Stormwater Program Update

Department of Public Works and Environmental Services Working for You!

A Fairfax County, VA, publication April 14, 2021 Stormwater Program Update Project Selection and Prioritization Process Implementation Strategy

Stormwater Drivers a) MS4 Permit b) Chesapeake Bay Total Maximum Daily Load (TMDL) c) Local TMDL’s d) Dam Safety Regulations e) Maintenance of Existing Facilities f) Public Safety/Emergency Response

Accotink Tributary @ Oakford Drive Springfield District Accotink Creek WS

Stormwater Management 2 Stormwater Program Update Advertised FY 2022 Stormwater Budget 6% Emergency & 1% NVSWCD, Flood Response Labs, Towns 5% STW Regulatory

6% Stormwater (1%) NVSWCD, Occoquan Lab, Towns, $1.6 M Facility (5%) Stormwater Regulatory Programs, $4.0 M

(12%) Dam Safety and Facility Rehabilitation, $ 11.0 M

(30%) Streams and Water Quality, $26.1M

30% Operations (10%) Conveyance Systems, $9.0M 30% Streams and Water Quality (30%) Operations, $26.3 M

(6%) Emergency and Flood Response, $5.0M

(6%) Stormwater Facility $5.0M

Stormwater Management 3 Stormwater Program Update

History of Stormwater Funding $100.0

$80.0

$60.0

$40.0

$20.0Millions

$0.0

FY06 FY05 FY07 FY08 FY09 FY10 FY11 FY12 FY13 FY14 FY15 FY16 FY17 FY18 FY19 FY20 FY21 Budget Amounts Operations (General Fund) Fringe (General Fund) Public Works Construction (Fund 308) Operations, Fringe & Contributory (Fund 125)

Stormwater Management Stormwater Program Update Regulatory

• MS4 Permit Compliance • Monitoring • Industrial High Risk Runoff Inspection • Illicit Discharge Response • Outreach and Education • Stream Physical Assessment

Stormwater Management 5 Stormwater Program Update Regulatory

Stream Physical Assessment (SPA)

Stormwater Management Stormwater Program Update Regulatory

Stream Physical Assessment Subshed Ratings FY2019 & FY2020 (n=98) 40 37 35

30 28

25

20

Count 16 15 10 10 6 5 1 0 NA - No 1 - Very Poor 2 - Poor 3 - Fair 4 - Good 5 - Excellent Assessment Needed Assessment Ratings (weighted by stream length)

7 Stormwater Program Update Regulatory

8 Stormwater Program Update Regulatory

Stream Physical Assessment

Headcuts

Areas of Erosion/General

Stormwater Management Stormwater Program Update Regulatory

Stream Physical Assessment

Exposed Sanitary Sewer Collapsed MS4 outfall

Stormwater Management Stormwater Program Update Regulatory

11 Stormwater Program Update

Stormwater Management 12 Stormwater Program Update Conveyance System Rehabilitation Before `

After Stormwater Conveyance Channel In Kent Gardens Neighborhood Dranesville District Pimmit Run WS

Miller Heights Outfall Providence District Difficult Run WS

Stormwater Management 13 Stormwater Program Update Conveyance Program

7020 Bradley Circle Before Mason District

After

Stormwater Management 14 Stormwater Program Update Conveyance Program

Old Burke Lake Road Braddock District

Before After

Stormwater Management 15 Stormwater Program Update Conveyance Program

Colleen Ln Dranesville District

Before After

Stormwater Management 16 Stormwater Program Update

Conveyance System Rehabilitation `

Infrastructure Age

Stormwater Management 17 Stormwater Program Update

Conveyance System Rehabilitation, Continued ` Resident Complaints and Service Requests

1200

1000

800

600

400

200

0 FY10 FY11 (TS Lee) FY12 FY13 FY14 FY15 FY16 FY17 FY18 FY19* FY20*

Flood Related Safety Structural Maintenance Miscellaneous

Stormwater Management 18 Stormwater Program Update

Dam Safety and Facility Rehabilitation

Stormwater Facilities • 2,400 Publically Owned SWM facilities • 20 State Regulated Dams • 5,200 Private SWM facilities Typical State Dam Safety Regulation Requirements • Routine maintenance • Monthly mowing, valve exercises Before • Annual inspections After • Inspections after major storm events • Biannual inspections by a professional engineer (PE) • Non-Routine maintenance • Annual Emergency Action Plan (EAP) updates • 6-year certification cycle (Virginia) • Operation and Maintenance Plan • Inundation area mapping Lake Dredging

