New Hampshire’s Water Assets Under Pressure: Municipal Stormwater Systems

Timothy W. Fortier

This is the second of a four-part series focusing on the state’s water infrastructure: public drinking water, wastewater, storm water and dams. Each article will spotlight a municipal system; address critical needs of that infrastructure system; and outline funding sources available to municipalities today that may be used to maintain and sustain these critically important infrastructure systems.

Our water infrastructure systems are essential to public health and safety, economic growth and quality of life in New Hampshire. We have basic water infrastructure systems that go generally unnoticed by us—the consumers. We pour tap water into our glass and drink reassured that it is safe to drink. We flush our toilets and the waste simply vanishes. When it rains, contaminants are washed off rooftops, parking lots and streets, and this runoff is channeled through a series of catch basins, drains and underground pipes to places unknown. New Hampshire municipalities own nearly 400 dams statewide that provide recreational lakes, fire ponds, flood control and water supply storage. Yet the public pays very little attention to these basic water systems. That is, until a pipe bursts, the toilet clogs, the streets flood or, more tragically, a dam fails.

We hope that by highlighting these important water assets, ordinary citizens and policymakers alike will better understand the value these assets provide for the protection of public health and safety and in supporting economic growth and development in all 234 communities.

We also want to highlight the many challenges facing municipalities in maintaining the quality of these basic water infrastructure systems. Whatever infrastructure a municipality owns, the challenges are generally the same: (1) aging infrastructure systems that have not been consistently maintained due to funding shortfalls; (2) a continually evolving regulatory environment; and (3) declining state and federal funds that municipalities have historically depended upon to finance these capital improvements. A growing population and increasing demand has also put mounting stress on these water systems.

The second article in our series will focus on municipal stormwater systems.

Background: Municipal Stormwater Systems
Stormwater runoff is one of the fastest growing sources of water quality problems in New Hampshire. In fact, stormwater contributes to 83 percent of the surface water quality impairments in the state.

Stormwater is water from rainfall or snowmelt that does not soak into the ground, and as such contains air pollution and pollutants washed off from rooftops, paved areas (parking lots, sidewalks, driveways, developed commercial and industrial properties and streets) and heavily fertilized landscape areas (lawns, golf courses and agricultural operations). Stormwater from these developed areas can become polluted with high concentrations of surface water contaminants, including nutrients, bacteria, chemicals, sediments, cigarette butts, petroleum products, trash, pet wastes and heavy metals, among other pollutants. Typically, in undeveloped areas stormwater is not a problem because when rain and snow hit the ground, they soak into the soil below. This minimizes the amount of runoff and filters pollutants out through the soils naturally. When rain hits a less developed area, such as grassed or wooded areas, it has more time to flow over vegetated areas, slow down, and infiltrate into the ground. However, when rain hits impervious surfaces like parking lots and streets, it cannot soak into the ground. Instead, it becomes stormwater runoff and poses a greater problem to the water quality of New Hampshire’s surface and groundwater sources. (See Diagram 1)

Over time, the primary function of municipal stormwater systems has evolved from flood control to resource management with regulatory controls. This evolution has changed the way local government has managed its environmental responsibility. Some municipal systems manage stormwater runoff through a series of drainage networks, culverts, catch basins and underground pipes, often discharging it untreated back into rivers, lakes, wetlands and other waterways. A few municipalities reroute stormwater into the wastewater system and treat the stormwater the same way as sewage during low flow conditions. In any case, this evolution requires new or expanded funding sources for municipalities to support this long-term environmental responsibility.

According to Ted Diers, administrator of the Department of Environmental Services (DES) Watershed Management Bureau, the problem with the state’s existing stormwater infrastructure is three-fold. "First, like other water system infrastructure, many of the culverts, street drains, catch basins and outfalls are old and antiquated, especially in the more urbanized regions in the state. Digging up streets to repair and replace this old infrastructure is very costly."

"Secondly," continued Diers, “New Hampshire has experienced significant expansion of impervious surfaces, which increases stormwater volume. And lastly, changing precipitation patterns with more common extreme storms have begun to stress our existing stormwater infrastructure."

