DOCSLIB.ORG

Suncook River and Leighton Brook Basis of Design

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Suncook River and Leighton Brook Basis of Design Inter-Fluve, Inc. Technical Memorandum T O : Steve Landry, NH DES; Shane Csiki, NHGS F ROM: Nick Nelson, Inter-Fluve D ATE: April 26, 2013 R EGARDING: Basis of Design Memo for the Stabilization of the Suncook River - 90% complete designs Contents Introduction ..................................................................................................................................... 2 Alternatives Analysis and Impact to Regulated Resource Areas ............................................ 2 Background ..................................................................................................................................... 9 Existing Studies ............................................................................................................................ 11 Survey ........................................................................................................................................... 12 Hydrology ..................................................................................................................................... 14 Hydraulics ..................................................................................................................................... 15 Design ........................................................................................................................................... 19 Second Riffle Downstream of Rt 4 ........................................................................................... 21 Avulsion Site: Lag Deposit ~1000 feet Upstream of the Avulsion .......................................... 30 Leighton Brook ......................................................................................................................... 33 Channel Plan Form and Profile ............................................................................................. 34 Cross Sectional Geometry..................................................................................................... 36 Bed and Bank Materials ........................................................................................................ 40 Buttress ................................................................................................................................. 41 References ..................................................................................................................................... 47 Cost Estimate ................................................................................................................................ 48 Appendices A-E follow the cost estimate: Appendix A: Wetland delineation field maps and notes. Appendix B: Task 4 Technical Memo. Appendix C: USGS StreamStats information. Appendix D: Comparison of hydraulic cross sections between Inter-Fluve model and USGS model. Appendix E: 2011 Structural Assessment Technical Memo. 2013 Inter-Fluve, Inc. Suncook River, Epsom, NH 1 Introduction Inter-Fluve was contracted by the New Hampshire Department of Environmental Services (NH DES) to design and permit the restoration of the Suncook River in Epsom, NH. In 2006, a large flood event on the Suncook River resulted in a channel avulsion between the Huckins Mill Dam and the Rt 4 Bridge. This avulsion caused the abandonment of the primary and secondary channels and created a new channel to the east of Bear Island. The Suncook River is continuing to adjust to its shorter channel length by migrating laterally and incising. The incision is highlighted by a series of knickpoints that are migrating upstream on the Suncook River and its tributaries, primarily the Little Suncook River and Leighton Brook. The goal of this project is to limit further incision and excessive bank erosion in the vicinity of these knickpoints, in tributaries, and along the Suncook River upstream of the project site. Stabilizing vertical and lateral erosion will serve two primary purposes. First, stabilization will reduce the risk of the Rt 4 Bridge over the Suncook River and the Black Hall Rd culvert at Leighton Brook from being undercut by these migrating knickpoints. Second, stabilization will limit the further loss of wetland habitat, which would occur as incision moves upstream and changes the local water table elevations adjacent