Difference between revisions of "Site assessment of residential"

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Having a comprehensive understanding of site conditions is critical for [[Screening LID Options]]
Having a comprehensive understanding of site conditions is critical for [[Screening LID Options]]
== Desktop Analysis of Background Information ==
== Desktop Analysis of Background Information ==
A thorough assessment of background information is critical to understanding site conditions for residential lots or neighborhood. As you begin gathering and reviewing background information, determine any existing infrastructure gaps and planned upgrades, resident concerns, previous community greening efforts, water usage and basement flooding. The following should be considered when conducting a desktop analysis:
A thorough assessment of background information is critical to understanding site conditions for residential lots or neighborhoods. As you begin gathering and reviewing background information, determine any existing infrastructure gaps and planned upgrades, resident concerns, previous community greening efforts, past water usage and past problems with basement flooding. The following should be considered when conducting a desktop analysis:
* Watershed studies,
* Watershed studies  
* Subwatershed studies,
* Subwatershed studies
* Stormwater master plans
* Stormwater master plans
* Sewershed delineation  
* Sewershed delineation  
* Areas with identified storm sewer capacity issues
* Areas with identified storm sewer capacity issues
* Area contributing to combined sewer overflows  
* Areas contributing to combined sewer overflows  
* Areas of degraded water quality  
* Areas of degraded water quality  
* Areas prone to flooding (both urban and riverine)  
* Areas prone to flooding (both urban and riverine)  

Revision as of 18:04, 1 December 2017

Having a comprehensive understanding of site conditions is critical for Screening LID Options

Desktop Analysis of Background Information[edit]

A thorough assessment of background information is critical to understanding site conditions for residential lots or neighborhoods. As you begin gathering and reviewing background information, determine any existing infrastructure gaps and planned upgrades, resident concerns, previous community greening efforts, past water usage and past problems with basement flooding. The following should be considered when conducting a desktop analysis:

  • Watershed studies
  • Subwatershed studies
  • Stormwater master plans
  • Sewershed delineation
  • Areas with identified storm sewer capacity issues
  • Areas contributing to combined sewer overflows
  • Areas of degraded water quality
  • Areas prone to flooding (both urban and riverine)
  • Water quality targets
  • Flow targets
  • Infiltration targets
  • The impact of planned development on existing infrastructure and watershed health
  • Source water protection plans
  • Wellhead protection areas (quantity and quality)
  • Surficial Geology
    • Soil characterization
    • Groundwater levels

Local bylaws and regulations[edit]

In addition, be sure to know the relevant local bylaws. Some LID features may contravene local regulations. Below are some examples of typical bylaws and their potential impact on LID planning:

Typical Bylaws

General Provisions May Include:

Impacts on LID Options:

Nuisance weeds and tall grass

Designates tall grass and weeds as a public nuisance

  • Defines “tall grass” as grasses over a maximum height (typically 20 – 30 cm)
  • Requires tall grass to be cut to a height not exceeding the maximum
  • Requires all nuisance weeds and weed seeds to be removed from a property by the owner.
  • The municipality may carry out the work to bring properties into
  • Compliance and recovery costs from the land owner

Vegetated LID practices may be in violation of the relevant bylaw, e.g. landscape naturalization with prairie or ornamental grasses.

Property standards

Sets minimum requirements for privately owned properties

  • Restricts low-lying areas, including those that have been excavated and accumulate water, and requires that they be drained, filled and graded so that water drains to a storm sewer or ditch.
  • Requires that all landscaped areas be cut and maintained in a reasonable condition relative to the neighboring environment

Can preclude the some LID practices, such as bioretention facilities designed be both low-lying and including ‘shallow’ surface ponding. Such bylaws can also prohibit other BMPs which rely on naturalizing landscapes.

Sewer use

Although generally limited to sanitary sewers, many municipalities now include storm water within this by-law. It generally requires all storm water be discharged to an approved outlet and regulates the contents of the discharged water.

May not permit direct discharge of roof water to the municipal storm sewer system. This can include overflow from rainwater harvesting tanks and similar devices.

Standing water

Prevents accumulation of water on an individual property within any depression

  • Often in response to mosquito breeding and West Nile Virus concerns.
  • Accumulation is typically defined by a determined period of time (e.g. 48 hours)

Soakaways, subsurface storage facilities, bioretention and bioswales may be prohibited.

Boulevard planting

Regulates the type of vegetation that can be planted within the boulevard area

Bio-swales or vegetated swales may be constrained by plant-type and plant-height restrictions along municipal boulevards

Roof leader policies (often part of property standards bylaws)

Regulates the collection and allowable discharge location of roof drainage

  • May specify outlet distance from building foundation and may prohibit discharge to storm sewers, impervious surfaces and property boundaries

Progressive roof leader policies can encourage the implementation of rain gardens, soakaways, rain barrels, and other LID practices.


Field Reconnaissance[edit]

After concluding a desktop analysis, visiting the neighbourhood in question for field reconnaissance may be ideal. Be sure to look for:

  • Neighbourhood characteristics – general impressions
  • General lot characteristics
    • % of property coverage by house
    • Driveway sizes
    • Driveway types (% of asphalt, gravel, block pavers, etc.)
    • % of property covered by turf
    • % of property covered by alternative landscaping
    • % of property covered by trees
    • Location and general condition of gardens
    • Distribution and coverage of natural vegetation
    • Location of septic systems
    • Fencing style and location
    • Prevalence of irrigation systems
    • Roadside swales
    • % curb
  • Drainage characteristics
  • Rooftop / drainage characteristics
  • Best management practices info

Once the analysis is complete, proceed to developing a list of recommended actions.