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Ecological Systems Maintaining and Enhancing Natural Features and Minimizing Adverse Impacts of Infrastructure Projects Module 5 Integrating Infrastructure. Emily Mitchell Ayers, Ph.D. The Low Impact Development Center, Inc. emayers@lowimpactdevelopment.org. Learning Outcomes.
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Ecological SystemsMaintaining and Enhancing Natural Features and Minimizing Adverse Impacts of Infrastructure ProjectsModule 5Integrating Infrastructure
Emily Mitchell Ayers, Ph.D. The Low Impact Development Center, Inc. emayers@lowimpactdevelopment.org
Learning Outcomes • Know how to apply the concept of an energy signature • Be able to predict infrastructure impacts • Be able to minimize infrastructure impacts
Ecologically-Sensitive Design Process • Know where you are • Avoid sensitive areas • Minimize infrastructure impacts • Mitigate unavoidable losses • Improve ecological function where possible
Integrating Infrastructure • Avoiding ecological damage requires integrating infrastructure into the ecosystem in which it is located • Infrastructure is not something that sits on top of an ecosystem; it becomes a part of it • Becoming part of an ecosystem without fundamentally changing it requires understanding the energy signature
The “Energy Signature” • The set of energy sources (called forcing functions) affecting an ecosystem • Ecosystems self-organize in response to their unique energy signatures
Forcing Functions • Sunlight level • Temperature • Precipitation • Hydrologic regime • Fire regime • Inputs • Organic matter • Nitrogen • Phosphorus
Example – Trout Stream • Energy signature • Cold water temperature • Low nutrient inputs • Steady stream base flow • Stream flow large enough to create habitat structures, but not so high as to destroy them • Altering any of these forcing functions will cause changes to this ecosystem
Example – Trout Stream (cont’d) • Once we understand the energy signature of the system, we can see where it will be most important to focus our energy on avoiding impacts • For development in the watershed of a trout stream, the primary focus should be on stormwater management
Example – Trout Stream (cont’d) Suggested integration strategy: • Infiltrate stormwater runoff • Avoids hydromodification • Provides base flow • Avoids thermal impacts • Minimizes nutrient pollution • Avoid building dams and in-stream blockages
Example – Tidal Estuary Salt Marsh • Energy signature: • Tidal flooding • High salinity • Sunlight • Sediment deposition from upstream sources • High nutrient flows from upstream and tidal sources • In this system, infrastructure impacts are most likely to be on sediment and nutrient flows
Example – Tidal Estuary Salt Marsh Suggested integration strategy: • Maintain connectivity between river flows and salt marsh • Avoid building dams • Avoid creating deep channels that shunt sediment out to deep water
Example - Forest • Energy signature: • Time • Gradual self-organization of a complex ecosystem with specialized niches and robust nutrient cycling • Space • Species migration, dispersal, home ranges • Vertically-stratified sunlight regime • High sunlight in canopy • Low sunlight at ground level • Precipitation • Temperature • Most infrastructure impacts relate to time and space
Example – Forest (cont’d) Suggested integration strategy: • Minimize physical disturbance • Reduce infrastructure footprint • Maintain canopy where possible • Maintain connectivity
Key Considerations for Infrastructure • Maintain pre-development hydrology • Maintain pre-development nutrient inputs • Minimize pollution • Maintain pre-development plant cover • Avoid introduction of exotic invasive species
Maintain Pre-development Hydrology • Minimize impervious cover • Minimize soil compaction • Use Low Impact Development techniques
Low Impact Development Use small-scale, distributed Best Management Practices (BMPs) to capture and treat stormwater close to the source Emily Ayers
Best Management Practice Best Management Practices (BMPs) are technologies and methods used to reduce the movement of sediment, pollutants, and runoff to receiving waters LIDC
Maintain Pre-development Nutrient Inputs • Minimize fertilizer use • Treat stormwater and wastewater flows prior to discharge
Minimize Pollution • Minimize pesticide and herbicide use • Prevent illicit and accidental discharges • Use environmentally friendly materials and chemicals
NW2.2 Reduce Pesticides and Fertilizer Impacts • 1 point: manage application rates and control runoff • 2 points: select less toxic fertilizers and pesticides; select plants with lower requirements; increase use of compost • 5 points: select less toxic alternatives AND reduce use • 9 points: no pesticide, herbicide or fertilizer use
NW2.2 Reduce Pesticides and Fertilizer Impacts Need for pesticides and fertilizers can be reduced by: • Plant native species adapted to site conditions • Increase biodiversity • Plant species that will attract beneficial insects • Plant a variety of species; AVOID MONOCULTURES! • Improve soil fertility • Amend soils with compost • Cover bare soils with mulches • Avoid unnecessary compaction by machinery or foot traffic
Maintain Pre-development Plant Cover • Minimize disturbed area • Don’t install turf! • Landscape using native species that are endemic to the site
NW3.2 Control Invasive Species • 5 points: use only locally appropriate and non-invasive plant species • 9 points: identify existing invasive species onsite, and manage for control • 11 points: eliminate existing invasive species from site
NW3.2 Control Invasive Species (cont’d) • Check proposed plantings against a list of locally invasive species • Identify and map all invasive species found onsite and within 2/3 mile of the site • Create a plan to manage and, if possible, eradicate onsite invasive species
CR2.5 Manage Heat Island Effects • 1 point: at least 10% of hardscape surfaces have a surface reflectance index (SRI) of 29 or higher, or are shaded • 2 points: at least 30% of hardscape surfaces have an SRI of 29 or higher, or are shaded • 4 points: at least 60% of hardscape surfaces have an SRI of 29 or higher, or are shaded • 6 points: at least 90% of hardscape surfaces have an SRI of 29 or higher, or are shaded
CR2.5 Manage Heat Island Effects (cont’d) • Increasing vegetation, especially shade-producing trees, significantly reduces the heat island effect • Maximize planting of shade trees adjacent to vegetation. For credit, planting must provide shade within 5 years.
