NORTHWOOD LAKE

A view on the lake

Photo.
Photo: M. Martin  
 

A. LOCATION

New Hampshire, USA.
43:3N, 71:5W; 158 m above sea level.

B. DESCRIPTION

Northwood Lake is a long, narrow, shallow lake located in southeastern New Hampshire, in the town of Northwood, Rockingham County. It is situated approximately 18 miles from Concord, and has 2 miles of shoreline along Route 4, the major east-west highway between the capital city area and the state university, the seashore, and the state of Maine. It is a natural lake raised by damming, having an area of 278 hectares, a mean depth of 2.8 meters, and a maximum depth of 7.3 meters.
The lake functions as the final settling basin for several lakes in its 6,226 hectares watershed, prior to its discharge forming the Little Suncook River. The watershed is primarily rural forested and agricultural lands. A large dairy farm and associated corn fields lie along its major tributary Narrows Brook.
Northwood Lake has a free and unencumbered boat launch, a commercial marine, a town beach that is available to non-residents, and a Boy Scout camp. Most of the lake's shoreline is developed, consisting primarily of single family camps and homes. A restaurant and several businesses are located near the lake along Route 4 and a trailer park exists on the shoreline at Northwood Narrows (Q, 3).

C. PHYSICAL DIMENSIONS (1)

     
    Surface area [km2] 3
    Volume [km3] 0.0097
    Maximum depth [m] 7.6
    Mean depth [m] 3.7
    Water level Regulated
    Normal range of annual water
    level fluctuation [m] 1.5
    Residence time [yr] 0.3
    Catchment area [km2] 41
     
 

D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL (1)
Bathymetric map: Fig. NAM-36-01.
Number of outflowing rivers and channels (name): 1 (Northwood Lake Outlet).
D2 CLIMATIC (1)
Climatic data at Concord, June 1980-May 1981
Mean temp. [deg C]
     
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
    -11 -1 1 8 14 19 21 19 15 7 -2 -7 6.9
     
Precipitation [mm]: Mean Annual precipitation ca. 1,000.
Solar radiation: 32.5 MJ m-2 day-1.
    Possible Sunshine [% yr-1]
    1979 1980 1981 1982
    53 59 58 58
     
(Data from NOAA located in Concord, New Hampshire)
    Fig. NAM-36-01
    Bathymetric map (2).
 

Water temperature [deg C] Station 1*, June 1980-May 1981 [m]

     
    Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0 - - - 11.2 14.2 22.0 26.0 19.8 18.8 13.5 4.0 -
    1 - - - 11.1 14.2 22.0 26.0 19.8 18.8 13.5 4.0 -
    2 - - - 11.1 14.2 20.5 26.0 19.8 18.5 13.4 4.0 -
    3 - - - 11.0 14.2 19.5 25.9 19.8 18.2 13.3 4.0 -
    4 - - - 11.0 14.2 17.5 24.2 19.7 17.9 13.3 4.0 -
    5 - - - 11.0 14.2 17.5 22.2 19.6 17.5 13.2 4.0 -
    6 - - - 10.9 14.2 - - - 17.1 13.2 4.0 -
    6.5 - - - - 14.2 - - - - 13.1 4.0 -
    * Deep Hole.
Freezing period: December-March.
Mixing type: Dimictic.
Notes on water mixing and thermocline formation: No stratification observed.

E. LAKE WATER QUALITY (1)

E1 TRANSPARENCY [m]
Station 1*, June 1980-May 1981 [m]
     
    Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    - 2.0 - 3.0 2.5 3.0 4.8 3.6 2.9 4.3 2.9 2.2
    * Deep Hole.
E2 pH
Station 1, June 1980-May 1981
[m]
     
    Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0-1 6.2 6.4 - 6.2 6.2 6.6 6.6 - 2.9 6.2 6.6 5.8
    2-3 6.0 6.2 - 6.0 6.1 6.6 6.0 4.1 6.3 6.3 6.4 5.8
    4-5 5.9 6.0 - 6.0 6.1 6.4 6.3 6.3 6.2 6.3 6.4 5.7
    B* - - - 6.0 6.1 - - 6.3 6.3 6.4 - -
     
* Bottom.
E3 RESIDUE [mg l-1]
Pleasant Lake Brook, June 1980-May 1981
[m]
     
    Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    21 45 35 31 49 62 67 30 95 2 25 51
     
E4 DO [mg l-1]
Station 1*, June 1980-May 1981
[m]
     
    Depth Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0 - - - 11.0 9.9 8.7 8.2 8.0 8.9 8.9 11.7 -
    1 - - - 10.9 9.8 8.6 8.2 8.1 8.9 8.9 11.7 -
    2 - - - 10.9 9.8 8.7 8.2 8.0 8.9 8.9 11.7 -
    3 - - - 10.9 9.8 8.4 8.2 8.0 8.9 8.9 11.7 -
    4 - - - 10.9 9.8 8.2 7.4 8.0 8.7 8.8 11.7 -
    5 - - - 10.8 9.8 7.6 6.4 7.9 8.4 8.8 11.7 -
    6 - - - 10.6 9.8 - - 7.9 8.2 8.8 11.7 -
    6.5 - - - 9.8 - - - - - - - -
     