Historically, stormwater systems were designed to collect and quickly move runoff as a way to prevent localized flooding or erosion. Over time, it has become evident that the traditional curb-and-gutter approach was not sufficient. “We have learned over the past 20 years that the fundamental philosophy behind stormwater control needs to be changed. The focus of stormwater control has been reducing erosion by shunting water off streets as quickly as possible and detaining only the peak flow to avoid flooding," said Diers. "While this has reduced erosion, this approach speeds water velocities, changes natural hydrology, and delivers pollutants from streets to streams." 

New Hampshire’s Aging Infrastructure and Extraordinary Weather Events 
A typical stormwater infrastructure includes manholes, conveyances or pipes, discharge points, drains, culverts and catch basins. For example, the City of Dover’s stormwater infrastructure includes: 650 manholes, 65 miles of pipe, 204 discharge points, 101 miles of open drainage ditches, 140 culverts and 2,875 catch basins. Like other stormwater systems across the state, Dover’s system infrastructure is old and dates as far back as the late 1800s. To fund Dover’s future stormwater program needs, a 2010 feasibility study estimated an average annual cost of $2.7 million per year, for an average increase of $836,000 per year over currently budgeted costs.

The City of Manchester maintains over 170 miles of pipe, over 16,000 catch basins, many miles of open drainage ditches and hundreds of drainage outfalls. Manchester’s existing stormwater system represents an investment of over $135 million. According to a 2008 feasibility study, to properly maintain this large, aging and somewhat neglected infrastructure asset, a multi-million dollar annual budget would be required.

Like public drinking water systems, stormwater infrastructure is largely underground and invisible to the public. Stormwater rarely captures public attention unless it impacts the daily lives of citizens. Eric Williams, an administrator for the DES Water Division, refers to stormwater systems as the "forgotten infrastructure." To further exacerbate the problem, most municipalities lack adequate funding and have limited staff resources to support their stormwater program. "Stormwater management has historically struggled to compete effectively against other municipal needs or priorities. Because stormwater is not seen as an essential service, municipalities rarely prioritize stormwater planning and funding," said Williams.

Components of stormwater management are often embedded in a variety of municipal functions, including public works, engineering, street sweeping, transportation and wastewater treatment. For example, a public works department may manage culverts, storm drains and street sweeping, while the sewer department conducts catch basin inspections and detection of illegal discharges. 

"Stormwater management should be a part of an overall comprehensive approach to municipal infrastructure management," said Bill Brown, CEO and president of Wright-Pierce. "Undersized culverts are a good example of the need for communities to continually adapt existing municipal stormwater infrastructures."

Increasingly in New Hampshire, culverts are failing because of insufficient capacity for the increased flow of water coming from more development and associated impervious areas and extraordinary weather events. Acting as dams, undersized culverts cause water to backup and flood roadways. "The amount of rain we are currently experiencing far exceeds the design standards historically used by engineers to size stormwater conveyance systems," said Brown. “And it is comparatively less expensive for a municipality to adapt its existing infrastructure than to wait for a failure caused by a catastrophic weather event.”

Studies in New Hampshire have shown that the state’s existing drainage infrastructure is seriously undersized to accommodate the increases in storm intensity and frequency expected with changing weather patterns in the coming decades.

"Climate change will have a significant impact on our infrastructure systems, including stormwater," said Brown. "This trend toward unprecedented weather events will only increase the infrastructure funding challenges already faced by municipalities." 

In 2010, the State Legislature issued a final report studying stormwater management. The HB 1295 Commission concluded that while the financial cost of managing stormwater is high, the potential cost of inaction is even higher.

According to David Cedarholm, engineer with the Town of Durham and chair of the HB 1295 Commission, "Without new programs, new revenue sources, and a significant shift of thinking, municipalities will have a very tough time responding to the expectation of more extensive flooding and degradation of water resources." 

Among other findings, the HB 1295 Commission Report called for the creation of a statewide, watershed-based stormwater program with local options that could be phased in over a period of years.