Design Examples • Chesapeake Bay Foundation Headquarters • Maryland Intercounty Connector • Penobscot River Hydropower
Chesapeake Bay Foundation • Philip Merrill Environmental Center • Annapolis, Maryland • Building is LEED™ Platinum rated
Building Features • Geothermal heat • Passive solar design • Rainwater harvesting • Recycled materials • Non-toxic finishes • Solar power Emily Ayers
Site Design • Minimal gravel driveway and parking • Bioretention cell at center of parking area • Building is surrounded by forest, meadow, and wetland habitat Emily Ayers
Maryland Intercounty Connector (ICC) • New highway constructed in suburban Maryland • $370 million environmental program MD SHA
ICC Environmental Programs • Wetland creation • Stream restoration • Stormwater management • Reforestation • Fish passage improvements FWS
Special Design Features • Comprehensive avoidance, minimization and mitigation approach to protect local ecosystems • Extended bridges over parks and waterways to permit wildlife crossing MD SHA
Penobscot River Hydropower • Largest watershed in Maine • Relicensing prompted collaborative effort • Balances fisheries restoration with improved hydropower production • http://www.penobscotriver.org Penobscot River Restoration Trust
Penobscot River Hydropower • Removal of two dams • Construction of fish bypass around a third dam • Improved fish passage at four dams • Improved hydropower generation at six dams Penobscot River Restoration Trust
Ecological Benefits • Unobstructed access to 100% of historic habitat for Sturgeon and striped bass • Improves access to 1,000 miles of upper river habitat for endangered Atlantic salmon • Project is expected to fuel a rebound of the Penobscot ecosystem NPS
Design Exercise Imagine that you were asked to help design a new office park. What approaches would you use to minimize the ecological impact of the project?
Ecologically-Sensitive Design Process • Know where you are • Avoid sensitive areas • Minimize infrastructure impacts • Mitigate unavoidable losses • Improve ecological function where possible
Designing an Office Park • Map out key ecological features of site or set of candidate sites • Select the site with the lowest potential ecological impacts • On selected site, focus development away from important habitat areas
Designing an Office Park • Minimize developed footprint • Design buildings and parking areas to meet but not exceed projected needs • Build up rather than out wherever possible • Minimize use of turf in landscaping • Use native plants rather than exotics for landscaping
Designing an Office Park • Design stormwater infrastructure to mimic predevelopment hydrology • Provide wildlife crossings • Incorporate habitat enhancements into landscaping and undeveloped portions of the site
Review • Avoiding ecological damage requires integrating infrastructure into the ecosystem in which it is located • Projects must work with an ecosystem’s energy signature • Projects should attempt to maintain pre-development conditions and functions to the maximum extent possible
Recommended Resources • FHWA. Eco-Logical: An Ecosystem Approach to Developing Infrastructure Projects. http://www.environment.fhwa.dot.gov/ecological/eco_index.asp • Center for Neighborhood Technology, 2010. The Value of Green Infrastructure: A Guide to Recognizing Its Economic, Environmental and Social Benefits. www.cnt.org • Hydropower Reform Coalition. http://www.dameffects.org/ • Mark Benedict and Edward T. McMahon, 2006. Green Infrastructure, Linking Landscapes and Communities. Island Press, Washington, D.C.