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Table of Contents: Keywords: Ipswich River, instream flow, Water Management Act, Interbasin Transfer Act, water withdrawals, interbasin transfers, aquatic habitat |
 Three more months of summer to go - Photos by Dave Armstrong |
Concern for the ecological integrity of Massachusetts rivers has typically focused on water quality issues. Since the passage of the federal Clean Water Act (Public Law 92-500) in 1972, great effort and considerable expense has been spent to reduce pollution discharges into Massachusetts rivers. Water quality in many of the state’s rivers has improved considerably. Unfortunately, the Clean Water Act, which has the stated goal to “restore and maintain the chemical, physical, and biological integrity of the Nation's waters,” does not address the need to maintain adequate instream flows to support a healthy aquatic community. As a result, this aspect of aquatic habitat protection has not received adequate attention or regulatory protection. Many Massachusetts rivers and streams are suffering from a lack of concern about restoring and maintaining instream flow.
 Photo Credit - R. Stevenson |
Although low flow problems have been identified in several river basins, most notably in the Ipswich River in northeastern Massachusetts, efforts to assess stream flow problems on a statewide basis have only recently been initiated. Beginning in 1999, an interagency committee convened by the Massachusetts Water Resources Commission (WRC) examined flow trends in Massachusetts rivers and streams as part of an effort to identify hydrologically-stressed river basins and sub-basins. This analysis included the development of flow stress classifications for 72 river or stream reaches in Massachusetts where long-term flow data has been recorded by United States Geological Survey (USGS) stream gages. The findings and recommendations resulting from this analysis, which were approved in late 2001 by the WRC, classify river and stream reaches where USGS flow gage data is available by level of hydrologic stress and will be used to guide environmental permitting and planning (Massachusetts Water Resources Commission, 2001). In 2002, the Massachusetts Riverways Program collected data on documented and reported low flow problems in Massachusetts rivers and streams and created a Low Flow Inventory posted on the Riverways Program website (Massachusetts Riverways Program, 2002).
 High and Dry - Photo by Mary Jane Morrin |
Regional sewer and water systems serve many communities in Massachusetts and frequently transfer water and wastewater across watershed boundaries. The largest of these systems, operated by the Massachusetts Water Resources Authority (MWRA), serves more than 40 communities in eastern Massachusetts. The MWRA transports eastward each day approximately 255 million gallons of water from the Ware, Swift and Nashua river systems of central Massachusetts to meet the needs of eastern Massachusetts communities. After this water is used and discharged to municipal sewers, it is collected and treated by the MWRA at the Deer Island Wastewater Treatment Plant in Boston and discharged to Boston Harbor, approximately 30 miles from the nearest source watershed. In addition to the MWRA, many smaller regional water and sewer systems in Massachusetts also transfer water across watershed borders.
Because political boundaries seldom conform to watershed boundaries, even water and sanitary sewer systems serving a single community may transfer large volumes of water across watershed boundaries, altering the hydrology of both the donor and receiving watersheds. Conventional sanitary sewer systems have another characteristic that also plays a major role in altering watershed hydrology. These sewers tend to leak. This can result in the infiltration of large volumes of groundwater into the sewer during periods of the year when groundwater levels are above the elevation of the sewer pipe. During storm events, large amounts of stormwater may also be directed into sewers. The discharge of stormwater to sanitary sewers, called inflow, is often by design in older sewer systems. In newer systems, it occurs either by accident, as a result of deterioration in the structural integrity of the sewer system, or due to illegal connections when sump pumps, yard drains, and roof drains are discharged to the sewer. In some sewer systems, as much as half the annual flow volume consists of infiltration and inflow. The infiltration of groundwater into sanitary sewers lowers groundwater levels and reduces the amount of groundwater available as base flow in rivers and streams during dry summer months. Because sewer systems are designed to operate by gravity flow, groundwater is typically removed from upper areas of watersheds and transported in sewers to treatment plants located downstream, effectively short-circuiting the natural hydrology of the watershed.
Recent patterns of development are also having significant impacts on flows in Massachusetts rivers and streams. While state and federal legislation mandating the use of more efficient plumbing fixtures have helped to restrain indoor water use in some communities, outdoor water use for lawn irrigation continues to grow. The trend in many suburban areas in recent years has been towards a residential development pattern of large lawns irrigated with automatic in-ground sprinkler systems. Communities experiencing this type of development often find water use doubling or tripling during summer months (Massachusetts Water Resources Commission, 2002). Many of these communities draw their public water supplies from high-volume wells located along rivers or streams. Pumping of these wells intercepts groundwater that otherwise would discharge to the watercourse as base flow, helping to maintain streamflow in summer. This pattern of water use poses a particular threat to rivers and streams because it results in the largest volume of water withdrawal during the summer, at the same time instream flow typically reaches it lowest annual level.
