A Watershed Analysis of Long Pond North, Part II
Colby Environmental Assessment Team
December 7th, 2006

Presentation Outline
Development Patterns K.T. Weber
Water and Phosphorus Budgets Kelly Bakulski
Summary and Recommendations Alex McPherson
Time for Questions

Ground Surveys
Roads
Area and Condition
Buffer Strips
Coverage
Residence Count
Seasonal or Year-round
Shoreline proximity

GIS Modeling
Maps
Bathymetry
Slope
Models
Erosion
Development

Using Layers
Erosion Potential
Erosion Potential Model
Erosion Impact
Erosion Impact Model
Road Survey
Road Concerns
Erosion and Sedimentation
Drainage
Maintenance Tools
Crowning
Ditches
Culverts
Diversions

Road Survey Results
Camp roads
Worse condition
More Fair and Acceptable
Targeted Problems
Culverts: 32%
Ditches: 26%
Crowning, diversions, etc.

Road Maps
Buffer Strip Survey
Buffer functions
Protect soil
Remove nutrients and trap sediment
Maintain natural habitat
Evaluation Parameters

Buffers
Buffer Strip Survey
Overall good buffers
Weaknesses
Depth
Canopy trees
Commercially developed areas

Residence Count
Measure human impact
Wastewater
Recreational use
Shoreline Houses
Within 250 ft

Residences
479 Houses
Year-round
Shoreline
Residential Density
High in developed areas
Lowered by tracts of undeveloped land

Undeveloped Areas
Significant portion of shoreline
Some development options
Protects water quality
Less human impact
Ecosystem buffer

Septic Suitability
GIS Map
Soil type
Porosity
Slope
Many Sites Suitable
Few Areas of Concern
Leveling, import soil

Residential Density
Development Potential
Proximity to lake
Proximity to existing infrastructure
Ease of construction
Slope
Soil type

Future Considerations
Roads
Poor general condition
Easy remedies
Buffers
Good general condition
Maintain depth
Residential Count
Relatively low
Many development opportunities

Water and Phosphorus Budgets
Kelly Bakulski

Water Budget Significance
Flushing Rate

Water Budget Methods
Basic relationship: (assuming no change in water level)
   runoff + direct inflow + precipitation = evaporation + outflow

Physical Parameters
Calculating the Net Input
Inet = (runoff * watershed area) + (precipitation * lake area) – (evaporation * lake area)
Inet = (0.622 * 2.316 x 107) + (1.057 * 5.160 x 106) – (0.560 * 5.160 x 106)
Inet Long Pond North = 1.697 x 107 m3/year

Input From
Other Lakes
Flushing Rate
Flushing Rate = [(Inet Long Pond) + (Inet Input1) + � (Inet Inputn)] / (Volume of Lake)
Flushing Rate = (1.324 x 108)/(3.492 x 107)
Flushing rate of Long Pond North is 3.79 flushes per year.

Phosphorus Budget
Total amount of P entering a lake from specific sources
Why?
Problem sources
Future projections

Phosphorus Budget
Dependent on:
Land Use
Population (Septic Use)
Soil Retention
Point-Source Inputs

Amount of Phosphorus Entering Long Pond North (W)
Land Use (L) and
Lake Concentration (P)
Phosphorus Loading
L = W / As
P = L / (11.6 + 1.2qs)

Results
With Sediment Release
Range: 6.2 - 12.7 ppb
Best Estimate: 8.7 ppb
Sampled Site 1
Mean Epicore: 7.6 ppb

Percent Contribution of Phosphorus
Slide 36
Future Projections of Phosphorus Budget
Flow patterns

Summary and Recommendations
Alex McPherson

Long Pond Value
Aesthetic
Economic
Land values
Ecological
Belgrades
Kennebec

Threats
Phosphorous loading
Gloeotrichia
Invasive species

Phosphorous Loading
Recommendations
Land use
Maintain trends
Undeveloped Lots
Septic systems
Maintenance
Remediation
Camp Roads
Maintenance programs

Gloeotrichia
Blue green algae or cyanobacteria
Seen on the surface
Currently being studied at Colby

Invasive plants
Introduced by boats
�Clog up� the lake
Are found in neighboring lakes

Recommendations
Continue to be vigilant!

Main Message
Long Pond is in good shape
With continued community support, it can stay that way

Acknowledgments
Earl Bacon
Bernadette Bibber
Curtis Bohlen
Roy Bouchard
Amanda Brown
Dale Finseth
David Firmage
Gary Fuller
Danielle Garneau
David Halliwell
Steve Harmon
Jen Jesperson
Dennis Keschl
D. Whitney King
William Najpauer
Kirsten Ness
Tricia Rouleau
Tom and Carmen Tucker

Questions?