to the stream, and degradation of water quality, which could occur as a result of excessive erosion and downstream migration of sediment. Alternatives Analysis and Impact to Regulated Resource Areas A few alternatives to achieve the goals identified above were assessed during the design process. These alternatives include: do nothing, stabilize the channel bed and banks (chosen alternative as described in this report), replace the Rt. 4 Bridge and do no stabilization on the Suncook River, construct a valley-spanning grade control riffle downstream of the Rt. 4 Bridge, and place rock buttresses downstream of the Rt. 4 Bridge and the Black Hall Rd culvert. Alternative 1: Do Nothing Completing no work on the Suncook River or Leighton Brook could result in the undermining of bridge infrastructure (Rt. 4 Bridge on the Suncook River and the Black Hall Rd culvert on Leighton Brook), which could cause risk to human life and/or infrastructure. The Suncook River has eroded vertically and laterally since the avulsion occurred, and the vertical erosion is currently stalled at a series of cobble/boulder lag deposits that form riffles upstream of the avulsion site and downstream of the Rt. 4 Bridge. Because of the incision that has already 2013 Inter-Fluve, Inc. Suncook River, Epsom, NH 2 occurred, the abandoned railroad bridges (snowmobile bridges) over the Little Suncook River and Leighton Brook were undermined and have collapsed. A temporary bridge was built over Leighton Brook, but the bridge over the Little Suncook River has not been replaced. Site investigations revealed that the Suncook River is capable of eroding through the lag deposits and hydraulic modeling revealed shear stresses that could mobilize even the larger rocks in these lag deposits (see discussions of shear stresses below and the 2-Dimensional Hydraulic Modeling Report submitted in March, 2012). Further incision and bank erosion would result in further loss of agricultural land and likely damage to utility poles (west side of channel downstream of the Rt. 4 Bridge), roads, and private buildings. Continued incision and bank erosion along Leighton Brook could cause similar types of damage and risk to human life and infrastructure. A temporary snowmobile bridge over Leighton Brook is currently showing signs of erosion and this would only likely continue if no stabilization measures were taken. Buildings on either side of Leighton Brook are within 5-15 ft of the channel and could be undermined and damaged if erosion continues. Black Hall Rd could be undermined if the knickpoints that are throughout Leighton Brook continue to migrate upstream. In addition to potential damage to human life and infrastructure, doing nothing to stabilize the Suncook River and Leighton Brook would result in further loss of wetland habitat and degradation of in-channel habitat and water quality. Prior to the avulsion, Leighton Brook was a low-gradient stream that flowed through an extensive wetland before joining the Suncook River. When the avulsion occurred, nearly 1,000 ft of Leighton Brook channel and multiple acres of wetland were lost because of the migration of the Suncook River and the lowering of the water table. While portions of the wetland remain classified as a wetland adjacent to the existing mouth of Leighton Brook, the land surface here is approximately 20 ft above the channel elevation. Over time, the lowering of the water table at this location will likely result in a change in wetland classification. This type of ecosystem change could occur elsewhere along the Suncook River and tributaries without vertical and lateral stabilization of the Suncook River. Of particular concern is the large wetland complex on either side of the Little Suncook River upstream of the collapsed railroad bridge. While currently a functioning wetland, incision of an additional 6-10 ft, which could occur if the Suncook River continues to incise, could cause loss of wetland function and habitat in this area. 2013 Inter-Fluve, Inc. Suncook River, Epsom, NH 3 Not stabilizing the river channel may also result in the continued excessive erosion and release of sediments into the tributaries and mainstem Suncook River. About a month after the avulsion occurred, research showed extremely high Total Suspended Solids (TSS) levels of nearly 280 mg/L in some locations (Daley, 2006). Estimates of the volume of material that eroded downstream as a result of the avulsion