#1Advancing Stormwater Resiliency in Maryland Project Kickoff and Engagement April 2022 MARYLAND Maryland Department of the Environment#2Welcome and Housekeeping • Today's session is being recorded We have disabled microphones and turned off the video for all participants If you get bumped, lose connectivity, or your screen freezes, leave and reenter the session We ask that all questions be submitted through the Q&A function Questions will be held to the end of today's session We welcome interactive communication among participants through the chat function Maryland Department of the Environment 07.14.2016 2#314 Activities M CC 回 1. Θ 8 A Breakout rooms Split into smaller group discussions 2. Polls Get a quick pulse of the audie ① 3. ? Q&A Give everyone an easy way to ask questions Recording Record meetings for on-demand viewing Whiteboarding Collaboratively brainstorm and sketch ideas 4. + Ask a question Your name and question will be recorded 0/300 Cancel Post 3#4i g Activities 2 по 1. Breakout rooms 2. Split into smaller group discussions Polls Get a quick pulse of the audience ? Q&A Give everyone an easy way to ask questions Recording Record meetings for on-demand viewing Whiteboarding Collaboratively brainstorm and sketch ideas 3. Polls Poll 1 of 1 Poll question Answer option A Answer option B Vote Live > Maryland Department of the Environment 4#5Today's Agenda 1. Opening Remarks: Lee Currey, Director, Water and Science Administration 2. Introduction to Senate Bill 227: Les Knapp - Senior Local Advisor, Office of the Secretary Maryland Department of the Environment 3. Flooding and Existing Programs in Maryland: Jennifer Smith and Raymond Bahr - Stormwater, Dam Safety, and Flood Management Program (SDSFM) 4. Maryland's Approach to SB 227: Jennifer Smith, Raymond Bahr, Stewart Comstock, Dave Guignet, Kevin Wagner, and Brian Cooper - SDSFM 5. Next Steps: Debbie Cappuccitti - SDSFM 6. Moderator: Christina Lyerly - SDSFM 5#6The Growing Threat of Urban Flooding Maryland Department of the Environment • Purpose What we know today What we can do now The path ahead 6#7Why Are We Here? rederici Patuxent Corridor Potomac Corridor FOLLOW 201 From 2006 to 2020, more than 2,500 flood-related incidents affected state-maintained roadways in Maryland, including this Sept. 8, 2011, flood at Maryland 301 and Route 4 in Upper Marlboro, where the west branch of the Patuxent River overflowed. Jonathan Newton/The Washington Post via Getty Images Maryland Department of the Environment Severe weather events, sea level rise, and climate change are contributing to increased flooding that threatens our communities, residents, and natural heritage Flooding can be especially devastating to economically disadvantaged or historically neglected communities Local land use planning is already being informed by updated flood maps and State policies like Coast Smart Time to apply the same principles to stormwater management in our developed communities and areas subject to flooding We need work together to solve the challenge of flooding prevention and resiliency This is just the first step in a long term process that will continue into the future 7#8The Required Framework - SB 227/HB 295 of 202 Maryland Department of the Environment • MDE report outlining process for meeting bill's requirements to General Assembly in November 2021 (A-StoRM Report) • Identify most recent precipitation data available Investigate flooding events since 2000 to identify potential areas of concern Revise Maryland's stormwater quantity management standards every five years . Update other stormwater regulations as necessary every five years Think of the process as akin to updating a local comprehensive plan https://mgaleg.maryland.gov/2021RS/bills/sb/sb0227E.pdf https://mgaleg.maryland.gov/2021RS/bills/hb/hb0295T.pdf https://mde.maryland.gov/Documents/A-StorRMreport.pdf BILL 8#9Consultation Requirements Under SB 227/HB 295 The following groups shall be consulted on all proposed regulatory updates at least 6 months in advance: . The Commission on Environmental