, Maine is confronting the challenge of a changing environment by considering rises in sea level and flooding and its impact on the community’s important downtown. The community participated in a pilot project of the American Institute of Architects, with the goal of understanding how urban design, policy, and architectural enhancements can help retain the unique character of the downtown over time. The project involved a cross disciplinary team from across the country, facilitating a quick public planning process. Over three days, the team developed a presentation and report that is now the foundation for future changes to insure Bath is Built to Last.


To view speaker bios click here.

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