range from 118,000 cubic yards (Perignon, 2007) to a NHGS estimate of 150,000 cubic yards (Wittkop et al., 2007 in Perignon, 2007). This material was deposited in the Suncook River channel and along the floodplains. While channel migration and movement of sediment within channels and floodplains is a natural and necessary process to the form and function of rivers and floodplains as well as the robustness of in-channel and riparian habitat, excessive amounts of sediment mobilization and deposition as a result of catastrophic changes may have significant impacts on aquatic organism survival. Completing no channel or bank stabilization along the Suncook River may continue the excessive erosion occurring along the Suncook River until the knickpoints dissipate miles upstream. The volume of sediment added to the river system
Load more

Recommended publications
  • Geomorphic Classification of Rivers
    9.36 Geomorphic Classification of Rivers JM Buffington, U.S. Forest Service, Boise, ID, USA DR Montgomery, University of Washington, Seattle, WA, USA Published by Elsevier Inc. 9.36.1 Introduction 730 9.36.2 Purpose of Classification 730 9.36.3 Types of Channel Classification 731 9.36.3.1 Stream Order 731 9.36.3.2 Process Domains 732 9.36.3.3 Channel Pattern 732 9.36.3.4 Channel–Floodplain Interactions 735 9.36.3.5 Bed Material and Mobility 737 9.36.3.6 Channel Units 739 9.36.3.7 Hierarchical Classifications 739 9.36.3.8 Statistical Classifications 745 9.36.4 Use and Compatibility of Channel Classifications 745 9.36.5 The Rise and Fall of Classifications: Why Are Some Channel Classifications More Used Than Others? 747 9.36.6 Future Needs and Directions 753 9.36.6.1 Standardization and Sample Size 753 9.36.6.2 Remote Sensing 754 9.36.7 Conclusion 755 Acknowledgements 756 References 756 Appendix 762 9.36.1 Introduction 9.36.2 Purpose of Classification Over the last several decades, environmental legislation and a A basic tenet in geomorphology is that ‘form implies process.’As growing awareness of historical human disturbance to rivers such, numerous geomorphic classifications have been de- worldwide (Schumm, 1977; Collins et al., 2003; Surian and veloped for landscapes (Davis, 1899), hillslopes (Varnes, 1958), Rinaldi, 2003; Nilsson et al., 2005; Chin, 2006; Walter and and rivers (Section 9.36.3). The form–process paradigm is a Merritts, 2008) have fostered unprecedented collaboration potentially powerful tool for conducting quantitative geo- among scientists, land managers, and stakeholders to better morphic investigations.
    [Show full text]
  • Seasonal Flooding Affects Habitat and Landscape Dynamics of a Gravel
    Seasonal flooding affects habitat and landscape dynamics of a gravel-bed river floodplain Katelyn P. Driscoll1,2,5 and F. Richard Hauer1,3,4,6 1Systems Ecology Graduate Program, University of Montana, Missoula, Montana 59812 USA 2Rocky Mountain Research Station, Albuquerque, New Mexico 87102 USA 3Flathead Lake Biological Station, University of Montana, Polson, Montana 59806 USA 4Montana Institute on Ecosystems, University of Montana, Missoula, Montana 59812 USA Abstract: Floodplains are comprised of aquatic and terrestrial habitats that are reshaped frequently by hydrologic processes that operate at multiple spatial and temporal scales. It is well established that hydrologic and geomorphic dynamics are the primary drivers of habitat change in river floodplains over extended time periods. However, the effect of fluctuating discharge on floodplain habitat structure during seasonal flooding is less well understood. We collected ultra-high resolution digital multispectral imagery of a gravel-bed river floodplain in western Montana on 6 dates during a typical seasonal flood pulse and used it to quantify changes in habitat abundance and diversity as- sociated with annual flooding. We observed significant changes in areal abundance of many habitat types, such as riffles, runs, shallow shorelines, and overbank flow. However, the relative abundance of some habitats, such as back- waters, springbrooks, pools, and ponds, changed very little. We also examined habitat transition patterns through- out the flood pulse. Few habitat transitions occurred in the main channel, which was dominated by riffle and run habitat. In contrast, in the near-channel, scoured habitats of the floodplain were dominated by cobble bars at low flows but transitioned to isolated flood channels at moderate discharge.