Justice and Sustainable Communities • Maryland Department of the Environment Stakeholder Group with expertise on stormwater design standards and climate science with following members: • An academic institution • The Chesapeake Bay Program • The Chesapeake Bay Commission . The Maryland Department of Emergency Management The Maryland Association of Soil Conservation Districts • Local governments • A private sector entity with design and construction experience • An association that has expertise in stormwater restoration projects In addition to the required consultations, MDE also plans to form various technical advisory groups and accept questions and comments on the A-StoRM hub 9#10Navigating the Seven "C's" of A-StoRM MDE's Approach to Meeting A-StoRM's Requirements 1. Communication - Open and transparent conversation with all interested stakeholders 2. Consultation - Solicit input from all interested stakeholders and consider received feedback 3. Collection - Utilize new scientific tools and local knowledge to improve data acquisition and analysis 4. Coordination - Incorporate and grow existing data sets and programs where feasible - no need to "reinvent the wheel" Maryland Department of the Environment Source: Pixabay 10 10#11Navigating the Seven "C's" of A-StoRM Source: Pixabay Maryland Department of the Environment MDE's Approach to Meeting A-StoRM's Requirements 5. Consistency - Apply rational and logical principles to 6. 7. both the A-StoRM process and outcomes - there should be no "surprises" Capability Recognize the different abilities and - resources of local jurisdictions and avoid a "one size fits all" mentality with respect to desired outcomes and regulatory requirements Culmination - Creation of accurate flood data, incorporation of resiliency into stormwater management regulations, and practical process for future review and potential revision of stormwater regulations 11 114#12Your Questions..... What type of flooding is MDE going to address through these efforts? What size watershed is MDE interested in when defining flooding" events? Will there be guidance on performing watershed studies to address climate change and flooding? Will MDE invite comments or feedback on state funding support for mapping or local projects? Will MDE incorporate lessons learned from local flood control project initiatives? Will MDE invite comments or feedback on proposed regulation changes? Will MDE be dictating capture and conveyance design guidelines to address urban flooding? What will the timing be for the required studies? What is the target date for forming the stakeholder group? 12 12#13Trivia Question How deep does the water need to be to float a car (feet)? a. 0.5 b. 1 C. 1.5 d. 2 Answer: One foot can carry away most cars. (Two feet can carry away SUVs and trucks.) https://www.weather.gov/safety/flood-turn-around-dont-drown Maryland Department of the Environment 13#14Ellicott City, May 27, 2018 $7 04:20:13.001 PM (EDT) 4:20 p.m. Video courtesy of Howard County Government 14#15Event Date September 10, 2020 August 21, 2018 Location Total Precipitation College Park 4.5 inches in 2.5 hours Forestville 3.18 inches in 1.0 hours September 29, 2016 September 29, 2016 July 30, 2016 Salisbury 7.41 inches overnight Catonsville, May 2018 Snow Hill و 9 inches overnight August 13, 2014 Ellicott City Queenstown 5.96 inches in 2 hours 9.92 inches in 24 hours August 13, 2014 Dundalk 8.75 inches in 24 hours August 13, 2014 Linthicum 8.03 inches in 24 hours June 13, 2014 Clear Spring inches in 2 hours City of Salisbury, 2016 15#16Historical Development Patterns • Development next to rivers/mills • Development in floodplains • Development before stormwater management requirements • Development downstream of dams https://mdfloodmaps.net 5310 YORKTOWN RD 500-Year 5202 VENTNOR RD LITTLE FALLS DR WAKEFIELD ROD 5096 MALDEN DR 5304 VENTNOR RD SMALLWOOD DR 5098 500-Year Little Falls Branch Maryland Department of the Environment Select a theme 4998 REDFORD RD DO SMALLWOOD DR 5206 LITTLE FALLS DR 5210 5212 16#17Tidal