Continually Evolving Regulatory Environment
At the local level, municipal ordinances and regulations control most of what happens with stormwater. Generally this is achieved only in new developments through zoning ordinance and site plan review. New developments can alter existing drainage patterns, including abutting properties, roadways and water bodies. Adopting a stormwater ordinance allows a municipality to act independently from state and federal officials to address any localized site concerns or water quality impacts. In fact, most local developments do not trigger state or federal stormwater oversight. 

According to Innovative Land Use Planning Techniques: A Handbook for Sustainable Development (October 2008), a performance-based approach to stormwater, authorized under RSA 674:21, allows a municipality to specify outcomes required by any new development activity without being overly prescriptive about the specific techniques or approaches used by developers to manage stormwater impacts. In this regard, municipalities can use a number of different techniques including conservation subdivision, lot size averaging, transfer of density credits and feature-based zoning. 

At the state level, development projects larger than 2.5 acres (less near water) are regulated by the Alteration of Terrain permit program. This permit requires some form of Low Impact Development (LID) technology to ensure that post-development runoff is managed appropriately.

"The emerging trend is toward Low Impact Development and other methods to infiltrate water, treat with Best Management Practices, and reduce direct connections to water bodies," said DES Stormwater Coordinator Jillian McCarthy. "The old stormwater infrastructure should be replaced with these green strategies in mind." LID methodologies attempt to avoid concentrated points of discharge by promoting infiltration and/or treatment with natural vegetation such as bio retention ponds, rain gardens, tree box filters, permeable pavers and green roofs.

"LID stormwater management works effectively throughout multiple seasons including challenging New Hampshire winter conditions," states Dr. Robert Roseen, director of the University of New Hampshire Stormwater Center and member of the HB 1295 Study Commission. "Data shows that LID technology works better for water quality than conventional stormwater management. Some studies have even shown LID to be more cost effective, and in some cases, result in significant cost savings," added Roseen.

Tom Irwin, vice president and director of the Conservation Law Foundation’s New Hampshire office, agrees with the benefits of emerging LID technologies. "The Environmental Protection Agency (EPA) has acknowledged that in its MS4 permitting program the 'maximum extent practicable' standard for controlling stormwater would be an evolving one—one that would benefit from a growing knowledge and development of best practices for stormwater management," said Irwin. "LID techniques have proven to be an invaluable stormwater management tool and, we believe, should be an important part of EPA’s MS4 permitting program."

At the federal level, stormwater pollution prevention plans (SWPPP) are required for any land disturbances greater than one acre under the National Pollutant Discharge Elimination System (NPDES) Construction General Permit. Additional regulatory requirements fall upon small municipal separate storm sewer systems, also known as "MS4s," under Phase II of the NPDES program, which is administered by the EPA. New Hampshire is one of only five states in which the EPA administers the NPDES program. (See System Spotlight)

Despite these protections at the state and federal level, many development projects disturb less than 50,000 square feet, and as such, local protection is critical. But just as no two communities are alike, there is no "one-size-fits-all" approach in addressing stormwater at the local level.

Declining State and Federal Funding Support
According to HB 1295 Report, the capital costs to properly manage stormwater in New Hampshire is estimated to be greater than $182 million, although most industry professionals agree the true costs  approach $1 billion. These costs include the costs to plan and implement structural and non-structural measures to control runoff water in NPDES Phase I and Phase II sources and non-traditional, unregulated sources.

New Hampshire municipalities fund their stormwater systems out of general fund or property tax revenues. This means that property owners pay for stormwater services based on the value of their property rather than the amount of stormwater generated on that property. In a typical community, commercial and industrial properties generate most of the stormwater impacts, but owners of residential property collectively pay more in taxes. More and more communities are concluding that the full costs of these impacts need to be better borne by the private sector in new development projects.

