| Geographic Information Systems and Modeling |
| Outline |
| What are Geographic Information Systems? | |
| Modeling with GIS | |
| Septic Suitability Model | |
| Erosion Potential Model | |
| Geographic Information Systems |
| Visualization of geographic features and the corresponding physical attributes | ||
| Road map | ||
| Land use type | ||
| Soil map | ||
| Contour map | ||
| Modeling of natural processes using Arc GISª Spatial Analyst | ||
| Modeling with GIS |
| Several input maps | |
| Simulate factors that affect water quality | |
| Septic suitability | |
| Erosion potential | |
| Septic Suitability Model |
| What makes land suitable for septic systems? | ||
| Gentle slopes | ||
| Soil containing loam, sand, and gravel | ||
| Input maps: | ||
| Soil | ||
| Slope | ||
| Soil Map |
| Digitized polygons of the 17 soil types in the watershed | |
| Septic suitability description |
| Septic Suitability of Soils |
| Slope Map |
| Ranked for suitability on a 1 to 9 scale: | ||
| Steep slope = 9 | ||
| Gentle slope = 1 | ||
| Range = 0o to 28o | ||
| Created from digital elevation maps | ||
| Weighted Overlay |
| Septic Suitability Results |
| 84% of watershed suitable | ||
| <1% unsuitable | ||
| Uses: | ||
| Guidance for proper system installation | ||
| Focus remediation efforts | ||
| Erosion Potential Model |
| Displays | ||
| Erodibility of land in watershed | ||
| Potential effect erosion has on water quality | ||
| Accounts for proximity to the lakes and streams | ||
| 5 Input maps | ||
| Soil | ||
| Slope | ||
| Land Use Type | ||
| Proximity to lakes | ||
| Proximity to streams | ||
| Slope and Soil Maps |
| Same slope map | |
| The soils were ranked for erodibility on a 1 to 9 scale based on K values |
| 1998 Land Use Map |
| Proximity Maps |
| Lake proximity zones | ||
| 200 ft | ||
| 1,200 ft | ||
| Stream proximity zones | ||
| 200 ft | ||
| Weighted Overlay |
| Erosion Potential Results |
| Northeast corner has high impact | |
| Wetlands are light gray | |
| Useful for focusing remediation and erosion control efforts |
| Summary of GIS Models |
| Septic suitability model | ||
| Functioning septic systems = better water quality | ||
| Guidance for proper septic placement and installation | ||
| Erosion potential model | ||
| Locates areas that contribute high erosion runoff | ||
| Focus remediation and control efforts for maximum increase in water quality | ||
| Buffer Strip and Septic
Surveys: Results and Remediation Elizabeth Turnbull |
| "Shoreline Zoning Regulations" |
| Shoreline Zoning Regulations | |
| Development Survey | |
| Buffer Strip Survey and Remediation - Septic Systems |
|
| - Septic Remediation |
| MaineÕs Residential Shoreline Zoning Regulations |
| MAXIMUM: | ||
| Structure height | ||
| MINIMUM: | ||
| Setback | ||
| Shore frontage | ||
| Area (ft2) | ||
| Total area of impervious surface | ||
| Development Assessment |
| 560 total houses | ||
| 203 shoreline | ||
| 357 non-shoreline | ||
| 142 seasonal | ||
| 418 year-round | ||
| Buffer Strips |
| "Poorly buffered property" |
| Poorly buffered property | |
| little vegetation | |
| artificial beach | |
| lawn mowed to shore | |
| no deep root systems |
| "Results show a large quantity..." |
| Results show a large quantity of poor and failing buffers |
| Slide 25 |
| Buffer Remediation |
| Avoid mowing to the shore | |
| Native species | |
| Duff layer | |
| Riprap | |
| Winding paths | |
| Any buffer is better than nothing | |
| Wastewater Disposal in Threemile Pond |
| Mostly septic systems | ||
| Common problems: | ||
| Too near the shore | ||
| Old | ||
| Grandfathered | ||
| Leaky | ||
| Septic Health |
| Compost- No Disposal | |
| Conserve water- spread out use | |
| Pump regularly | |
| Replace when expanding and winterizing | |
| Avoid dumping bleach or antibacterial substances | |
| Avoid driving on leach field | |
| Native plants | |
| Low phosphate detergents and soaps | |
| New development? | |
| Some Watershed Remediation
Techniques Sarah Goodwin |
| Overview of Selected Watershed Management |
| Sources | |
| Road Survey | |
| Agriculture | |
| Household remediation |
| Phosphorus Budget |
| Determines the sources of phosphorus within the watershed | |
| Starts with estimations and is adapted to findings | |
| Determines the amount of phosphorus that each land type contributes | |
| Influenced by area of each land use type | |
| Phosphorus Inputs |
| Road Survey |
| Importance of road maintenance, camp roads in particular | |
| Assessed all roads in watershed | |
| Crowning and Grading |
| Smooth surface and a crown that rises 1/2 inch for each foot of road width | |
| Remove berms | |
| Grade when appropriate | |
| Ditches |
| Collect and store storm water | |
| Trapezoidal or parabolic | |
| Vegetation |
| Water Diversions |
| Water bars | |
| Road Assessment Results |
| 22 acres of camp roads | |
| 74 acres of municipal or state roads | |
| Camp roads in worst condition | |
| Implications for Threemile Pond |
| Problem Areas |
| Other Forms of Remediation |
| Agriculture | |
| Household impacts |
| Agriculture |
| Potential impacts | |
| Limit excessive use of fertilizers | |
| Contour cultivation | |
| Stubble mulching | |
| Minimizing tillage | |
| Other Remediation Techniques |
| Fertilizer use | |
| Household products | |
| Boat ramp |