Watershed development poses a number of threats to instream flow, including increased water withdrawals as population and the area of irrigated turf and other plantings increase, the spread of conventional sewer systems, and an increase in the amount of impervious surface. As development increases, impervious surface in the form of roads, parking lots, driveways, and buildings also increases. Increased impervious surface results in increased stormwater runoff and reduced infiltration of precipitation into the soil to recharge groundwater. This leads to reduced base flow to support stream flow in summer, as well as increased flooding during storm events and increased transport of sediments and pollutants into waterways.
 River in Sad Shape; No Sign of Life - Photo by Kerry Mackin |
The Water Management Act (WMA) was passed in 1985. The WMA regulates water withdrawals and empowers the Massachusetts Department of Environmental Protection (DEP) with the authority to grant or deny permits for surface or groundwater withdrawals. The DEP is also required to establish conditions in the water withdrawal permits it issues to protect instream flows and fish and wildlife habitat (310 CMR 36.00). Currently, permits are required for any water withdrawal volumes in excess of 100,000 gallons per day (gpd), although the Act gives DEP the authority to regulate smaller volumes.
A significant limitation to the effectiveness of the ITA and the WMA for restoring stream flow is the exemption from regulation of water transfers and water withdrawals in effect at the time of the passage of these statutes. In the Ipswich River watershed most of the water withdrawals and interbasin transfers that severely deplete summer stream flow were already in place at the time the ITA and WMA took effect. Both the ITA and WMA are relatively new and the policies and practices used by state agencies to interpret and implement these statutes have changed over time. New methodologies have been developed for estimating municipal water supply and instream flow needs, the emphasis on water conservation has been increased, interbasin transfer standards have been developed, and details of the permitting and review process have been revised. In spite of these changes, the manner in which the statutes are interpreted and applied remain an issue of contention between agency staff, conservationists, and permit holders and applicants.
The Ipswich River is perhaps the most seriously flow-impaired river in Massachusetts. In 1997, the river advocacy organization, American Rivers, designated the Ipswich River one of the 20 most threatened rivers in North America (American Rivers, 1997). The Ipswich river drains approximately 155 square miles in 22 cities and towns before discharging to the Atlantic Ocean. In general, the eastern portion of the upper watershed in the towns of Burlington, Wilmington, and Reading, and the southern edges of the watershed are more densely developed than the central, lower, and northern portions of the watershed. Estimates of land use in the watershed in 1991 vary, but have been reported as approximately 40% forest and open space, 35% residential development, 20% wetlands, and 5% commercial development (Horsley & Witten, 2002).
Two USGS stream flow gages measure flows in the Ipswich River. A gage at South Middleton measures flows from the uppermost 44.5 square miles of the watershed. A second gage in Ipswich measures flows from 125 square miles of watershed. The South Middleton gage has been in operation more or less continuously since 1938, the Ipswich gage since 1930. Data from these two gages provide a relatively long history of flows in the river. Mean annual streamflow is 41 million gallons per day (mgd) at South Middleton and 122 mgd at Ipswich. The Ipswich is a low-gradient river, dropping only about 110 feet between its headwaters and its discharge point at Ipswich (Zarriello and Ries, 2000).
The Ipswich River watershed serves as a source of public water supply for approximately 330,000 people in fourteen communities, including three with a combined population of 165,000 (Beverly, Salem, and Lynn) that are located primarily or entirely outside of the watershed. According to annual water supply statistical reports filed with the Massachusetts DEP, these communities used an average of approximately 40 mgd of water in 2001. Approximately 70 percent of this water was drawn from the Ipswich River watershed (Mackin and Wagner, 2002). Four communities -- Beverly, Lynn, Salem, and Peabody -- divert water directly from the river to storage reservoirs from December through May. Two communities that share a public water system -- Danvers and Middleton -- use a combination of groundwater wells adjacent to the river and a reservoir on a stream tributary to the Ipswich River. The remainder of the communities take water from wells located mostly in the Ipswich watershed. Some of these wells are located directly adjacent to the main stem of the river or its tributaries.