Flooding and Sea Level Rise ● Back water (tailwater) conditions Storm drain system surcharge Nuisance flood plans Coast Smart CRAB (Climate Ready Action Boundary) https://dnr.maryland.gov/ccs/coastsmart/Pages/default.aspx Maryland Department of the Environment CRAB: Climate Ready Action Boundary Horizontal I CS-CRAB I I | Newly Inundated FEMA I I Floodplain Limit I I Coast Smart Climate Ready Action Boundary (CS-CRAB) Land Sea Level FEMA 100 year Floodplain 100 year + 3ft Joppa, April 2020 CS-CRAB Elevation = BFE + 3ft FEMA Base Flood Elevation (BFE) Sea Level 3 ft Vertical Extent 17#18Aging or Undersized Infrastructure • • . . Piped urban stream systems Undersized culverts Clogged, broken, disjointed pipes and channels Inlet surcharging State and local design inconsistencies Maryland Department of the Environment https://mde.maryland.gov/programs/Water/StormwaterManagementProgram/Pages/StormwaterPrint.aspx 18#19New Development (and Redevelopment) Maryland Department of the Environment . • Environmental Site Design (ESD) to Maximum Extent Practicable (MEP) for 2.7 inches of rainfall 2/10 year quantity management for areas known to flood 100 year quantity management for interjurisdictional watersheds (Jones Falls, Gwynns Falls, Herring Run) SAFEWAY THARMACE 19#20Trivia Question Living in the 100 year floodplain means you will only flood once every 100 years a. True b. False Maryland Department of the Environment Answer: False. This is a common misconception. In fact, if you live in the flood zone, you have a 26% chance of flooding over your 30 year mortgage. A 100 year storm means there is a 1 in 100 or a 1% chance of that size storm hitting a certain area for a given year. Theoretically, a 100 year storm could hit in back to back years. https://www.weather.gov/epz/wxcalc_floodperiod 20 20#21Climate Change . "Heavy downpours are increasing nationally, especially over the last three to five decades. The largest increases are in the Midwest and Northeast. Increases in the frequency and intensity of extreme precipitation events are projected for all U.S. regions" - 2017 National Climate Assessment Use of IDF curves based on historic precipitation are likely to underestimate future precipitation - Chesapeake Stormwater Network Maryland Department of the Environment The volume of annual rainfall is expected to increase in the Chesapeake Bay Watershed by approximately 6.5% by 2055 - Chesapeake Bay Program 21 21#22Regulatory Gaps Areas Available for New Development Mapped Local Floodplain Aging Undersized Conveyance ☐ ☐ Aging Undersized Conveyance Older Development in Floodplain Maryland Department of the Environment Mapped FEMA Floodplain 22 22#23Who's Involved in Flood Management? National Oceanic and Atmospheric Administration Department of Agriculture Hazard Mitigation Grant Program Wetlands and Waterways Maryland Coast Smart Department of Natural Resources Dam Safety Programs Land Use Zoning Emergency Management Agencies Commission on Environmental Justice and Sustainable Communities Nuisance Flooding Plans Climate Change Commission Department of Planning Water Resources Element Flood Control and Watershed Management Grants Program Comprehensive Plans Federal Emergency Management Agency Watershed Management Plans Stormwater Management Programs National Flood Insurance Program Department of Emergency Management Hazard Mitigation Plans Erosion and Sediment Control Programs Department of the Environment 23#24Maryland Department of the Environment SB 227 as an Opportunity State and Federal Flood Mitigation Programs Local Planning A-StoRM • Work within existing local planning processes Not intended to duplicate the information within local hazard mitigation, comprehensive, and nuisance flooding plans Complement and expand the scope of local flood risk mitigation Integrate better with existing state and federal agencies responsible for flood management that can provide funding https://www.fema.gov/blog/disaster-mitigation-act-2000-20-years-mitigation-planning 24 24#25. . 