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 528

Wet pond 212 Oil Grit Separators 805

Pond Wetland 98 Proprietary Practices 239

Infiltration Basin 58 Flow Splitter 321

Infiltration 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 Materialsplants

Planning

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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