    [Show full text]
  • Official List of Public Waters
    Official List of Public Waters New Hampshire Department of Environmental Services Water Division Dam Bureau 29 Hazen Drive PO Box 95 Concord, NH 03302-0095 (603) 271-3406 https://www.des.nh.gov NH Official List of Public Waters Revision Date October 9, 2020 Robert R. Scott, Commissioner Thomas E. O’Donovan, Division Director OFFICIAL LIST OF PUBLIC WATERS Published Pursuant to RSA 271:20 II (effective June 26, 1990) IMPORTANT NOTE: Do not use this list for determining water bodies that are subject to the Comprehensive Shoreland Protection Act (CSPA). The CSPA list is available on the NHDES website. Public waters in New Hampshire are prescribed by common law as great ponds (natural waterbodies of 10 acres or more in size), public rivers and streams, and tidal waters. These common law public waters are held by the State in trust for the people of New Hampshire. The State holds the land underlying great ponds and tidal waters (including tidal rivers) in trust for the people of New Hampshire. Generally, but with some exceptions, private property owners hold title to the land underlying freshwater rivers and streams, and the State has an easement over this land for public purposes. Several New Hampshire statutes further define public waters as including artificial impoundments 10 acres or more in size, solely for the purpose of applying specific statutes. Most artificial impoundments were created by the construction of a dam, but some were created by actions such as dredging or as a result of urbanization (usually due to the effect of road crossings obstructing flow and increased runoff from the surrounding area).
    [Show full text]
  • Flood Study of the Suncook River in Epsom, Pembroke, and Allenstown, New Hampshire, 2009
    Prepared in cooperation with the Federal Emergency Management Agency Flood Study of the Suncook River in Epsom, Pembroke, and Allenstown, New Hampshire, 2009 Scientific Investigations Report 2010–5127 U.S. Department of the Interior U.S. Geological Survey Cover. Photograph looking downstream at area of Suncook River avulsion, Epsom, New Hampshire. (Photograph taken on June 18, 2008) Flood Study of the Suncook River in Epsom, Pembroke, and Allenstown, New Hampshire, 2009 By Robert H. Flynn Prepared in cooperation with the Federal Emergency Management Agency Scientific Investigations Report 2010–5127 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior KEN SALAZAR, Secretary U.S. Geological Survey Marcia K. McNutt, Director U.S. Geological Survey, Reston, Virginia: 2010 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment, visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprod To order this and other USGS information products, visit http://store.usgs.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted materials contained within this report. Suggested citation: Flynn, R.H., 2010, Flood study of the Suncook River in Epsom, Pembroke, and Allenstown, New Hampshire, 2009: U.S.
    [Show full text]
  • Variable Hydrologic and Geomorphic Responses to Intentional Levee Breaches Along the Lower Cosumnes River, California
    Received: 21 April 2016 Revised: 29 March 2017 Accepted: 30 March 2017 DOI: 10.1002/rra.3159 RESEARCH ARTICLE Not all breaks are equal: Variable hydrologic and geomorphic responses to intentional levee breaches along the lower Cosumnes River, California A. L. Nichols1 | J. H. Viers1,2 1 Center for Watershed Sciences, University of California, Davis, California, USA Abstract 2 School of Engineering, University of The transport of water and sediment from rivers to adjacent floodplains helps generate complex California, Merced, California, USA floodplain, wetland, and riparian ecosystems. However, riverside levees restrict lateral connectiv- Correspondence ity of water and sediment during flood pulses, making the re‐introduction of floodplain hydrogeo- A. L. Nichols, Center for Watershed Sciences, morphic processes through intentional levee breaching and removal an emerging floodplain University of California, Davis, California, USA. restoration practice. Repeated topographic observations from levee breach sites along the lower Email: [email protected] Cosumnes River (USA) indicated that breach architecture influences floodplain and channel hydrogeomorphic processes. Where narrow breaches (<75 m) open onto graded floodplains, Funding information California Department of Fish and Wildlife archetypal crevasse splays developed along a single dominant flowpath, with floodplain erosion (CDFW) Ecosystem Restoration Program in near‐bank areas and lobate splay deposition in distal floodplain regions. Narrow breaches (ERP), Grant/Award Number: E1120001; The opening into excavated floodplain channels promoted both transverse advection and turbulent Nature Concervancy (TNC); Consumnes River Preserve diffusion of sediment into the floodplain channel, facilitating near‐bank deposition and potential breach closure. Wide breaches (>250 m) enabled multiple modes of water and sediment transport onto graded floodplains.