2021 Stormwater Management Law Report on most recent precipitation data available Investigate flooding events since 2000 Update Maryland's stormwater quantity management standards Update other regulations as necessary Report to General Assembly by November 1, 2021 Maryland Department of the Environment Maryland Department of the Environment Advancing Stormwater Resiliency in Maryland (A-StoRM) Maryland's Stormwater Management Climate Change Action Plan FY 2021 Data Prepared for: Bill Ferguson, Senate President Maryland General Assembly Adrienne A. Jones, House Speaker Maryland General Assembly https://mde.maryland.gov/Documents/A-StorRMreport.pdf 25#26Maryland Department of the Environment Maryland's Recent and Future Precipitation Data 26#27Maryland's Precipitation Data Maryland Department of the Environment Precipitation Data: "historical data that describes the relationship between precipitation, intensity, duration, and return period (frequency)" • IDF curves based on Technical Paper No. 40 (TP40), Rainfall Frequency Atlas of the U.S., developed in 1961 by the United States Department of Agriculture, Soil Conservation Service • 2004 NOAA Atlas 14, Precipitation-Frequency Atlas of the United States, Volume 2 • 2025 Maryland updates to NOAA Atlas 14 with future predictions . • RAND Corporation future projected IDF curves for the Chesapeake Bay Watershed based on the current NOAA Atlas 14 Volume 2 precipitation data with a range of predictions for future climate change https://midatlantic-idf.rcc-acis.org/ 27 27#28Mid-Atlantic State Actions • • Virginia Beach (VA) – 20% increase on Atlas 14 precipitation values for new development as input into a watershed model Hampton Roads Planning District (VA) - considering incorporating a climate precipitation change factor • Virginia Department of Transportation (DOT) - 20% increase on Atlas 14 precipitation values for bridge design · Maryland Department of the Environment New York State DOT - 10-20% increase on Atlas 14 precipitation values for culvert and natural channel design - based on regions Pittsburgh (PA) - Managing post development peak flows calculated using 2100 year climate change precipitation data back to existing condition peak flows calculated using the most recent Atlas 14 precipitation data 28#29Maryland Department of the Environment Investigate Flooding Events Since 2000 29 29#30Trivia Question How many inches of fast-moving water can knock over an adult? a. 6 b. 12 c. 18 d. 24 Answer: 6 inches https://www.weather.gov/safety/flood-turn-around-dont-drown Maryland Department of the Environment 30#31Flooding Events NOAA Home Cumberland Winchester NATIONAL CENTERS FOR NNQANATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION ENVIRONMENTAL INFORMATION Contact Us About NCEI Help NCEI Storm Events Database Storm Events Database Storm Events Database Data Access Bulk Data Download Martinsburg Hagerstown Search Bulk Data Download (CSV) Storm Data Publication Documentation Database Details Version History Storm Data FAQ NOAA's NWS Documentation Tornado EF Scale External Resources NOAA's SPC Reports NOAA's SPC WCM Page NOAA's NWS Damage Assessment Toolkit Assessment NOAA's Tsunami Database ESRI/FEMA Civil Air Patrol Images SHELDUS USDA Cause of Loss Data The database currently contains data from January 1950 to December 2021, as entered by NOAA's National Weather Service (NWS). Bulk data are available in comma-separated files (CSV). These files can be viewed in Excel and other spreadsheet applications. Access: FTP/HTTP Detailed information about the fields/columns: FTP/HTTP Documentation on the file naming convention: FTP/HTTP 20 mi Staunton Privacy Policy | FOIA | Information Quality | Disclaimer | Contact Us Charlottesville Lake Anna Germantow Westminster Aspen Hill Sterling Columbia Baltimore Annapolis Reston Washington Centreville Alexandri Dale City redericksburg Wilmington Dover Delaware Bay DELAWARE Salisbury Vineland 31#32Flooding Events + 20 mi Staunton Cumberland Harrisonburg Charlottesville Winchester Martinsburg Hagerstown Frederick Germantown Westminster Aspen