A Watershed Analysis of Long Pond South
Implications for Water Quality and Land-Use Management
Part II

GIS and Erosion Models
Jessica Harold

Layers and Maps
Erosion Potential Model
Erosion
Displacement of soil and organic matter
Causes
Soil type, slope, and land-use
Effects
Algal blooms, harmful to organisms

Creating the Erosion Potential Model
Use soil type, slope, and land-use
Rate each on a scale of 1 to 9 or 0-9
Weighted overlay
Weighted average
Soil type – 40%
Slope – 30%
Land-use – 30%

Erosion Potential Model
Erosion Impact Model
The impact of erosion depends on its proximity to the lake and tributaries
A new layer was created for proximity to the lake and proximity to tributaries
Layer was rated from 1 to 9
Weighted overlay
Erosion potential – 50%, Proximity – 50%

Erosion Impact Model
Roads and Water Quality
Anna Birnberg

 Roads and Lake
Water Quality
Roads have the potential to contribute to water quality degradation
Development leads to increased roads
Role of maintenance

Proper Drainage: Essential in Preventing Pollution

Examples of Culverts

The Road Survey
Paved versus non-paved roads
ÒProblem spotsÓ
House count

Results of the Road Survey
52 roads in LPS watershed
 2 state roads
 8 town
 42 camp roads
90.3 acres of road area
 9.1 acres state
 42.7 acres town
 38.4 acres camp roads
 Camp roads make up
over 40%

Results of the Road Survey
Camp Roads:
16.7% Good (7 roads)
35.7% Acceptable (15)
16.7% Fair (7)
31.0% Poor (13)

Results of the Road Survey
Road Survey: Conclusions
LPN has more ÒgoodÓ roads; LPS has more poor quality roads
Poor condition of ditches and culverts
Over 40% of road area is camp roads, and nearly 50% of camp roads are in fair or poor condition

Septic and Buffer Survey
Rosalind Becker

Septic Systems
Contribution to phosphorus loading
Leaching effluent
Shoreline concerns
System age concerns
1974 Regulations
Site evaluations
Installation restrictions

Septic Survey Questions
How many septic systems are in the watershed?
What is the relative age of septic systems in the watershed?
Where do we expect future development?

Septic Survey Methods
House counts
Shoreline survey
Road survey
Interviews with town officials
Review of town documents

Septic Survey Results
365 houses
126 along shoreline
239 non-shoreline
Replacement of systems
Restricted development
Areas of potential development

Septic Suitability Model
Importance of soils and slope
USGS Criteria
Permeability
Mean depth to bedrock
Erodibility
Nutrient absorption capacity

Septic Suitability Model
Buffer Survey
Importance of buffers
Protect soils from erosion
Remove nutrients, trap sediments
Evaluation parameters
Percent vegetated buffer
Buffer depth
Slope rating

Buffer Survey
Most lots had an acceptable score
No lots with a perfect score
Other observations

North Basin vs. South Basin
Buffer Quality
Septic System and Buffer Conclusions
Replacement of grandfathered systems
Areas of likely development
Range of septic suitability
Acceptable buffer conditions

Future Projections
Eva Gougian

Long Pond South Watershed: 2010 to 2030
Population Projections
Developable land
Subdivisions
Increase in year-round residences

Development
Projections
Land-Use Projections
Regenerating land
Wetlands
Agricultural land
High-impact development
492 acres of mixed forest converted to residential land

Phosphorus Budget Projections
Recommendations and Conclusions
Kristyn Loving

Recommendations
Water quality
Recreation
Roads
Buffer Strips
Septic Systems
Development

Conclusions
Long Pond South is in good shape
Educating the public is important
Foster close collaboration with neighboring lake associations

Acknowledgements
Roy Bouchard
Maine Department of
Environmental Protection
Russell Cole
Department of Biology, Colby College
Russell Danner
Maine Department of Inland
Fisheries and Wildlife
Dale Finseth
Kennebec County Soil and
Water Conservation District
David Firmage
Department of Biology, Colby College
Gary Fuller
Code Enforcement Officer,
Belgrade Municipal Office
Tracey Greenwood
Department of Biology, Colby College
Manuel Gimond
GIS & Quantitative Analysis Specialist, Colby College
David  Halliwell
Maine Department of
Environmental Protection
Jen Jespersen
FB Environmental
D. Whitney King
Department of Biology, Colby College
Richard Marble
Code Enforcement Officer,
Mount Vernon Municipal Office
William Najpauer
Code Enforcement Officer,
Rome Municipal Office
John Rice
and the staff of Castle Island Camps

Questions?