* Deep Hole.
E6 CHLOROPHYLL CONCENTRATION [micro g l-1]
Station 1*, June 1980-May 1981
[m]
     
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    1.71 0.28 - 2.33 5.32 5.14 2.54 3.42 3.71 2.82 2.21 1.90
    * Deep Hole.
E7 NITROGEN CONCENTRATION
Total-N [mg l-1]
Station 1*1, June 1980-May 1981
[m]
     
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0-1 .33 .66 - .36 .35 .50 .27 - .33 .43 - .36
    2-3 .37 .48 - .36 .40 .42 .32 .25 .74 .35 - .42
    3-4 .53 .48 - .35 .34 .48 .27 .31 .39 .28 - .40
    B*2 - - - .34 .31 - - .25 .40 .36 - -
    *1 Deep Hole. *2 Bottom.
E8 PHOSPHORUS CONCENTRATION
Total-P [mg l-1]
Station 1*1, June 1980-May 1981
[m]
     
    Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
    0-1 .010 .028 - .016 .015 .024 .014 - .010 .009 .015 .014
    2-3 .009 .020 - .016 .020 .024 .013 .013 .010 .009 .013 .019
    4-5 .022 .032 - .018 .019 .030 .013 .009 .008 .009 .023 .024
    B* - - - .029 .018 - - .004 .009 .011 - -
    *1 Deep Hole. *2 Bottom.
 

F. BIOLOGICAL FEATURES

F1 FLORA (1)
Emerged macrophytes
Cephalanthus occidentalis Sagittaria latifolia, Cyperaceae, Sparganium, Typha, Carex, Eriocaulon septangulare, Dulichium arundinaceum, Pontederia cordata, Eleocharis, Phragmites communis, Scirpus.
Floating macrophytes: Nuphar, Nymphaea, Brasenia schreberi.
Submerged macrophytes
Potamogeton, Vallisneria americana, Myriophyllum humile, Utricularia, Nitella.
Phytoplankton
Asterionella, Tabellaria, Anabaena, Lyngbya, Chrysochromulina breviturrita, Mallomonas, Dinobryon, Synura.
F2 FAUNA
Zooplankton (1)
Rotifers (Kellicottia, Keratella, Polyarthra), Crustaceans (Daphnia), Calanoid copepods, Cyclopoid copepods, Nauplius larvae, Cilliates (Tintinnidium).
Fish (4, 5)
Stocked with Morone americana (white perch), Ictalurus natalis (horned pout), Micropterus dolomieui (small mouth bass), Perca flavescens (yellow perch), Notemigonus chrysoleucas (golden shiner), Astacidae, crayfish, Esox niger (eastern chain pickerell), also present Micropterus salmoides (large mouth bass), minnows, suckers, sunfish.

G. SOCIO-ECONOMIC CONDITIONS

G1 LAND USE IN THE CATCHMENT AREA (1)
1982
     
    Area [km2] [%]
    Natural landscape
    Forested ca.26 63
    Wetland/waterbody ca. 7 16
    Open land <0.5
    Agricultural land ca. 6 14
    Residential area ca. 2 6
    Others
    Commercial area <0.5
    Total 41 100
     
G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE (Q)
Numbers of domestic animals in the catchment area
Cattle <100, horses <25, sheep <10, poultry <10.
G3 POPULATION IN THE CATCHMENT AREA (Q)
1980
     
    Population Major cities
    Population density [km-2] (population)
    Total 2,175 53.0 None
     
 

H. LAKE UTILIZATION

H1 LAKE UTILIZATION (Q)
Sightseeing and tourism (no. of visitors in 1982: approximately 2,200) and recreation (swimming, yachting, sport-fishing).

I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS (Q)

I1 ENHANCED SILTATION
Extent of damage: Not serious.
I2 TOXIC CONTAMINATION
Present status: None.
Environmental quality standards for contamination in the lake
Toxic concentrations and combinations are evaluated in accordance with EPA's published water quality criteria for 64 toxic substances dated November 1980.
I3 EUTROPHICATION
Nuisance caused by eutrophication
Unusual algal bloom (Chrysochromulina breviturrita) with rotten odor of lake.
Nitrogen and phosphorus loadings to the lake [kg P yr-1]
1981
     
    Sources Industrial Domestic Agricultural Natural Total
    T-P - 162.1 244.1 613 1,018.2
     
I4 ACIDIFICATION
Extent of damage: Detected but not serious.