A number of the communities that take a water supply from the Ipswich River watershed are served by regional sanitary sewer systems that discharge treated wastewater outside of the watershed. The combined water withdrawals of the communities that discharge wastewater outside the Ipswich watershed, as reported to the Massachusetts DEP, amounted to approximately 22 mgd in 2001. The combination of large-scale water withdrawals, interbasin transfers, and to a lesser degree, stormwater runoff from increasing imperviousness associated with watershed development in the upper portions of the Ipswich watershed have combined to dramatically reduce instream flows in the upper Ipswich River during summer months. As a result, extreme low flows and the drying up of portions of the upper Ipswich River and tributary streams occurred in 1995, 1997, 1999, and 2002.
 The Ipswich River in the vicinity of the Town of Reading municipal wellfield, September 12, 2002. Substantial fish kills occurred in this area in 2002 and previous years. The size of the fish killed has diminished over the years. In 2002 none exceeded 10 cm in length. |
The Ipswich River in the vicinity of the Town of Reading municipal wellfield, September 12, 2002. Similar conditions developed in this area during the summers of 1995, 1997, and 1999. Investigations by the United States Geological Survey directly linked these conditions to groundwater withdrawals from municipal water supply wells. |
| Photos by Lou Wagner | |
In 1996, the Ipswich River Watershed Association (IRWA) convened the Ipswich River Task Force, an ad hoc group comprised of conservationists, municipal officials, state and federal agency personnel, and other interested parties, in an effort to address the low flow problem and restore the river. The task force drafted and adopted the following mission statement:
“The goal of the Ipswich River Basin Task Force is to ensure the protection and management of Ipswich River Basin water resources to preserve the ecological integrity of the river and its watershed, including the restoration of historic fisheries, and to maintain a safe and sustainable supply of water for human uses, including public and private water supply and recreation. Essential to achieving this goal is the development of a better understanding of the hydrology and ecology of the Basin and the promotion of regional cooperation between stakeholders.” (Ipswich River Basin Task Force, 1996)
Fundamental to accomplishing this mission was the development of an understanding of watershed hydrology and the causes of the low flow problem. In 1996, representatives of a number of the municipalities that take water from the Ipswich watershed held the view that the low summer flows were simply natural characteristics of the watershed itself and were not caused by water withdrawals, interbasin transfers, or other anthropogenic factors. Conservationists countered that there was a direct link between water withdrawals and interbasin transfers and the apparent increasing frequency of portions of the river and tributary streams in the upper half of the watershed to experience extreme low flows or dry up in summer. Two fundamental questions stood in the way of serious efforts to protect and restore flows in the Ipswich River:
1) why do large portions of the river run dry approximately every other summer? and,
2) how much flow is needed to support a healthy aquatic community in the Ipswich River?
The Ipswich River Task Force worked with state agencies to secure funding to answer these questions.
In 1997, the USGS began work on a hydrology model of the upper Ipswich watershed (Zarriello and Ries, 2000). The completed model demonstrated a direct connection between groundwater withdrawals in the upper watershed and the length and severity of low and no-flow events in the upper reaches of the river. The results showed that groundwater withdrawals increased the severity of low flow and no-flow conditions by approximately an order of magnitude. In subsequent investigations, USGS used the hydrology model to evaluate the potential effects of reduced seasonal water withdrawals and the return of treated wastewater currently exported from the watershed by upper basin communities (Zarriello, 2002a). These alternative water management scenarios indicated that reduced seasonal water withdrawals could reduce the frequency of seven-consecutive-day low flow periods from approximately every year to every other year in a critical habitat reach of the river in the upper watershed. Return of treated wastewater was found to have an even more significant effect on reducing the frequency of seven-consecutive-day low flow periods and could restore river flows to the levels that the model predicted were in existence prior to the development of the watershed.
In 1998 and 1999, the USGS and the Massachusetts Division of Fisheries and Wildlife conducted an assessment of habitat, fish communities, and streamflow requirements for habitat protection in the Ipswich River (Armstrong, Richards and Parker, 2001). This study reported that in years of adequate sustained streamflow, the Ipswich River contains diverse and high quality fish habitat. The best fish habitat was found along stream margins, but in summers of low flow, these areas become unavailable. Fish sampling was conducted at 27 sites on the mainstem of the Ipswich River in 1998 and 10 sites on major tributaries in 1999. The study revealed a warm water fish community largely composed of species typical of ponds. Dominant fish species were Redfin pickerel (Esox americanus), American eel (Anguilla rostrata), and pumpkinseed (Leptomis gibbosus); combined, these species represented 73 percent of the fish sampled. Few fluvial-dependent or fluvial-specialist fish were found, but the authors concluded that habitat conditions indicated that the Ipswich River could potentially support cold-water fish species if adequate flows were maintained. In comparison to a nearby, reference fish community in the Lamprey River in New Hampshire, the Ipswich was found to have far fewer fluvial-dependent and fluvial-specialist fish than expected.