Although New Hampshire municipalities are authorized (Env-Wq 500) to make use of the State Revolving Fund loans financed by the EPA for the purpose of stormwater management, there continues to be less and less money available for this purpose. For example, State environmental aid to municipalities continues to shrink, from nearly $17 million in fiscal year 2007 to less than $6 million in fiscal year 2013. (See Diagram 2

In neighboring states, stormwater utilities have been formed to help raise local revenue to support a stormwater program. In 2008, the State Legislature enacted a law allowing New Hampshire municipalities to form stormwater utilities, but none have been formed to date. RSA 149-I enables municipalities to form and maintain stormwater systems and to establish special assessment districts to generate revenues specifically for stormwater management. Conceptually, users would pay a stormwater fee based on the percentage of impervious surfaces (i.e., parking lots, sidewalks, driveways, pavement, etc.) on their property. These fees would directly support the maintenance and upgrades of existing storm drain systems and other water quality programs that benefit the user. "By law, municipalities can develop and operate their own stormwater utility which would likely result in allocating user fees more equitably based on stormwater impacts emanating from each property. Neighboring municipalities can also band together to form an inter-municipal stormwater utility under RSA 149-I," said Rep. Judith Spang, a member of the HB 1295 Commission and ranking minority member of the House Resources, Recreation and Development Committee. "Unfortunately, the current economic climate and lack of adequate funding from existing sources leaves little or no funding available for stormwater management at both the state and local level," said Spang.

A user fee is only one way to generate local revenues to support a stormwater program. Other funding sources include available federal and state grants and loans, bonding, service fees, impact fees, application and inspection fees and special assessments. Depending on the revenue source, each has different implications in terms of who will pay, how the money will be collected, and how the money can be spent.

Local governments recognize their responsibility for urban flood control and clean-up of the contaminants and pollutants caused by stormwater runoff. However, while municipalities support environmental protection, they struggle with stringent permit requirements, escalating costs and tight deadlines. Most municipalities today are facing significant funding challenges, including a lack of adequate staff resources, to meet these evolving regulatory requirements.

"While the monetary cost of managing stormwater is high, the potential cost of inaction is even higher," argued Roseen. "Without significantly changing our approach to stormwater, New Hampshire will likely experience even more extensive flooding and degradation of water resources that will impact drinking water quality, aquatic habitat, recreational opportunities and tourism."

As we move forward, municipal stormwater systems will need to have flexibility in adjusting to changes in weather patterns, regulations, legislation, public demands and court decisions. If long-term management of stormwater is to be effective, new funding mechanisms and a new way of thinking about stormwater systems are important considerations for state policymakers to consider. This will certainly require more public education about the stormwater issues facing municipalities today.

Tim Fortier is Government Affairs Advocate for the New Hampshire Municipal Association. Contact Tim at 800.852.3358, ext. 384, or email

System Spotlight: New Hampshire’s ‘MS4’ Communities

The Clean Water Act prohibits the discharge of pollutants from point sources, such as treated wastewater, process water or stormwater, into surface waters unless specifically authorized by a permit. When first established in the early 1970s, the National Pollutant Discharge Elimination System (NPDES) program was intended to regulate only wastewater treatment plant and industrial facility discharges, however, Congress expanded the NPDES program to cover stormwater discharges in 1987. The long-term goal of the Clean Water Act is the complete elimination of polluted discharges to surface waters, hence the program’s title, the National Pollutant Discharge Elimination System.

On April 18, 2003, a NPDES stormwater permit, also known as the Small Municipal Separate Storm Sewer Systems or "MS4" permit, was issued to New Hampshire from the EPA. The permit applied to all "publicly-owned conveyances" that divert stormwater into the surface waters of the state and within an "urbanized area," defined as a place or places with a residential population of at least 50,000 and an average density of at least 1,000 people per square mile. New Hampshire has 45 municipalities that are partially or fully regulated under EPA’s MS4 permit program.

Just because a municipality is not currently regulated under EPA’s MS4 permit program, doesn’t mean it won’t happen. According to CLF’s Irwin, "The Clean Water Act provides the EPA with so-called ‘residual designation authority,’ which makes it possible for EPA to regulate municipalities or other dischargers that otherwise may not be subject to existing regulatory programs. EPA has exercised this authority, for example, by addressing stormwater pollution from commercial land uses in the lower watershed of the Charles River in Massachusetts."