Maintenance of County’s flood warning system Crofton Commons Pond 1 • 20 state regulated dams, three FCPA dams, three low water crossings, Sully District one tide gate, and one pump station Cub Run WS

Stormwater Management 19 Stormwater Program Update

Dam Safety and Facility Rehabilitation

Fairfax County Stormwater Management Facility Inventory (based on inventory date)

9,000 7,677 8,000 7,452 6,924 7,000 6,537 5,942 6,142 6,000 5,587 5,270 5,270 5,015 5,088 4,769 4,727 5,000 4,454 4,410 3,973 4,102 3,734 4,000 3,523 3,185 3,379 2,941 3,000 2,407 2,197 2,364 1,969 2,040 2,127 1,747 1,853 2,000 1,513 1,584 1,636

1,000 NO. OFFACILITIES NO.

- FY2011 FY2012 FY2013 FY2014 FY2015 FY2016 FY2017 FY2018 FY2019 FY2020 FY2021 (as of 2/22/2021) YEAR

Total Private Public Linear ( Total )

Stormwater Management 20 Stormwater Program Update

Dam Safety and Facility Rehabilitation

Private SWM/BMP Inspections 1400

1269

1200

991 1000 954

881

Private Facilities Facilities Private 837

800

Legend

600 Inspections FY16 FY17 FY18 FY19 FY20 Fiscal Year

Stormwater Management 21 Stormwater Program Update Emergency and Flood Response

Tropical Storm Isaias August 2020 House on Swinks Mill Road Dranesville District July 8, 2019

Stormwater Management 22 Stormwater Program Update Emergency and Flood Response

Drainage, Erosion and Flooding Related Complaints January 1984 – February 2020

Stormwater Management 23 Stormwater Program Update Emergency and Flood Response

Unmapped Minor Floodplain Example: Dillon Avenue/Weaver Avenue

Stormwater Management 24 Stormwater Program and Watershed Management Plan Projects Update Streams and Water Quality Improvements

Flat Lick Phase I Nottoway Park Sully District Providence District Cub Run WS Accotink Creek WS

October 10, 2018 Stormwater Management 25 25 Stormwater Program Update Project Selection and Prioritization Process Implementation Strategy

1. Project Selection Priority a) Public Safety b) Regulatory (MS4 Permit) I. Chesapeake Bay TMDL II. Local Stream TMDL’s c) Community Needs

2. Existing Project Metrics a) Cost Benefit Analysis a) Overall b) Trends

Paul Springs @ Sherwood Hall 3. CIP Budget (Streams and Water Quality Mount Vernon District program) Little Hunting Creek WS

Stormwater Management 26 Stormwater Program Update

Completed Facilities FY10 - FY20

Capital Cost ($/(lb/yr) ) Number Practices Installed TN TP TSS Stream Restoration 46 $1,860 $6,270 $21 Pond Retrofits 57 $3,460 $35,500 $28 Infiltration Swales & Trenches 18 $11,300 $138,000 $190 Dry Swales 18 $5,690 $71,600 $100 Bioretention (Rain Gardens) 34 $7,640 $70,600 $95 Pervious Pavement 28 $25,800 $241,000 $305

Stormwater Managment 27 Stormwater Program Update Streams and Water Quality - Projects in Design

Stream and Outfall Restoration Pond Retrofit

Cameron Run @ LaVista Drive Lee District Cameron Run WS

Stormwater Management 28 Stormwater Program Update Dam Safety and Facility Rehabilitation Projects in Design

Pond Major Maintenance Nutley Pond Dredge Providence Kingstowne Dam Lee Lake Accotink Dredge Braddock Cavalier Woods Sec 1 0788DP Sully Circle Woods 0217DP Providence Centre Ridge 0735DP Sully Crosspointe 0771DP/0772DP Springfield Foxfield 0842DP Springfield Great Falls West PD2 1446DP Dranesville Green Trails WP0116/0816DP Sully Hampton Station 0824DP Springfield Pavilions @ Huntington Metro 1363DP Mount Vernon Pleasant Hill Regional Pond 0872DP Sully Sawdust Rd – 0264DP Sully Strawbridge – 0125DP Mason West Ox Road (EMTA) - 0047WP Springfield Lake Accotink Braddock District Accotink Creek WS

Stormwater Management 29 Stormwater Program Update Flood Mitigation Projects in Study or Design

