Session 4 Retrofit Costs, Delivery and
Maintenance
1. Comparative Costs of Retrofitting2. Tips on Retrofit Delivery3. Incentive Programs for Residential LID
Retrofits4. Retrofit Maintenance, Tracking and
Verification
Session 4 Agenda
Key Resources on your Disc
• Appendix E of Stormwater Retrofit Practices• Cost Info in Retrofit Profile Sheets in Chapter 2 of Manual
The Costs of Retrofitting
Retrofit Construction Costs for Existing BMPs (per impervious acre treated)
BMP Conversions: 5 to 15 KBMP Enhancements: 5 to 10 K BMP Restoration: 2 to 5 K
Less excavation, modify plumbing, own or control land, strong neighborhood support
We Love These Guys !
Thirty Years of BMPs. The BMP Inventory in a Maryland County (2006)
Potentially High Performers Known Low Performers
Bioretention/Dry Swales
49 Underground Detention
270
Sand Filters 279 Dry Ponds 528Wet pond 212 Oil Grit Separators 805Pond Wetland 98 Proprietary Practices 239Infiltration Basin 58 Flow Splitter 321Infiltration Trench 459 Other (plunge pools) 30
Grand Total 3350
Dealing with the Local BMP Legacy
Comparative New Retrofit Construction Costs * (per impervious acre treated)
New Retrofits: 12 to 30 KNon-residential LID: 40 to 80 K *Residential LID: 80 to 120 K * Green Streets: 100 to 150 K *
* Demonstration project phase, should drop
• Enormous variation within each retrofit category depending on site conditions
• These estimates represent the “25% easiest”
• Major influence of the “prototype effect”
• CSN to do retrofit cost survey in 2012 2013 to get better estimates
Caveats on Retrofit Cost Numbers
1. Discovery Costs2. Project Evaluation Costs 3. Design, Engineering and Permitting4. Contracting5. Construction6. Retrofit Maintenance
Breakdown of Retrofit Costs
• Cost to identify candidate sites for potential retrofits
• Involves desktop GIS analysis and subsequent field investigation
• Two options: 1. Comprehensive subwatershed
evaluation 2. Limited assessment of existing BMP
inventory
Discovery Costs
• Usually done by consultant, but can be done in house
• For a ten square mile subwatershed, plan on:
• 200 hours for comp subwatershed eval.• 40 hours for BMP inventory assessment
Discovery Costs
• Cost to evaluate project feasibility, develop concept design and compute reductions
• Rule of Thumb: 10 to 20 hours per site
• Based on Recent CWP fieldwork
• Requires some engineering review and neighborhood consultation
Project Evaluation Costs
What is Fixed •Wetland permitting•Off-site haul of excavated materials•Sewer or utility relocation•Need easements or contested ROW•Complicated plumbing (flow splitters)•Parking, maintenance of traffic•Amenity landscaping•Others ?
Take care in the stream corridor !
Retrofit Cost Inflators
• Typically run be 30 to 50% of retrofit construction cost
• High end: “demonstration” projects, refiguring plumbing, unfamiliar practices
• Low end: Conversion, enhancement or restoration of existing BMPs
Design, Engineering and Permitting Costs
Contract Administration Costs
• Assume that 1 FTE is needed for every 1 to 2 million contracted in retrofit capital budget
• Project bundling, design/build, call contracts, bid incentives and other project management tools can reduce costs and improve quality
Discussion
General Tips on Local Retrofit
Delivery
Tip 1. Develop multiple revenue streams and delivery mechanisms
• Capital Improvement Budget• Stormwater Offset Fees• Stormwater Utility Discounts• Stormwater Maintenance Budgets• Maintenance Enforcement• Street Reconstruction • Piggyback on Municipal
Construction Projects• Public/Private Partnerships• Trading
Another slice of restoration
A slice of restoration
Tip 2. Maximize Drainage Area Treated by Individual Retrofits
• Large storage retrofits are usually the most cost effective solution
• They do require more permitting, easements and neighborhood consultation
• Experience has shown that storage retrofits can treat up to 20 to 30% of subwatershed area in suburban areas, much less in highly urban ones
• Green street and on-site LID retrofits are needed for the next chunk of treatment
Tip 3. Residential LID Retrofit Incentives
Subsidies, technical assistance, stormwater utility credits and other incentives to build LID retrofits on private land
Tip 4. Transform Your Stormwater Maintenance Program
Use your stormwater maintenance inspection, tracking and enforcement authority to identify potential retrofits and/or major maintenance upgrades
Potential for both public and private stormwater facilities
Discussion
Incentive Programs for Residential
LID Retrofits
Some Pioneer ProjectsChesapeake Bay Demonstration Projects
• Alliance for the Chesapeake Bay• Blue Water Baltimore• Center for Watershed Protection• Corsica River Conservancy • DC River Smart Homes• Gunpowder River Conservancy• Montgomery County Rainscapes Rewards• Watershed Stewards Academy• Arlington, VA• Gaithersburg, MD• Rockville, MD