Under the 2003 permit, municipalities are required to implement a Stormwater Management Program that controls pollutants to the "maximum extent practicable." The 2003 permit mandated certain requirements, including adoption of stormwater controls, regulations and public education. Outreach campaigns typically mark catch basins with colorful logos to educate the public about where the stormwater flows.

Under its own terms, the NPDES permit issued by EPA to New Hampshire expired in 2008. However, the EPA can "administratively continue" the permit by regulation, and as such, the state continues to operate under the 2003 permit terms. The next permit, issued as a draft on June 20, 2008, is a source of controversy between regulated MS4 municipalities and the EPA. Local officials have protested against the draft permit, claiming that it will require expensive upgrades without any significant source of federal or state funding to produce marginal improvements in water quality.

Numerous local officials representing the cities of Somersworth, Rochester, Portsmouth and Nashua, have voiced their strong concern to EPA regarding the draft 2008 permit, in large part, due to its overly prescriptive requirements and the costs associated with it. Local officials argue that in this era of limited revenues, most communities are scaling back on the delivery of essential services, including stormwater infrastructure-related expenses.

"The city of Portsmouth estimated that cost of compliance with the 2008 draft permit requirements would add $1 million a year in new costs to our public works budget at a time when the city was working toward a zero-based budget increase," said Peter Rice, city engineer. "The 2008 permit requirements are purely administrative. There is no new pipe, no new infrastructure and little, if any, benefit to the environment."

Specifically, local officials expressed disagreement with some of the requirements outlined in the 2008 draft permit, including: (1) addressing water pollutants that are a result of airborne transport, such as mercury in the Salmon Falls River in Somersworth; (2) addressing the lack of legal authority to request private property owners to report how much salt they use; (3) concern regarding reliance of homeowners to maintain systems in low impact developments as unenforceable or impractical; and (4) requiring sampling of every outfall during wet and dry weather conditions as overly burdensome and unnecessary.

Under the 2008 draft permit, MS4 municipalities will be required, based on calculations provided by the EPA, to estimate the number of acres of impervious area and directly connected impervious area that have been added or removed each year due to development or redevelopment. Once a baseline has been established, the municipality must then annually track the changes in these areas. Again, these new regulations come without any federal or state funding assistance. Despite the fact that local officials may object to these environmental mandates, they have no realistic alternative but to pay for them.

"There needs to be a better understanding that stormwater is a problem," said Rice, "but the public doesn’t understand that stormwater is a very costly environmental responsibility for municipalities."

Additional Resources

Find links to these and other resources online at

HB 1295 Stormwater Commission Final Report
Stormwater Management Model Ordinance
Innovative Land Use Planning Techniques Handbook
New Hampshire Water Resource Primer
New Hampshire Stormwater Manuals, Volume I and Volume II
RSA 149-I
List of ‘MS4’ Communities

Sources and Author Acknowledgements
Special credit and recognition to New Hampshire Department of Environmental Services (DES) Administrator, Watershed Bureau, Ted Diers; Assistant Administrator Eric Williams; and Stormwater Coordinator Jillian McCarthy. Wright-Pierce CEO and President Bill Brown devoted time peer reviewing this article and providing company expertise on the subject matter.

Valuable input and contributions also from: David Cedarholm, public works director for Town of Durham; Representative Judith Spang; Dr. Robert Roseen, director of the UNH Stormwater Center; Tom Irwin, vice president and director of the Conservation Law Foundation; and Peter Rice, engineer with the City of Portsmouth.

This article cites extensively from the Municipal Stormwater Utility Feasibility Study prepared by GHD, dated December 2010; Final Report of Stormwater Feasibility Study prepared by Hoyle, Tanner & Associates, Inc., dated June 2008; New Hampshire Stormwater Manual, Volume I, dated December 2008; State of the Cities, The Association of Washington Cities, 2011 Report. Additional information for this article also gleaned from the DES website, including fact sheets and other informational materials on the topic.