This exercise consists of an undeveloped area and two different plans for development. Review each development plan and score using the iswm Point System for integrated Site Design Practices. Note that the information is somewhat limited to represent the amount of information typically available at the Concept Review stage. Answer as best you can with the information presented. Proposed Development Site Existing Conditions Total area of site is 28 acres 17 acres are covered with trees and a small creek All C and D soil types Not within a FEMA floodplain Step 1. Determine how many points would be required circle the Minimum Required Points based on your analysis of the site: Table.4 integrated Site Design Point Requirements (excerpt) Percentage of Site(by Area) with Natural Features Prior to Proposed Development Minimum Required Points for Water Quality Protection (WQP) > 50% 50 20 50% 0 < 20% 20
Step 2. Fill out Table.5 on the following page based on your analysis of Development Plan # 1. Development Plan #1 8 total lots Curb and gutter streets of standard width Inlets and pipe system shown in pink 9. acres to remain natural
Development Plan #1 Table.5 Point System for integrated Site Design Practices (excerpt) Percent of iswm Eligible Practice Practice Area Using Maximum No. Practice Points Conservation of Natural Features and Resources 1 Preserve/Create Undisturbed Natural Areas 8 2 Preserve or Create Riparian Buffers Where Applicable 8 Avoid Existing Floodplains or Provide Dedicated Natural Drainage Easements 8 4 Avoid Steep Slopes Actual Points Earned (% practice used * max. points) 5 Minimize Site on Porous or Erodible Soils Lower Impact Site Design 6 Fit Design to the Terrain 4 7 Locate Development in Less Sensitive Areas 4 8 Reduce Limits of Clearing and Grading 6 9 Utilize Open Space Development 8 Incorporate Creative Design (e.g. Smart 10 Growth, LEED Design, Form Based Zoning) 8 Reduction of Impervious Cover 11 Reduce Roadway Lengths and Widths 4 12 Reduce Building Footprints 4 1 Reduce the Parking Footprint 5 14 Reduce Setbacks and Frontages 4 15 Use Fewer or Alternative Cul de Sacs 16 Create Parking Lot Stormwater Islands 5 Utilization of Natural Features 17 Use Buffers and Undisturbed Areas 4 18 Use Natural Drainageways Instead of Storm Sewers 4 19 Use Vegetated Swale Design 20 Drain Runoff to Pervious Areas 4 Subtotal Actual site points earned 100 Step. Compare the Actual site points earned from Table.5 with the Minimum Points Required from Table.4. Does Development Plan #1 meet the requirements? Yes No
Step 4. Fill out Table.5 on the following page based on your analysis of Development Plan # 2. Development Plan #2 80 total lots Natural drainage easements left open Alternative cul de sacs used Drainage swales between houses 1 acres to remain natural Standard street widths are used
Development Plan #2 Table.5 Point System for integrated Site Design Practices iswm Practice No. Practice Conservation of Natural Features and Resources Percent of Eligible Area Using Practice Maximum Points 1 Preserve/Create Undisturbed Natural Areas 8 2 Preserve or Create Riparian Buffers Where Applicable 8 Avoid Existing Floodplains or Provide Dedicated Natural Drainage Easements 8 4 Avoid Steep Slopes Actual Points Earned (% practice used * max. points) 5 Minimize Site on Porous or Erodible Soils Lower Impact Site Design 6 Fit Design to the Terrain 4 7 Locate Development in Less Sensitive Areas 4 8 Reduce Limits of Clearing and Grading 6 9 Utilize Open Space Development 8 Incorporate Creative Design (e.g. Smart 10 Growth, LEED Design, Form Based Zoning) 8 Reduction of Impervious Cover 11 Reduce Roadway Lengths and Widths 4 12 Reduce Building Footprints 4 1 Reduce the Parking Footprint 5 14 Reduce Setbacks and Frontages 4 15 Use Fewer or Alternative Cul de Sacs 16 Create Parking Lot Stormwater Islands 5 Utilization of Natural Features 17 Use Buffers and Undisturbed Areas 4 18 Use Natural Drainageways Instead of Storm Sewers 4 19 Use Vegetated Swale Design 20 Drain Runoff to Pervious Areas 4 Subtotal Actual site points earned 100 Step 5. Compare the Actual site points earned from Table.5 with the Minimum Points Required from Table.4. Does Development Plan #2 meet the requirements? Yes No
Exercise Answer Step 1. Determine how many points would be required circle the Minimum Required Points based on your analysis of the site: = 60.7% Using Table.4, a site with 60% existing natural features would need to score at least 50 points for Water Quality Protection. Table.4 integrated Site Design Point Requirements (excerpt) Minimum Required Points Percentage of Site(by Area) with for Water Quality Natural Features Prior to Proposed Protection Development (WQP) > 50% 50 20 50% 0 < 20% 20 Note regarding Steps 2 through 5 on the following pages: The entries provided in the tables reflect estimates based on the limited data provided for the exercise, which is generally intended to simulate the Concept Plan Review stage where information about the site and proposed development plans may be somewhat vague. Since the information is incomplete, your answers may not agree with those provided in the tables. In addition, more extensive training of plan review staff is necessary to effectively implement the Point System in jurisdictions.