Programs Elsewhere in the Country
•Portland, Seattle, Toronto, Kansas City
Watershed Retailer Case StudyBlue Water Baltimore
Funding: NFWF Grant and Baltimore City ContractOutreach: Two staff w/neighborhood specific outreach Targeting: Two subwatersheds and priority neighborhoodsDesign: Outdoor Water Audit by BWB staffInstallation: By BWB staff or contractorLID Goal: 2000 - predominately disconnections *Tracking: Post Construction Inspection Notes: Runs own native plant nursery
Website: http://www.bluewaterbaltimore.org/programs/clean-waterways/waterauditprogram/
BLUE WATER BALTIMORE “RAINFALL RECYCLING” SUBSIDIES Practice Installation Materials
plantsPlanning
Limitations
Rain Barrel Free $25 off Free At least 50 gallons
Downspout Disconnection
Free Free Free Above-ground only
Rain Garden Half off up to $500
Half off up to $500
Free Treats connected impervious area
ConservationLandscaping
Half off up to $300
Half off up to $300
Free Must reduce runoff *******
Hardscape Removal
Half off up to $200
Half off up to $200
Free Must reduce runoff
Shade Tree Free $35 Free 2 per lot
Landscape Contractor RetailerCorsica River Conservancy Rain Garden Project
Funding Source: NFWF grant Incentives: Free Installation of $2000 Rain GardenTargeting: Centerville, MD, three homeowner associationDesign: 4 Local Master GardenersInstallation: CRC-designated landscape contractor Rain Gardens Installed: 250 Tracking: CRC takes before and after photos, GPS coordinates, street addressMaintenance: Simple Agreement, with annual tasks Other Notes: Several different planting templates offered
Website: http://www.corsicariverconservancy.org/activities
County Rebate ProgramMontgomery County Rainscapes Rewards
Funding Source: Stormwater UtilityIncentives: Max Rebates up to $1200 for residential and $5000
for non-residential propertiesCoordination: One staff for coordination, technical support and
review; ½ position for outreach; ½ position admin support Targeting: County wide, (RainScapes Neighborhoods targets six priority
neighborhoods through County-installed projects – One staff; ½ position outreach; ½ position admin support)
Design: Property owner responsibility but also on-line and/or onsite technical assistance available
Installation: By property owner or their contractor Tracking: Post-Construction Inspection, GIS tracking and Maintenance
InspectionOther Notes: On-line application system
Website: http://www.montgomerycountymd.gov/dectmpl.asp?url=/content/dep/water/rainscapes.asp
RainScapes projects
Photos courtesy of MC-DEP RainScapes Program
Other Stewardship Delivery Options• Delivery with Co-pays “River Smart” Homes (DDOE)• 10% Property Tax Credit (Anne Arundel County)• Discount on Stormwater Utility Fee (Philadelphia)• Disconnection Fundraiser ($50 per, Portland, OR)• Mandatory Disconnection (Toronto) • “Garden Angels” and “Stormwater Champions”
(Kansas City)
Common Problems Encountered
• High initial investment in outreach to create demand
• Hard to keep up with demand once things get going
• Shortage of trained home auditors and installers
• Reducing administrative burden for applicants
Discussion
Maintenance, Tracking and Verification of
Retrofits
Retrofit Inspections & Verification• CBP emphasizing verification of
BMPs installed for the TMDL • Procedures being developed now• The Retrofit Removal Rate is not
perpetual • Good for 10 years, and can be
renewed based on field inspections (5 years for on-site LID retrofits)
• Use of simple visual indicators • Reporting through annual MS4
reports to MDE
• 1 FTE: 250 to 500 retrofits a year
Retrofit Tracking
Integrate Retrofits into Existing Local BMP Tracking Systems
.
database (full size)
Retrofit Maintenance
Costs
Traditional BMPs: 3 to 5 % of Capital Cost Gum SurgeryLID Retrofits: 3% ? Daily Flossing
The Old Pond Maintenance Model
One big pond
The New LID Maintenance Model
24 disconnections18 swale sections14 rain gardens5 bioretention areas4 tree planting areas6 sheet flow credits
Seattle Retrofit Maintenance Case Study
Adapted from Donofrio, 2012 Seattle Public Utilities
• Two crews – Hardscape: city crew– Landscape: contractor
• Scheduled by LOS –not frequency
• Semi annual inspections– pre fall– pre spring
Maintenance Management
Adapted from Donofrio, 2012 Seattle Public Utilities
Maintenance Program is designed by
• Levels of Service• LOS A– Excellent effort
• LOS B– Good effort
• LOS C–Moderate effort
• LOS D– Poor effort
Adapted from Donofrio, 2012 Seattle Public Utilities
Layout and How To• Select the desired Service Level for maintenance
Adapted from Donofrio, 2012 Seattle Public Utilities
Questions and Answers
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