8,255
edits
Changes
Jump to navigation
Jump to search
mLine 4:
Line 4: − + Line 10:
Line 10: − + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + +
→Fit the design to the terrain
==Strategies==
==Strategies==
===Fit the design to the terrain===
===Fit the design to the terrain===
Using the terrain and natural drainage as a design element is an integral part to creating a hydrologically functional landscape.<ref>Prince George’s County. 1999. Low Impact Development Design Strategies: An Integrated Design Approach. Prince George’s County, MD.</ref> Fitting development to the terrain will reduce the amount of clearing and grading required and the extent of necessary underground drainage infrastructure. This helps to preserve pre-development drainage boundaries which helps to maintain distribution of flows. Generally, siting development in upland areas will take advantage of lowland areas for conveyance, storage, and treatment.
Using the terrain and natural drainage as a design element is an integral part to creating a hydrologically functional landscape.<ref>Prince George’s County. 1999. Low Impact Development Design Strategies: An Integrated Design Approach. Prince George’s County, MD.</ref> Fitting development to the terrain will reduce the amount of clearing and [[grading]] required and the extent of necessary underground drainage infrastructure. This helps to preserve pre-development drainage boundaries which helps to maintain distribution of flows. Generally, siting development in upland areas will take advantage of lowland areas for conveyance, storage, and treatment.
===Open space and clustered development===
===Open space and clustered development===
===Street network designs===
===Street network designs===
Certain roadway network designs create less impervious area than others. Figure 3.2.3 from the Canadian Mortgage and Housing Corporation (2002) demonstrates that loop and cul-de-sac street patterns require less area for streets. These layouts by themselves may not achieve the many goals of urban design. However, used in a hybrid form together or with other street patterns, they can meet multiple urban design objectives and reduce the necessary street area.<ref>Canadian Mortgage and Housing Corporation (CMHC). 2002 (Revised 2005, 2007). Residential Street Pattern Design. Research Highlight: Socio-Economic Series 75.</ref>A study comparing different road network designs for a hypothetical community showed a fused grid pattern can reduce impervious cover by 4.3% compared to a traditional neighbourhood design.<ref>Canadian Mortgage and Housing Corporation (CMHC). 2007. Research Highlight: A Plan for Rainy Days: Water Runoff and Site Planning. Socioeconomic Series 07-013. Ottawa, ON.</ref>
{| class="wikitable" style="float:right; margin-left: 10px;"
|-
|+ Figure adapted from CMHC (2007)
!
!Square grid
!Fused grid A
!Fused grid B
!Fused grid C
!Fused grid D
|-
!
|[[File:Square Grid.png|frameless|upright=0.35]]
|[[File:VFGA.png|frameless|upright=0.35]]
|[[File:VFGB.png|frameless|upright=0.35]]
|[[File:VFGC.png|frameless|upright=0.35]]
|[[File:VFGD.png|frameless|upright=0.35]]
|-
|Percent of area for streets
|35.0 %
|27.4 %
|27.4 %
|23.7 %
|23.7 %
|-
|Percent of buildable area
|60.0 %
|63.6 %
|64.3 %
|68.0 %
|68.0 %
|-
|Percent of open space
|5 % required
|9.0 %
|8.3 %
|8.3 %
|8.3 %
|}
Certain roadway network designs create less impervious area than others. The figure from the Canadian Mortgage and Housing Corporation (2002) demonstrates that loop and cul-de-sac street patterns require less area for streets. These layouts by themselves may not achieve the many goals of urban design. However, used in a hybrid form together or with other street patterns, they can meet multiple urban design objectives and reduce the necessary street area.<ref>Canadian Mortgage and Housing Corporation (CMHC). 2002 (Revised 2005, 2007). Residential Street Pattern Design. Research Highlight: Socio-Economic Series 75.</ref>A study comparing different road network designs for a hypothetical community showed a fused grid pattern can reduce impervious cover by 4.3% compared to a traditional neighbourhood design.<ref>Canadian Mortgage and Housing Corporation (CMHC). 2007. Research Highlight: A Plan for Rainy Days: Water Runoff and Site Planning. Socioeconomic Series 07-013. Ottawa, ON.</ref>
===Reduce roadway setbacks and lot frontages===
===Reduce roadway setbacks and lot frontages===
The lengths of setbacks and frontages are a determinant for the area of pavement, street, driveways, and walkways, needed to service a development. Municipal zoning regulations for setbacks and frontages have been found to be a significant influence on the production of stormwater runoff. A study of residential parcels in Madison, Wisconsin found that reducing setbacks by 3 m and frontages by 5.5 m resulted in a 14% reduction of stormwater runoff.<ref>Stone, B. and Bullen, J. 2006. Urban Form and Watershed Management: How Zoning Influences Residential Stormwater Volumes. Environmental and Planning
The lengths of setbacks and frontages are a determinant for the area of pavement, street, driveways, and walkways, needed to service a development. Municipal zoning regulations for setbacks and frontages have been found to be a significant influence on the production of stormwater runoff. A study of residential parcels in Madison, Wisconsin found that reducing setbacks by 3 m and frontages by 5.5 m resulted in a 14% reduction of stormwater runoff.<ref>Stone, B. and Bullen, J. 2006. Urban Form and Watershed Management: How Zoning Influences Residential Stormwater Volumes. Environmental and Planning
B: Planning and Design. 33: 21-37.</ref>
B: Planning and Design. 33: 21-37.</ref>
==References==
[[category: planning]]
[[category: planning]]