J. WASTEWATER TREATMENTS (1)

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA
    d) Measurable pollution with limited wastewater treatment.
Supplementary notes
In June, 1978, Northwood Lake developed into an extremely offensive rotten- cabbage. Samples of lake water revealed an abundance of a small, bi- flagellated organism, later determined to be Chrysochromulina breviturrita. This was a brand new species of algae, not described in the literature until 1978 (Nicolls, 1978). During the investigations of this algal problem, high phosphorus levels (up to 50 mg l-1) were found in runoff from a nearby dairy farm. Prior to this algal bloom, the Water Supply and Pollution Control Commission (WSPCC) had received no other complaints concerning nuisance plant growths in Northwood Lake. However, the following year a shortlived, isolated, Anabaena (blue-green algae) bloom was observed in the Lynn Grove - Pine Point area. A general biological survey of the lake, conducted during the summer of 1979, revealed a shallow mesotrophic lake, with relatively low levels of phosphorus and algae. It appeared that although the lake was still in good shape subtle changes were occurring in the watershed to cause sporadic algal blooms. Because of the rarity of the Chrysochromulina organism, and because of the many unanswered questions concerning the high runoff phosphorus levels and sporadic algal bloom, the State/EPA Agreement for FY 1980 called for a diagnostic/feasibility study of Northwood Lake, to be conducted by the WSPCC and funded partly by the Clean Lakes Program.
J3 SANITARY FACILITIES AND SEWERAGE
Percentage of municipal population in the catchment area provided with adequate sanitary facilities (on-site treatment systems) or public sewerage: 100 septic systems for lake shore communities (90% adequate).
Municipal wastewater treatment systems: None.

K. IMPROVEMENT WORKS IN THE LAKE

K1 RESTORATION (Q)
Two applications of copper sulfate in 1978 to reduce the bloom of C. breviturrita.

L. DEVELOPMENT PLANS (Q)

Much of the south side is still available for development and will probably be developed within the next few years.

M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS (Q)

M1 NATIONAL AND LOCAL LAWS CONCERNED
Names of the laws
  1. Federal Water Pollution Control Act Main items of control
  2. Algae & other aquatic nuisances
  3. Exotic aquatic weeds
  4. Illegal dumping & other violations
M3 RESEARCH INSTITUTES ENGAGED IN THE LAKE ENVIRONMENT STUDIES
  1. Department of Environmental Services, Water Supply and Pollution Control Commisssion, Biology Bureau

    2. N. SOURCES OF DATA

    (Q) Questionnaire filled by New Hampshire Water Supply and Pollution Control
        Commission, Concord, New Hampshire.
    (1) Towne, R. E. & Estabrook, R. H. (1982)  Northwood Lake Diagnostic/Feasibility
         Study.  New Hampshire Water Supply and PollutionControl Commission, Staff Report No. 131.
    (2) Classification and Priority Listing of N. H. Lakes Rockingham and
        Strafford Counties, Volume 2, Part 6.  New Hampshire Water Supply and
        Pollution Control Commission, Staff Report No. 121. March,1981.
    (3) Towne, R. E. & Estabrook, R. H. (1979)  A Trophic Study of Northwood Lake,
        Northwood, N. H.  New Hampshire Water Supply and Pollution Control
        Commission.
    (4) Newell, A. E. (1970)  Biological Survey of the Lakes and Ponds in
        Cheshire, Hillsborough and Rockingham Counties.  State of New Hampshire
        Fish and Game Department, Survey Report No. 8C.
    (5) Scarola, J. F. (1973)  Freshwater Fishes of New Hampshire.New Hampshire
        Fish and Game Department, Division of Inland and Marine Fisheries.
    N. SOURCES OF DATA

    (Q) Questionnaire filled by New Hampshire Water Supply and Pollution Control
        Commission, Concord, New Hampshire.
    (1) Towne, R. E. & Estabrook, R. H. (1982)  Northwood Lake
        Diagnostic/Feasibility Study.  New Hampshire Water Supply and Pollution
        Control Commission, Staff Report No. 131.
    (2) Classification and Priority Listing of N. H. Lakes, Rockingham and
        Strafford Counties, Volume 2, Part 6.  New Hampshire WaterSupply and
        Pollution Control Commission, Staff Report No. 121. March,1981.
    (3) Towne, R. E. & Estabrook, R. H. (1979)  A Trophic Study of Northwood Lake,
        Northwood, N. H.  New Hampshire Water Supply and Pollution Control
        Commission.
    (4) Newell, A. E. (1970)  Biological Survey of the Lakes and Ponds in
        Cheshire, Hillsborough and Rockingham Counties.  State of New Hampshire
        Fish and Game Department, Survey Report No. 8C.
    (5) Scarola, J. F. (1973)  Freshwater Fishes of New Hampshire.New Hampshire
        Fish and Game Department, Division of Inland and Marine Fisheries.