The USGS aquatic habitat study identified four riffle sites on the mainstem Ipswich River as critical habitat due to the tendency of these sites to be the first areas of the river to go dry when flows decline. Four habitat assessment methods (Tennant, Aquatic Base Flow, Wetted-Perimeter and R2Cross) were used to determine the minimum streamflow required at these riffles to maintain good fish habitat. The results of minimum streamflow assessments using each of these four methods were averaged to recommend a single minimum streamflow of 0.42 cubic feet per second per square mile (cfsm). Because the four riffle sites are the first places to dry as flows drop, this minimum flow was deemed adequate to maintain good fish habitat in most of the mainstem river.
The USGS hydrology model and aquatic habitat studies provided scientific answers to the two questions that had stymied restoration efforts when conservationists and municipal officials were fighting over the fate of the Ipswich River. The model demonstrated that groundwater withdrawals and the subsequent transfer of water out of the watershed after use was the cause of the frequent low flow and no-flow events in the upper reaches of the Ipswich River. The habitat study established the flows needed to protect habitat quality and support a healthy river fish community. The USGS performed several additional studies utilizing the hydrology model to assess the effects of wastewater returns and reduced water withdrawals in the upper watershed (Zarriello, 2002a) and the effects of maintaining minimum streamflows on the safe yield of the surface water supplies used by Beverly, Salem, Lynn and Peabody (Zarriello, 2002b). These studies provided insight on the relative effectiveness of various restoration measures and the effects of restoring instream flow on the capacity of municipal water supply systems.
An Ipswich River watershed management plan, funded by the Massachusetts Executive Office of Environmental Affairs, was completed late in 2002 (Horsley & Witten, 2002). This plan brought together the results of the studies conducted by USGS and identified management options for restoring river flows while meeting human water needs. Management options evaluated include water conservation, stormwater management, alternative sources of water supply, increased water storage to reduce summer pumping of riverside wells, alternative wastewater management approaches to reduce the export of wastewater from the watershed, and land use planning to minimize any future increase in water demands associated with new development.
Late in 2002, the Massachusetts DEP announced preliminary plans for revising the WMA water withdrawal permits held by the municipalities that take water from the Ipswich River watershed. Water withdrawal permits are issued for a period of 20 years, with regular reviews and revisions nominally scheduled at five-year intervals during the permit period. The Ipswich permits were first issued in 1989, but have been reviewed and revised only once since that time. DEP has stated that it placed the second five-year review, scheduled for 1999, on hold awaiting a reliable basis for action based on the findings of the USGS studies (Massachusetts Department of Environmental Protection, 2002). When the permits were originally issued, the volumes of water that municipalities were authorized to withdraw from the Ipswich watershed were based on the projected water use of those communities with little assessment of the effects of the water withdrawals on aquatic habitat, recreational uses, or other river values.
In its announcement of plans to revise the Ipswich water withdrawal permits, DEP indicated a commitment to using the information on the impacts of groundwater withdrawals and interbasin transfers on river flow and aquatic habitat provided by the recent USGS studies to guide the development of permit conditions and water withdrawal allocations. DEP also incorporated recommendations from a task group of fisheries experts convened by IRWA to identify minimum year-round flows necessary to restore a healthy community of river fish in the Ipswich River (Ipswich River Fisheries Restoration Workgroup, 2001). DEP is requiring the municipalities that hold water withdrawal permits in the Ipswich watershed to evaluate their ability to achieve the following stream flow thresholds in the Ipswich River:
June – October 0.42 cfsm
November – February 1.00 cfsm
March – April 2.50 cfsm
May 1.50 cfsm
The results of these evaluations are due to be completed and reported to DEP in March, 2003. DEP has asked municipalities to address the feasibility of a 20 percent reduction in summer water use from 1999 water use volumes, the implementation of water use restrictions tied to streamflow thresholds, new water rate structures designed to encourage water conservation, and measures to restore streamflow by increasing wastewater returns and reducing stormwater runoff in the watershed. DEP has stated its intention to issue revised permits in May, 2003.