Flood Mitigation • Briar Ridge (Dranesville) • Chowan Ave (Mason) • Dead Run Drive (Dranesville) • Gordon Ave Channel Improvements (Dranesville) • Kent Garden Neighborhood Stormwater Improvement Plan (Dranesville) • Poole Lane Overland Relief (Dranesville) • Ridgecrest Drive (Mount Vernon) • Sunset Hills Road Drainage Improvement (Hunter Mill) • Tucker Ave Neighborhood Stormwater Improvement Plan Barrett Road (Dranesville) Mason District • Tripps Run @ Barrett Road Study (Mason) July 8, 2019 • Valley Ave Drainage Improvements (Dranesville) • Weaver Ave (Dranesville)

Stormwater Management 30 Stormwater Program Update

21 Projects in Construction, Contract Award Phase or Advertisement/Bid Phase

Stream and Outfall Restoration District • Accotink Creek @ Wakefield Park Braddock • Leigh & Towlston Dranesville • Old Courthouse Spring Branch Ph Hunter Mill • Scotts Run @ Old Meadow Road Providence • Paul Spring Branch - Seg 1 @ Hollin Hills Mount Vernon • Paul Spring Branch - Seg 2 @ Hollin Hills Mount Vernon • Peyton Run @ Longwood Knolls Springfield) • Crook Branch at Mantua Elementary School Providence • Piney Run @ Lake Wereowance Dranesville • Rabbit Branch@ Collingham Dr. Braddock Pond Retrofit • Gunston Corner Wet Pond Mount Vernon • Sully Basins Sully • Center Ridge PD6 Sec 12D Sully Low Impact Development – retrofit • Mount Vernon Government Center Mount Vernon Pond Major Maintenance • Lake Barton Dredge Braddock • Terra Grande Pond and Channel Mount Vernon Lake Barton • Heritage Estates Pond 2 Sully • Weltman Estates Sully • Westwood Townes Hunter Mill • Maymont Regonal Pond D-17 Hunter Mill Lake Barton Dredge • Strawbridge Square Mason Braddock Districk Pohick Creek WS

Stormwater Management 31 Stormwater Program Update Partnership Projects

FY 2022 Planned Partnership Projects

Agency Design Construction

DPWES 4 2 FCPS 1 3 FCDOT 1 1 HCD 1 0 Total 7 6 Baileys Shelter and Community Housing Four Mile Run WS Mason District

Stormwater Management 32 Stormwater Program Update Stormwater Local Assistance Fund (SLAF)

County Stormwater Local Assistance Fund Grant Awards

• Up to 50% matching funds from State • 2014-2020 • $126 million budgeted for statewide projects • 21 County Projects Awarded • 5 Town of Vienna Projects Awarded • $21.1 Million in SLAF Grant Awards to County • $4.0 Million in SLAF Grant Awards to Town of Vienna

• FY 2021 $75 million available (Solicitation scheduled for Early June 2021) Pike Branch Tributary at Ridgeview Park Lee District Cameron Run WS

Stormwater Management 33 33 Stormwater Program Update

Progress Toward Bay TMDL FY 2010 - FY 2020

0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% 100.0% Structural Retrofits Stream Restoration TN 2006-2009 Redevelopment SFR 2009-2014 SFR Post 2014 TP PL 566 Dams Septic Conversion NMPs Land Use Change Other TSS Off-Site Credits

MS4 Permit Year 2020 2025 2030 Requirements

Stormwater Management 34 Stormwater Program Update

Stream Quality Index (SQI)

Stormwater Management 35 Stormwater Program Update

LookingLooking Forward Forward Andand onOn the the Horizon Horizon

Flood Mitigation & Resiliency Local Stream TMDLs - Sediment Inventory Growth - Chloride and Maintenance - Litter ??

New MS4 Permit 2021?? Stream Restoration Challenges and Opportunities

MS4 Permit Unregulated Area Stormwater Reuse

Stormwater Management 36 Stormwater Program Update

Before 2020 Two years after Construction Oakford Springfield District Accotink Creek WS

Stormwater Management 37 37 Stormwater Program Update

Before 2020 Three years after Construction Quander Road Outfall Mount Vernon District Little Hunting Creek WS

Stormwater Management 38 38 Stormwater Program Update

Before 2020 After Construction Snakeden Tributary at Lake Audubon Hunter Mill District Difficult Run WS

Stormwater Management 39 39 Stormwater Program Update

Before 2018 4 years after Construction Big Rocky Run Sully District Cub Run WS

Stormwater Management 40 40 Stormwater Program Update

Before 2020 2 years after Construction Turkey Run at Truro Braddock District Accotink Creek WS

Stormwater Management 41 41 Stormwater Program Update Additional Information

For additional information, please contact Craig Carinci (703) 324-5500 [email protected] www.fairfaxcounty.gov/dpwes

September 13, 2017 Stormwater Managment 42