| Some Watershed Remediation Techniques |
| Maintain integrity of roads | |
| Practice agriculture techniques that minimize phosphorus entering lakes | |
| Be aware of household impacts | |
| Importance of managing a watershed before looking to in lake remediation techniques |
| Lake Remediation Aubris Pfeiffer |
| Overview of Remediation |
| Remediation of Threemile Pond | |
| Review of nonapplicable remediation techniques | |
| Recommendations | |
| Implementation in Threemile Pond |
| Definition of Lake Remediation |
| Òthe manipulation of a lake ecosystem to effect an in-lake improvement in degraded or undesirable conditionsÓ | |
| ~Dunst, et al. 1974 |
| Challenges for Threemile Pond Remediation |
| Multiple Towns | |
| Non-point Sources | |
| Nature of a lake system | |
| Cost/benefit analysis |
| Application to Threemile Pond |
| Important to consider: | |
| Technique requirements | |
| Costs/benefits | |
| How it specifically applies to Threemile Pond and its demands |
| Common Remediation Techniques |
| Dredging | ||
| Water removal techniques: | ||
| Hypolimnetic Withdrawal | ||
| Dilution | ||
| Drawdown | ||
| Additional techniques |
| Algicides | ||
| Temporary, toxic, expensive | ||
| Aquatic Plant Harvesting | ||
| Not enough phosphorus in biomass | ||
| Physical Liners | ||
| Application is difficult & expensive, lake size | ||
| Potential Techniques for Threemile Pond |
| Wetland Maintenance | |
| Alum Treatment | |
| Hypolimnetic Aeration | |
| Biological control through fish stock manipulation |
| ALUM TREATMENT |
| Chemically inactivates phosphorus | |||
| Learn from previous treatment | |||
| Inadequate application | |||
| Buffering agent | |||
| More advanced technology | |||
| GPS and GIS to map areas of lake for specific application | |||
| "Ideal tool for determining alum..." |
| Ideal tool for determining alum treatment application |
| Hypolimnetic aeration |
| Prevents anoxic/anaerobic conditions by aerating the hypolimnion | |
| Destratification vs. layer technique | |
| Biological Control: Fish Stock Manipulation |
| Decrease planktivorous fish | ||
| Discontinue stocking of alewives | ||
| Increase piscivorous fish | ||
| Continue/Increase stocking of brown trout | ||
| Stock small & large mouth bass | ||
| Implementation in Threemile Pond |
| Alum treatment, hypolimnetic aeration, and fish stock manipulation are promising | |
| Methods worth further consideration and study | |
| Consider implementation for improvement | |
| Emily Arell |
| Future Predictions and | |
| Recommendations for Threemile Pond | |
| Historic Population Trends |
| Future Population Trends |
| Historic and Future Development Trends |
| Agriculture will continue to decline | ||
| Demand for housing and development will continue to rise | ||
| Shoreline property | ||
| Subdividing of existing lots | ||
| Prediction of Land Use Changes by 2040 |
| Cleared land | |
| Transitional forest | |
| Residential | |
| Municipal | |
| Cropland | |
| Pasture | |
| Mature forest | |
| Reverting | |
| Wetlands | |
| Increase | |
| Increase | |
| Increase | |
| Increase | |
| Decrease | |
| Decrease | |
| Decrease | |
| Decrease | |
| Decrease |
| Watershed Management |
| Maintenance of septic systems | |
| Create Buffer strips | |
| Follow shoreline zoning regulations | |
| Maintain integrity of roads | |
| Practice agriculture techniques that minimize phosphorus entering lakes | |
| Be aware of household impacts | |
| In-lake Remediation Techniques |
| External phosphorus loading must be addressed prior to in-lake treatment for successful remediation | |
| Possible Techniques for Threemile Pond: | |
| 1) Biological control through fish stock manipulation | |
| 2) Alum treatment | |
| 3) Hypolimnetic aeration | |
| Threemile Pond Remediation Summary |
| Assess lakes individually | ||
| Small changes can have a BIG effect | ||
| Address as many problems as possible | ||
| Establish a balance | ||
| Social | ||
| Economic | ||
| Environmental | ||
| Water Quality Monitoring |
| Water monitoring throughout summer-Characterization sites: 1, 2, 3 | ||
| Transparency: bi-weekly | ||
| Dissolved Oxygen: bi-weekly | ||
| Phosphorus: test surface and | ||
| epicore monthly | ||
| Community volunteers | ||
| Community Awareness and Education |
| Work closely with the China Region Lakes Alliance and Threemile Pond Association | |
| Distribute fact sheets and brochures | |
| Provide information in town offices and schools | |
| Involve local schools in monitoring Threemile Pond |
| Grants and Funding |
| Maine DEP website | ||
| Non-point source Water Pollution Control Grants | ||
| Non-governmental funding sources | ||
| Watershed Protection Grant | ||
| Maine Natural Resource Protection Act | ||
| General Summary |
| The primary problem in Threemile Pond is cultural eutrophication | ||
| Remediation must consider all sources of phosphorus runoff | ||
| Water quality will improve with: | ||
| Reduction of external phosphorus loading | ||
| Reduction of sediment release of phosphorus | ||
| Threemile Pond |
| Remediation means the preservation of: | ||
| Environmental Health | ||
| Economic Viability | ||
| Cultural History | ||
| Special Acknowledgments |
| Roy Bouchard | |
| Dave Halliwell | |
| Rebecca Manthy | |
| Jenna Richardson | |
| Nate Sylvester | |
| Dan Dubord | |
| Questions |