    [Show full text]
  • A History of Chichester
    A History of Chichester . Written on the occasion of our 250th Anniversary 1727 -1977 CONTENTS Preface. .. 5 The Establishment of Chichester. .. 7 Original Gran t . .. 8 Early Beginnings. .. 10 The Settlement of Chichester. .. 22 The Churches. .. 58 The Schools. .. 67 Old Home Day Celebrations. .. 80 Organizations. .. 87 Town Services. 102 Town Cemeteries. 115 Wars and Veterans. .. 118 3 PREFACE Our committee was formed to put into print some account of our town's history to commemorate the 250th anniversary of the granting of the original charter of our town. The committee has met over the past year and one-half and a large part of the data was obtained from the abstracts of the town records which were kept by Augustus Leavitt, Harry S. Kelley's history notes written in 1927 for the 200th anniversary and from the only sizable printed history of Chichester written by D. T. Brown in Hurd's History of Merrimack and Belknap Counties containing thirty seven pages. In researching we found that a whole generation is missing. It is regrettable that a history wasn't done before now when much that is now lost was within the mem- ory of some living who had the knowledge of our early history. Our thanks to the townspeople who have contributed either information, pic- tures, maps and written reports. It is our hope that the contents will be interesting and helpful to this and future generations. The Chichester History Committee Rev. H. Franklin Parker June E. Hatch Ruth E. Hammen 5 THE ESTABLISHMENT OF CHICHESTER Chichester was one of seven towns granted in New Hampshire in 1727 while Lieutenant Governor John Wentworth administered the affairs of the province, then a part of Massachusetts.
    [Show full text]
  • Finley Creek Alluvial Fan Geomorphic and Hydraulic Analyses and Implications for Restoration
    FINLEY CREEK ALLUVIAL FAN GEOMORPHIC AND HYDRAULIC ANALYSES AND IMPLICATIONS FOR RESTORATION Jeanne E. Godaire, Geomorphologist, Bureau of Reclamation, Denver, Colorado, [email protected]; Sean Kimbrel, Hydraulic Engineer, Bureau of Reclamation, Denver, Colorado, [email protected] INTRODUCTION Finley Creek, located on the Olympic Peninsula in western Washington, is a tributary of the Quinault River upstream of Lake Quinault. Previous observers have noted recent progressive lateral movement of the channel toward the eastern side of the Finley Creek alluvial fan, and aggradation and perching of the channel in the vicinity of the North Shore Road Bridge. The relationship between Finley Creek and the Quinault River is one of a long-term dynamic interaction between a large alluvial fan and mainstem river. The current sediment production from Finley Creek is of critical concern due to ongoing dredging at North Shore Road Bridge and the potential environmental effects of the dredging both upstream and downstream of the bridge (NPS, 2005) and sediment deposition and lateral Quinault River channel migration (GeoEngineers, 2011). Previous studies on Finley Creek have documented historical channel change using rectified aerial photography (Bountry et al. 2005) and the problems associated with aggradation and erosion on sections of Finley Creek (Kennard, 2009; Smillie, 2001; Jackson and Smillie, 1994). The objectives of this study are to (1) provide a geomorphic analysis of conditions on Finley Creek in order to place current conditions into a long term context and to identify areas of potential avulsion and lateral erosion; and (2) conduct hydraulic modeling of various scenarios to guide the evaluation of alternatives for addressing aggradation near the North Shore Road Bridge and improvement of aquatic habitat on Finley Creek.
