comprehensive planning for lake and stream protection brie begiebing water resources specialist...
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Comprehensive Planning for Lake and Stream Protection
Brie Begiebing
Water Resources Specialist
Portland Water District
The Problem . . .
• Some of our lakes are severely stressed by Nonpoint Source Pollution (or polluted stormwater runoff)
• Lakes are especially vulnerable to pollution
Sediments
Phosphorus and other nutrients
Pathogens
Toxic Contaminants
Debris
Non Point Source Pollution Contains:
Excess Algae
Decreased Clarity
Less Oxygen
Thermal Stress
And Causes:
Nonpoint Source (NPS) Pollution is the #1 water quality problem
in the U.S.
In most lake watersheds, about 60%-80% of pollution is from
NPS!
Stormwater
Construction
Logging
Fertilizer
Camp Roads
Septic
PP
P
P
P
P
P - Inflow P - Outflow
P
P
P
P
P
P
P - Inflow
PP
P
P
P
Phosphorus in Lakes
P - Storage
Canadian Experimental Lakes
Area (#226)
•Pristine lake divided into two halves
• P (ppb - parts per billion) added to only one side
• Repeated for 8 yearsSource: ELA, Fisheries and Oceans Canada
10 ppb
1 ppb
Protects the soil from erosion Slows the runoffTraps nutrients, sediments and bacteria
Natural Wetlands
Raindrop Erosion
Pit & Mound Topography
Natural Duff
Lakeside Home with Natural Buffer
Protective Canopy
In an undisturbed watershed natural vegetation:
Unfortunately many human activities not only generate pollution, they disturb this natural filter . . .
Impervious surfaces Impervious surfaces increaseincrease runoff and runoff and decreasedecrease infiltration infiltration
Impervious surfaces include compacted gravel, asphalt, roofing...
Water moves faster on impervious
surfaces.
How Impervious Surfaces How Impervious Surfaces Change the Water BudgetChange the Water Budget
50%50%10%10%5555%% 1515
%%
Natural CoverDeveloped Land
75-100% Impervious Surface
Infiltration
Runoff
40%Evaporation
3030%%
Natural buffers also
regulate light and
temperature and
provide important habitat for
wildlife
NPS Pollution directly effects streams and the organisms that live there
Environmental Health EffectsEnvironmental Health Effects
• Reduced wildlife habitat
• Decline in cold water fisheries
• Lower water quality
Decline in Property ValuesDecline in Property Values
• For every 3 ft. decline in water clarity, shorefront property values can decline as much as 10-20%.
• Declining property values affect individual landowners and economics of entire communities.
Lakes Most at Risk from Development
•Sebago Lake
•Watchic Pond
•Little Watchic Pond
•Rich Mill Pond
What the Comprehensive Plan What the Comprehensive Plan can do to protect lakes and can do to protect lakes and
streamsstreams
• Call for ordinances that protect water resources
• Recommend the formation and funding of a conservation commission
• Support lake protection activities by lake and road associations
• Support the education of residents and town officials on water quality protection methods