plan 453 - quiz 2 Flashcards
environmental indicators
- tools used to evaluate the state of the environment and signal environmental changes important to society
- comprehensive and manageable set of indicators are required to reflect societal concerns, information needs and management strategies
purpose of environmental indicators
- assess current conditions of ecosystem
- document trends over time
- anticipate early warning of degradation
- identify cause of ecosystem degradation
- demonstrate links between system components
environmental indicators - developing a monitoring program
- define vision, goals, and objectives
- develop conceptual model
- choose performance criteria and reference sites
- choose monitoring methods and parameters
- estimate costs
- determine level of effort
factors affecting the dispersion of road salt
factors include temperature, precipitation, soil permeability, and vegetation
need for landscape-based approach to stormwater management (SWM)
- a rationale for considering watersheds as the natural and logical boundary for environmental and land use planning
- direction regarding types of environmental studies that are required for development to take place and the range of expertise needed to be involved
- evidence that current urban design and swm approaches are not sustainable over the long term if watershed goals are to be realized, and therefore, that a change in planning and design practices is required
- enhance swm within existing urban areas
- identify the diverse range of disciplines needed to effectively and successfully undertake an integrated planning and design approach
- recognition that new technologies such as the treatment train approach, low impact development (LID) principle and green building certification systems (e.g. LEED) represent the next step in the evolution of SWM practice.
rational for landscape-based approach to SWM and planning
- ensure infrastructure is fully integrated within both the urban fabric of the community and the functional landscape
- principle that development form, servicing and SWM strategies, defined by the biophysical, hydrological and ecological attributes of the environment and landscape in addition to other planning objectives
- SWM facility planning and design can be better integrated into the development planning process, better site design and identification of environmental opportunities and constraints early on in the process can lead to more effective SWM
landscape-based planning and design principles
- stormwater is a resource
- fully integrated within their physical, social, and ecological contexts
- planning of SWM facilities integral component of the overall land use and environmental planning process. begin at the watershed scale to achieve a full range of community and environmental objectives and targets realized with the primary SWM objective and targets
- design process be focused on maximizing the benefits that can be achieved as a product of the implementation of stormwater management facilities
- integration of SWM facilities with other land uses is desirable
- swm facilities situated and configured to ensure that they are integral components of the community and regional open space system, contribute to the quality of urban design of the community
- consider maintenance requirements of facilities
- to enhance facility performance, minimize maintenance requirements, ensure longevity and address public safety
- integration at a range of scales supported by strategies to ensure that long-term functional requirements are achieved
- public education and interpretation
low-impact development
Sustainable planning and engineering approach to manage stormwater close to its source
treatment train approach
A multi step process for managing stormwater using sequential treament methods
sequence:
1. Source Controls: Managing runoff at the source (green roofs, permeable pavements
- Conveyance Control: Managing flow during transport (bioswales)
- End of pipe control: Managing flow at discharge points (SWM ponds)
**uses a combination of lot-level or source (LID), conveyance and/or end-of-pipe practices to meet water quality, water quantity, water balance, and erosion design criteria for the site
water quantity control mechanisms
- rate reduction techniques: techniques to mimic pre-development or natural conditions
- volume reduction techniques: storage and infiltration
- velocity control
- evapotranspiration
**Reduces flooding risks (detention basins)
water quality control mechanisms
- screening and filtration
- infiltration/groundwater recharge
- settling
- biological uptake
- temperature control
- soil adsorption
**Reduces pollutants in runoff (filtration systems)
source, conveyance, and end of pipe controls
- Source Controls: Managing runoff at the source (green roofs, permeable pavements
- Conveyance Control: Managing flow during transport (bioswales)
- End of pipe control: Managinf fkow at discharge points (SWM ponds)
rainwater harvesting
capturing and storing rainwater for reuse to reduce runoff and conserve water
landscape and drainage considerations for BMP selection
- watershed context (contributing, collection, and conveyance system)
- partial area concept
- landscape attributes
- drainage density factor
levels of protection
enhanced protection: sensitive aquatic habitats (low pre-development erosion characteristics, habitat sensitive to siltation) - end of pipe storage long-term average removal of 80% suspended solids
normal protection: less sensitive aquatic habitats (moderate, natural upstream sediment loads, spawning habitat less sensitive to siltation - end of pipe storage long-term average removal of 70% suspended solids
basic protection: areas where downstream aquatic habitat has adapted to high suspended solid loads - end of pipe storage long-term average removal of 60% suspended solids