The success of efforts to restore flows in the Ipswich River is far from assured. Massachusetts DEP will be under intense political pressure from the municipalities that take water from the Ipswich watershed to not significantly reduce the current levels of water withdrawals. Any significant reduction or restriction on current water withdrawals will likely result in administrative appeals and legal challenges from those who hold water withdrawal permits. At best, restoration will be a slow process as water conservation measures are implemented, alternative water supplies are developed, transfers of water and wastewater out of the basin are reduced, and stormwater management measures are adopted.
It will take many years to restore flows in the Ipswich River, but there are reasons for optimism and useful lessons to be learned from the Ipswich case. Progress in restoring the Ipswich can be attributed to two important factors. First, the keystone of success has been tenacious advocacy for flow restoration by IRWA and others, beginning with the convening of the Ipswich River Basin Task Force in 1996 and continuing to this day. Second, early and continuous commitment to developing a clear understanding of the causes and effects of low flows in the Ipswich River has provided a strong scientific foundation for flow restoration. In the Ipswich watershed, strong advocacy was necessary to secure the funding to conduct the scientific studies needed to understand the causes of low flows and the measures necessary to restore flows and a healthy fish community. This combination of advocacy and science offers an effective model for restoring and protecting flows in rivers across Massachusetts and nationwide.
You can learn more about the Ipswich River and Parker River at the following websites:
http://www.ipswichriver.org/conservation.html
American Rivers. 1997. Most Endangered and Threatened Rivers in North America. http://www.amrivers.org/mostendangered/1997report.htm
Armstrong, D.S., T.A. Richards and G.W. Parker. 2001. Assessment of habitat, fish communities, and streamflow requirements for habitat protection, Ipswich River, Massachusetts, 1998-99. USGS Water-Resources Investigations Report 01-4161. U.S. Department of the Interior, U.S. Geological Survey. Northborough, MA. http://ma.water.usgs.gov/publications/wrir/wri014161/reportbody.pdf
Horsley & Witten, Inc. 2002. Ipswich river watershed management plan. Barnstable, MA. http://www.horsleywitten.com/ipswich.html
Ipswich River Fisheries Restoration Workgroup. 2002. Ipswich river fisheries, current status and restoration approach. Ipswich River Watershed Association. Ipswich, MA. http://www.ipswichriver.org/FishRestReport.pdf
Ipswich River Basin Task Force. 1996. Goal statement and tasks.
Mackin, K. and L. Wagner. 2002. Ipswich River Basin Water Conservation Report Card. Massachusetts Audubon Society. Lincoln, MA. http://www.massaudubon.org/PDF/News/ipswich_riv_rep.pdf
Massachusetts Riverways Program. 2002. Massachusetts Executive Office of Environmental Affairs. Boston, MA. http://www.state.ma.us/dfwele/river/rivLow_Flow_Inventory/home.html
Massachusetts Water Resources Commission. 2002. Guide to lawn and landscape water conservation. Massachusetts Executive Office of Environmental Affairs. Boston, MA. http://www.state.ma.us/envir/mwrc/pdf/LawnGuide.pdf
Massachusetts Water Resources Commission. December 13, 2001. Stressed basins in Massachusetts. Massachusetts Executive Office of Environmental Affairs. Boston, MA. http://www.state.ma.us/dem/programs/intbasin/stressed_basins.htm
Massachusetts Department of Environmental Protection. 2002. Restoring the balance: Water Management Act permits in the Ipswich River basin. (memo to Ipswich River Watershed Council dated November 27)
Zarriello, P. J. 2002a. Effects of water management alternatives on streamflow in the Ipswich River basin, Massachusetts. USGS Open-File Report 01-483. U.S. Department of the Interior, U.S. Geological Survey. Northborough, MA. http://water.usgs.gov/pubs/of/ofr01483/
Zarriello, P. J. 2002b. Simulation of reservoir storage and firm yields of three surface-water supplies, Ipswich River Basin, Massachusetts. USGS Resources Investigations Report 02-4278. U.S. Department of the Interior, U.S. Geological Survey. Northborough, MA. http://ma.water.usgs.gov/publications/wrir/wri024278/default.htm
Zarriello, P. J. and Ries, K.G., III. 2000. A precipitation-runoff model for analysis of the effects of water withdrawals on streamflow, Ipswich River basin, Massachusetts. USGS Water Resources Investigations Report 00-4029. U.S. Department of the Interior, U.S. Geological Survey. Northborough, MA. http://water.usgs.gov/pubs/wri/wri004029/
The views and opinions expressed in all articles that appear in "Conservation Perspectives" are those of the authors and do not necessarily reflect those of NESCB.