Hill Sterling Columbia Baltimore Annapolis Reston Bowie Washington Centreville Alexandria Dale City Aberdeen Wilmington Dover Delaware Bay DELAWARE Salisbury California Fredericksburg €3 Vineland 32#33Advancing Stormwater Resiliency in Maryland Home About Key Components ▾ Resource Library Community Engagement https://sb-227-maryland.hub.arcgis.com/ Key Project Components الالالالالامر Information Exchange Watershed Mapping and Assessment Updated Stormwater Standards $ Targeted Funding Opportunities 33#34Update Maryland's Stormwater Quantity Management Standards Maryland Department of the Environment 34#35Stormwater Management Requirements in 1982 - 2000 2 year, 10 year, Quantity Management Maryland 2000 - 2009 WQv, CPv, Quantity Management as Required 2009 - 2020 ESD to MEP, Quantity Management as Required 35#36Maryland's SW Quantity Management Standards • Environment Article Section 4-203(b): Maryland Department of the Environment "all stormwater management plans shall be designed to implement quantity control strategies to prevent increases in the frequency and magnitude of out-of-bank flooding from large, less frequent storm events." • COMAR 26.17.01.06.A.3: Quantity management for the 2-year or 10-year storm is required when the local jurisdiction "determines that additional stormwater management is necessary because historical flooding problems exist and downstream floodplain development and conveyance system design cannot be controlled." 36#37Legend Allegany Washington* Cecil Carroll Harford Garrett Frederick* Baltimore* Baltimore City Kent Howard Montgomery* Q2 and Q10 required Q2 not required, Q10 required Q2 and Q10 required at County's discretion Queen Anne's Anne Arundel Caroline Prince George's Talbot Calvert Charles Dorchester Wicomico St. Mary's Worcester Somerset Q2 not required, Q10 req at County's discretion See Below Cecil: Q2 required for Coastal Plain, Q10 required for Piedmont N Talbot: Q2 control requires post-development peak discharge rate be within 10% of pre-development peak discharge rate. Q10 not required County: Q100 required County: Q100 required at County's discretion County: Q100 not required 37#38Comprehensive Watershed Studies A-StoRM Says: Develop draft stormwater regulations that require local jurisdictions and state and federal agencies to generate comprehensive watershed studies (if funding exists) for all known flood event watersheds. The draft regulations will require local jurisdictions and state and federal agencies to use the watershed studies to develop watershed-specific flood management plans. Maryland Department of the Environment 38#39Watershed Studies & Flood Management Plans Flood Hazard Management Act of 1976 (Environment Statute $5-802) • Also known as the Comprehensive Flood Management Grant Program (CFMGP) • 27 watershed studies and flood management plans complete by 1995 https://mde.maryland.gov/programs/Water/StormwaterMa nagementProgram/FloodHazard Mitigation/Pages/Past-Pla ns.aspx ANALYSIS OF FLOODING WILLS CREEK Maryland Department of the Environment ALLEGANY COUNTY, MARYLAND March 1986 Water Resources Administration Flood Management Division Maryland Department of Natural Resources Tawes State Office Building Annapolis, Maryland 21401 39#40Garrett Allegany Washington Cecil Carroll Harford Frederick Baltimore Patapsco River Gywnns Falls Jones Falls Baltimore City Kent Howard Gunpowder Falls Upper George's Creek Montgomery Fairgo Basin Tributary to Braddock Run Queen Anne's Anne Arundel Triple Lakes PATAPSCO RIVER BASIN STUDY confesco use Brace 800 Warrior Run Wills Creek Lilly Run Flat Run Bradley Run Anacostia River Cattail Creek Fishing Creek Upper Wicomico Deep Run Watersheds with Past Comprehensive Flood Management Plans (non-exhaustive) Prince George's Talbot Caroline RECEIVED JUL 23 1980 WAL RESOURCES ADMIN. Prepared By: WATERSHED PERMITS Regional Planning Council U.S.D.A. Soil Conservation Service March 1980 Calvert Charles Dorchester Wicomico St. Mary's N Worcester merset https://mde.maryland.gov/programs/Water/StormwaterManagementProgram/FloodHazard Mitigation/Pages/Past-Plans.aspx 40 40#41Stormwater Management (SWM) and Watershed Studies • SWM designs must be consistent with MDE approved watershed studies and flood management plans. - (COMAR 26.17.02.09.B) Maryland Department of the Environment • Quantitative management redevelopment policies can be developed that differ from the minimum standards if they are part of an overall watershed management plan. — (COMAR 26.17.02.05.E) - Quantitative management waivers for new development can be granted only in areas with MDE approved watershed management plans. — (COMAR 26.17.02.05.C.