Step 2) Fill out Table.5 based on your analysis of Development Plan # 1. Development Plan #1 Table.5 Point System for integrated Site Design Practices (excerpt) Percent of iswm Eligible Practice Practice Area Using Maximum No. Practice Points Conservation of Natural Features and Resources Actual Points Earned (% practice used * max. points) 1 Preserve/Create Undisturbed Natural Areas % 8 2.64 2 Preserve or Create Riparian Buffers Where Applicable 10% 8 0.8 Avoid Existing Floodplains or Provide Dedicated Natural Drainage Easements 0% 8 0 4 Avoid Steep Slopes 90% 2.7 5 Minimize Site on Porous or Erodible Soils Lower Impact Site Design 0% 0 6 Fit Design to the Terrain 0% 4 0 7 Locate Development in Less Sensitive Areas 0% 4 0 8 Reduce Limits of Clearing and Grading 0% 6 0 9 Utilize Open Space Development 0% 8 0 Incorporate Creative Design (e.g. Smart 10 Growth, LEED Design, Form Based Zoning) 0% 8 0 Reduction of Impervious Cover 11 Reduce Roadway Lengths and Widths 0% 4 0 12 Reduce Building Footprints 0% 4 0 1 Reduce the Parking Footprint 0% 5 0 14 Reduce Setbacks and Frontages 0% 4 0 15 Use Fewer or Alternative Cul de Sacs 0% 0 16 Create Parking Lot Stormwater Islands 0% 5 0 Utilization of Natural Features 17 Use Buffers and Undisturbed Areas 0% 4 0 18 Use Natural Drainageways Instead of Storm Sewers 0% 4 0 19 Use Vegetated Swale Design 0% 0 20 Drain Runoff to Pervious Areas 0% 4 0 Subtotal Actual site points earned 100 6.14 Step. Compare the Actual site points earned from Table.5 with the Minimum Points Required from Table.4. Does Development Plan #1 meet the requirements? Yes No
Step 4) Fill out Table.5 based on your analysis of Development Plan # 2. Development Plan #2 Table.5 Point System for integrated Site Design Practices (excerpt) Percent of iswm Eligible Practice Practice Area Using Maximum No. Practice Points Conservation of Natural Features and Resources Actual Points Earned (% practice used * max. points) 1 Preserve/Create Undisturbed Natural Areas 46% 8.7 2 Preserve or Create Riparian Buffers Where Applicable 50% 8 4 Avoid Existing Floodplains or Provide Dedicated Natural Drainage Easements 100% 8 8 4 Avoid Steep Slopes 100% 5 Minimize Site on Porous or Erodible Soils Lower Impact Site Design 0% 0 6 Fit Design to the Terrain 100% 4 4 7 Locate Development in Less Sensitive Areas 0% 4 0 8 Reduce Limits of Clearing and Grading 10% 6 0.6 9 Utilize Open Space Development 50% 8 4 Incorporate Creative Design (e.g. Smart 10 Growth, LEED Design, Form Based Zoning) 0% 8 0 Reduction of Impervious Cover 11 Reduce Roadway Lengths and Widths 0% 4 0 12 Reduce Building Footprints 0% 4 0 1 Reduce the Parking Footprint 0% 5 0 14 Reduce Setbacks and Frontages 0% 4 0 15 Use Fewer or Alternative Cul de Sacs 100% 16 Create Parking Lot Stormwater Islands 0% 5 0 Utilization of Natural Features 17 Use Buffers and Undisturbed Areas 100% 4 4 18 Use Natural Drainageways Instead of Storm Sewers 100% 4 4 19 Use Vegetated Swale Design 100% 20 Drain Runoff to Pervious Areas 100% 4 4 Subtotal Actual site points earned 100 46. Step 5. Compare the Actual site points earned from Table.5 with the Minimum Points Required from Table.4. Does Development Plan #2 meet the requirements? Yes No
Answer Discussion Based upon the answer provided above, neither development proposal met the minimum requirements based on the designs and information presented. Development Plan 2; however, was clearly closer to meeting the minimum score and could likely meet the minimum with minor adjustments as the project progressed to the Preliminary Plan Review stage. The Concept Plan Review meeting provides an opportunity to discuss the project with the applicant at an early stage, determine an initial project score, and provide input on potential modifications necessary to improve project performance before significant investments in design and engineering have been incurred.