    [Show full text]
  • Surface Water Supply of the United States 1960
    Surface Water Supply of the United States 1960 Part 1 -A. North Atlantic Slope Basins, Maine to Connecticut Prepared under the direction of E. L. HENDRICKS, Chief, Surface Water Branch GEOLOGICAL SURVEY WATER-SUPPLY PAPER 1701 Prepared in cooperation with the States of Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont, and with other agencies UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1961 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. PREFACE This report was prepared by the Geological Survey in coopera­ tion with the States of Connecticut, Maine, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont, and with other agencies, by personnel of the Water Resources Division, L. B. Leopold, chief, under the general direction of E. L. Hendricks, chief, Surface Water Branch, and F. J. Flynn, chief, Basic Records Section. The data were collected and computed under supervision of dis­ trict engineers, Surface Water Branch, as follows: D. F. Dougherty............................................................. Albany, N. Y. G. S. Hayes................................................................. Augusta, Maine John Horton................................................................. Hartford, Conn. C. E. Knox................................................................... Boston, Mass, HI CALENDAR FOR WATER YEAR 1960
    [Show full text]
  • FRIPP INLET, SOUTH CAROLINA Timothy W. Kana P
    SCALES & SIGNATURES OF EPISODIC SAND BYPASSING AT A TIDE-DOMINATED INLET — FRIPP INLET, SOUTH CAROLINA Timothy W. Kana PhD, PG1, Steven B Traynum MS1, and Haiqing Liu Kaczkowski PhD, PE1 This paper provides a case example of meso-scale sand circulation and volumes in a tide-dominated inlet (Fripp Inlet, South Carolina, USA) and the adjacent barrier island. Episodic bypassing is the dominant process controlling shoreline change in this area (Gaudiano & Kana 2001). The scale of bypassing in this case has proven to be more than adequate to restore a highly eroding armored beach along Fripp Island. Upward of 2.7 million cubic meters (m³) shifted from the ebb-tidal delta of Fripp Inlet to a central oceanfront area of Fripp Island between 1989 and 2012. This volume, representing roughly 10 percent of the ebb-tidal delta volume, provided natural nourishment equivalent to nearly 600 cubic meters per meter of shoreline (m³/m) along the nearly 5-kilometer (km) long barrier island. The volume density varied greatly with some beach segments widening by more than 500 m. Prior to the bypassing events, there was no beach at high tide along most of the island. The paper discusses the possible trigger for recent bypassing events and documents changes in Fripp Inlet. Channel rotation into a seawall, southerly deflection of the ebb-delta centroid, and large inputs of sand from the adjacent barrier island appear to have produced conditions promoting large releases of sand to Fripp Island. While the influx of sand has restored much of the oceanfront, full restoration of a sandy beach along the inlet margin will require a channel avulsion or realignment such that the principal erosion-causing process—ebb jet in the main channel—no longer encroaches on the seawall.
    [Show full text]
  • Fluvial Systems – Meandering Rivers Rio Solimoes, Brazil Synthetic Aperture Radar Characteristics of Meandering Rivers
    Fluvial systems – meandering rivers Rio Solimoes, Brazil synthetic aperture radar Characteristics of meandering rivers generally confined within one major channel secondary channels active during floods wide valley, channel is a small part of entire valley Characteristics of meandering rivers Compared with braided river: •low gradient • greater sinuosity • greater % suspended load (less bedload) • finer-grained sediments • more constant discharge (usually perennial flow) Meanders, San Joaquin River cohesive banks, little coarse sediment Meanders, Sacramento River (transitional) less cohesive banks, moderate coarse sediment Amazon River meanders an extreme in bank stability (short-term) Scroll plain Rio Apure, Orinoco Basin