1. THE LIFE-CYCLE COSTS AND BENEFITS OF RAIN GARDENS IN MINNESOTA Chris Hartzell & Joe Nietfeld

2. 2 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller INTRODUCTION  Rain Gardens

3. 3 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller RELEVANCE  Minnesota Push from communities and watershed management organizations to utilize rain water gardens Push from communities and watershed management organizations to utilize rain water gardens Incomplete or incomprehensible studies have been done so far regarding rain water gardens Incomplete or incomprehensible studies have been done so far regarding rain water gardens  Development Cities are encouraging developers to utilize rain gardens versus traditional storm sewer through the use of an incentive Cities are encouraging developers to utilize rain gardens versus traditional storm sewer through the use of an incentive Cities need to quantify benefit to their community Cities need to quantify benefit to their community

4. 4 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller ADVANTAGES  Advantage of Rain Gardens Cheaper to build versus traditional storm water conveyance methods Cheaper to build versus traditional storm water conveyance methods Greater beauty with a well maintained garden Greater beauty with a well maintained garden Recharges groundwater locally Recharges groundwater locally Takes pollutants out of storm water runoff Takes pollutants out of storm water runoff Return to pre-development hydrology Return to pre-development hydrology

5. 5 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller DISADVANTAGES  Disadvantage of Rain Gardens Poor construction methods allow mosquitoes to breed Poor construction methods allow mosquitoes to breed City or resident does not follow through on maintenance activities City or resident does not follow through on maintenance activities Necessity for more land Necessity for more land Loss of land value Loss of land value Only handle small storm water runoff events Only handle small storm water runoff events They don’t provide flood control They don’t provide flood control Bio-retention is started after homes are built Bio-retention is started after homes are built Long-term benefits have not been studied Long-term benefits have not been studied

6. 6 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller PROBLEM STATEMENT  Since rain gardens are a relatively new concept, little is known about their long-term maintenance costs relative to traditional storm water management practices

7. 7 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller PROBLEM STATEMENT  Infrastructure Systems Engineering (ISE) practices such as life cycle cost and cost benefit analysis could be applied to rain gardens to evaluate them over their entire life from design to construction to long term maintenance

8. 8 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller OBJECTIVE  Evaluate the effectiveness of rain gardens over their life cycles relative to a traditional storm water management system

9. 9 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller COSTS AND BENEFITS  Life Cycle Costs Design Design Construction Construction Quality Control Quality Control Long Term Maintenance Long Term Maintenance  Benefits Pollutant Removal Pollutant Removal Storm water reduction Storm water reduction

10. 10 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller PARAMETERS AFFECTING COST  Soil Conditions  Hydrology  Location  Infiltration Rates  Plant Species  Land Prices

11. 11 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller EXPECTED PRODUCT  To be used as a…  Storm Water Management Tool Municipalities Municipalities Developers Developers  Decision Making Tool Will rain gardens work in the community Will rain gardens work in the community Determine incentives to give to developers Determine incentives to give to developers “ A detailed “Best Uses” Guide showing the most effective uses of rain gardens from a life cycle perspective

12. 12 ISE 8105: Capstone Design Infrastructure Systems Engineering Instructor: Vaughn Voller QUESTIONS?