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--- site_and_regional_planning [2022/05/03 15:07] – created admin
+++ site_and_regional_planning [2026/02/09 10:39] (current) – [Case Example: St. Fancis Addition to the Village of Cross Plains] megan_duffy
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 *//Restore soil permeability//.  Use practices such as deep tilling, chisel plowing and incorporating organic matter into the upper soil layer to restore soil infiltration capacity on heavily disturbed sites.  When soil is compacted its capacity to infiltrate water is greatly diminished.  On heavily disturbed sites where practices are used to restore soil permeability, the county may waive the requirement to lower the soil permeability class rating in hydrologic calculations.  Compaction mitigation is required when disturbed green space is included in recharge calculations.
 *//Minimize directly connected impervious area//.  Downspouts and driveways should be directed to pervious areas, where feasible.  This reduces the directly connected impervious area, promotes infiltration and reduces the velocity of runoff water.  Other strategies for minimizing connected impervious area include directing sheet flow through vegetated areas and locating impervious areas so they drain to vegetated buffers or other pervious areas.
-*//Use bioretention and other practices to increase infiltration//.  [[Bioretention basin|Bioretention basins]] are engineered practices that use natural processes, including microbial soil processes, infiltration, and evapotranspiration to improve stormwater quality.  [[rain garden|Rain gardens]], often very attractive, are one type of practice commonly designed for residential lots to soak up rainwater from roofs, driveways, and lawns. [[infiltration trench|Rock trenches]] or rock beds can also be used as a conduit to more permeable layers with higher percolation rates.
+*//Use bioretention and other practices to increase infiltration//.  [[Bioretention device|Bioretention devices]] are engineered practices that use natural processes, including microbial soil processes, infiltration, and evapotranspiration to improve stormwater quality.  [[rain garden|Rain gardens]], often very attractive, are one type of practice commonly designed for residential lots to soak up rainwater from roofs, driveways, and lawns. [[infiltration trench|Rock trenches]] or rock beds can also be used as a conduit to more permeable layers with higher percolation rates.
-=====Case Example: St. Fancis Addition to the Village of Cross Plains=====
+=====Case Example: St. Francis Addition to the Village of Cross Plains=====
 The St. Francis Addition is a 72-acre, 80-lot subdivision in the Village of Cross Plains that demonstrates good site planning.  Brewery Creek, a cold-water community and a tributary to the cold-water community of Black Earth Creek, runs through the site.  During the site planning process, hydric soils to be avoided were mapped, as well as permeable soils where infiltration practices could be located.  A soil permeability analysis was prepared for the preliminary plat, identifying the ideal locations for infiltration practices. Following the site analysis, a site plan was prepared which incorporated the following practices:
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 Many of the practices and techniques discussed above are commonly referred to as “conservation design” or “low-impact design.”  Figure 2 compares a conventional subdivision layout with a subdivision incorporating conservation design practices.  During plan review, conservation design and other practices will be evaluated to ensure that the plan meets or exceeds ordinance requirements.  Less imperviousness results in less runoff to treat or store, resulting in smaller structural practices needed to comply with requirements, resulting in lower development costs (related to structure size).  Reducing peak rate and runoff volume also means less land will need to be set aside for peak rate and volume control which may result in less engineering design, and may contribute to lower development costs.
-[[File:/Images/Subdivision.PNG]]
+[{{ :subdivision.png?600 |Conventional subdivision layout (left) and conservation subdivision layout (right)}}]
-====Figure 2: Conventional subdivision layout (left) and conservation subdivision layout (right)====
 Dane County encourages conservation design by providing incentives in the ordinance for features commonly associated with conservation or low impact practices.  When developers incorporate such practices, they reduce the runoff that needs to be treated by other engineered practices.  Limiting the disturbed area may reduce construction costs and minimize the need for erosion control practices.
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 Dane County’s Erosion Control and Stormwater Management Ordinance does not prohibit regional treatment for stormwater management.  A regional stormwater treatment facility can increase efficiency of treatment and ease maintenance.  These facilities improve sediment trapping with a larger pool of water in the detention pond, and avoid problems that can arise from many smaller on-site treatment facilities all releasing water at the same time.  Regional facilities, however, are not adequate for meeting the soil loss standard during land disturbance and may not be the best strategy for stormwater infiltration.
-Cities and villages in Dane County that have adopted regional stormwater plans may want to establish a “fee-in-lieu” program and identify its requirements in their ordinances.  Fee-in-lieu programs allow developers to pay a fee rather than install on-site control measures where these may not be desirable.  The fee is put into a dedicated fund to recoup the costs for construction, operation, and maintenance of regional or multipurpose detention facilities. **Fee-in-lieu may not be used as an alternative to meeting the county’s minimum standards.**
+Cities and villages in Dane County that have adopted regional stormwater plans may want to establish a “fee-in-lieu” program and identify its requirements in their ordinances.  Fee-in-lieu programs allow developers to pay a fee rather than install on-site control measures where these may not be desirable.  The fee is put into a dedicated fund to recoup the costs for construction, operation, and maintenance of regional or multipurpose detention facilities.
+:!: Fee-in-lieu may not be used as an alternative to meeting the county’s minimum standards.
 Dane County’s ordinance allows municipalities that establish a fee-in-lieu program to allow owners of sites served by an off-site stormwater management facility to pay a fee-in-lieu of on-site control.  However, the ordinance requires that these municipalities only allow this if the regional facility is in place at the time of land disturbance, is designed and adequately sized to provide a level of stormwater control capable of meeting county standards, and has a legally-obligated entity responsible for its long-term operation and maintenance.  Regional facilities must be in place at the time of land disturbance to prevent situations where a landowner pays a fee-in-lieu of on-site control, yet the regional facility is never built, or built after a delay of years, resulting in uncontrolled and untreated stormwater runoff.