Meanders and scroll plains Cross section of river valley & channel River valley Active river channel A natural river valley Landforms Note: levees along outside of meanders Meandering and sinuosity Path of highest-velocity flow Point bars lateral accretion of point bars along inside of meander Cut bank and point bar Cut bank, Fountain Creek, New Mexico Point bar, upstream Fountain Creek, New Mexico Point bar, downstream Fountain Creek, New Mexico Flood channel Enhanced turbulence at confluence text Features of a meandering river Figure 5.12a Figure 5.12b Figure 5.12b Figure 5.12c Figure 5.12c Meander cut-off Forming an oxbow lake Overbank deposition Bankfull discharge flood water level up to the top of the channel maintains the primary channel occurs once every 1-2 years Bankfull discharge Bankfull Average flow Figure
    [Show full text]
  • Developing Impervious Surface Estimates for Coastal New Hampshire
    University of New Hampshire University of New Hampshire Scholars' Repository Institute for the Study of Earth, Oceans, and PREP Reports & Publications Space (EOS) 12-2002 Developing Impervious Surface Estimates for Coastal New Hampshire David G. Justice [email protected] Fay A. Rubin [email protected] Follow this and additional works at: https://scholars.unh.edu/prep Part of the Marine Biology Commons Recommended Citation Justice, David G. and Rubin, Fay A., "Developing Impervious Surface Estimates for Coastal New Hampshire" (2002). PREP Reports & Publications. 298. https://scholars.unh.edu/prep/298 This Report is brought to you for free and open access by the Institute for the Study of Earth, Oceans, and Space (EOS) at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in PREP Reports & Publications by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. DEVELOPING IMPERVIOUS SURFACE ESTIMATES FOR COASTAL NEW HAMPSHIRE A Final Report to The New Hampshire Estuaries Project Submitted by David Justice and Fay Rubin Complex Systems Research Center Institute for the Study of Earth, Oceans and Space Morse Hall University of New Hampshire, Durham, NH 03824 December, 2002 Revised January, 2003 This report was funded in part by a grant from the Office of State Planning, New Hampshire Estuaries Project, as authorized by the U.S. Environmental Protection Agency pursuant to Section 320 of the Clean Water Act. Table of Contents Executive Summary …………………………………………………………………………….…. 2 List of Tables………………………………………………………………………………………. 3 List of Figures……………………………………………………………………………………… 3 Introduction………………………………………………………………………………………… 4 Project Goals and Objectives………………………………………………………...…………….
    [Show full text]
  • Lake Level Management a Balancing Act Nh Lakes
    LAKE LEVEL MANAGEMENT A BALANCING ACT NH LAKES June 16, 2021 James W. Gallagher, Jr., P.E Chief Engineer Dam Bureau 271-1961 [email protected] State Dams Hazard Classification AGENCY TOTALS HIGH SIG. LOW NM DES 40 25 40 6 111 NHFG 4 6 43 47 100 DNCR 2 3 9 17 31 DOT 1 4 4 18 27 UNH 1 1 0 3 5 Glencliff 0 0 0 2 2 Veterans Home 0 0 0 2 2 TOTAL 48 39 96 95 278 Recreational Resources Ossipee Lake Squam Lake Newfound Lake Lake Winnipesaukee Winnisquam Lake Lake Sunapeee Emergency Action Plans Inundation Mapping Population At Risk Downstream of State Owned High and Significant Hazard Dams More than 4,000 houses More than 130 State Road Crossings More than 800 Town Road Crossings Dam Operations Emergency Operations Remote Dam Operations DEPTH (in feet) LAKE RIVER TOWN START DATE FROM FULL Angle Pond Bartlett Brook Sandown Oct. 13 2’ Akers Pond Greenough Brook Errol Oct. 13 1’ Ayers Lake Tributary to Isinglass River Barrington Oct. 20 3’ Ballard Pond Taylor Brook Derry Oct. 13 2’ Barnstead Parade Suncook River Barnstead Oct. 13 1.5’ Bow Lake Isinglass River Strafford Oct. 13 4’ Buck Street Suncook River East Pembroke Oct. 13 6’ Bunker Pond Lamprey River Epping Oct. 13 2’ Burns Lake Tributary to Johns River Whitefield Oct. 13 1.5’ Chesham Pond Minnewawa Brook Harrisville Oct. 13 2’ Crystal Lake Crystal Lake Brook Enfield Oct. 13 4’ Crystal Lake Suncook River Gilmanton Oct. 13 3’ Deering Reservoir1 Piscataquog River Deering Oct.
    [Show full text]