(2)) • Alternative minimum control requirements must be MDE approved and be consistent with a MDE approved watershed study. (COMAR 26.17.02.08.G) • Development in watersheds designated as interjurisdictional flood hazard watersheds shall comply with flood management plans - (COMAR 26.17.02.06.C) 41#42Little Youghiogheny R Pilot Watershed Studies Gwynns Falls Oakland Round Mamanel Kegy Paw Run De Legend Mountain Lake Park Lodi Lynn Heights Maryland 12 Digit Watersheds Maryland 8 Digit Watersheds Breton Bay Grave Blacksmith Rd Glebe Run nc Breton Bay Kent Ave Kent Ave Edmond Catonsville Park Stillmeadows Community 42 42#43Watershed Studies Are the Key • Key to Understanding What Has Happened Key to Understanding What Can Happen And Key to Understanding What Changes Need to Happen Maryland Department of the Environment A W/S Study is a (Key) First Step to Unlocking State and Federal Grants for Solutions • W/S Studies Are Required for matching State CFMGP funds (and...) W/S Studies Demonstrate Understanding and Solutions for Federal BRIC and FMA Grants/Now at Historic Funding Levels / Nationally Competitive Grants... 43 33#44Available through MD Department of Emergency Management (MDEM) • • Notice of intent due AUGUST 1 to MDEM Multiple grant programs including: . • • Hazard Mitigation Grant Program (HMGP) Building Resilient Infrastructure and Communities (BRIC) Flood Mitigation Assistance (FMA) More information: mdem.maryland.gov/community/Pages/ Mitigation.aspx Source: www.fema.gov/sites/default/files/documents/fema_summary-fema-hazard-mitigation-assistance-grant-programs_032321.pdf 1. Mitigation Projects Property Acquisition Structure Elevation Mitigation Reconstruction Eligible Activities for Grants: Flood Risk Reduction Measures Stabilization Dry Flodproofing Non-Residential Buildings Tsunami Vertical Evacuation Safe Rooms Wildfire Mitigation Retrofitting Generators Earthquake Early Warning Systems Innovative Mitigation Projects 2. Capability and Capacity Building New Plan Creation and Updates Planning-Related Activities Project Scoping/Advance Assistance Financial Technical Assistance Hazard Mitigation Grant Program Hazard Mitigation Grant Program - Post Fire Maryland Department of the Environment Building Resilient Flood Mitigation Infrastructure and Communities Assistance . • • • • • • • • . • ° • • • • • 44#45Other Funding Opportunities... sb-227-maryland.hub.arcgis.com/pages/targeted-funding-opportunities Advancing Stormwater Resiliency in Maryland Home About Key Components - Resource Library Targeted Funding Opportunities Maryland Department of the Environment Goal: Updating local stormwater and flood management programs will require budgeting for planning and project implementation. Funding is also necessary for comprehensive watershed studies, data collection, and tools to identify causes and actions to mitigate flooding. MDE will help local jurisdictions identify funding opportunities that may support efforts related to comprehensive planning, development of watershed studies and engineering analyses, and stormwater best management practices (BMP) for additional quantity management. Approach: MDE will compile funding resources related to flood management.. Grant Information This database contains more than 200 federal, state, and private foundation grants related to hazard mitigation, floodplain management, green infrastructure, improving water quality, and additional adjacent disciplines. It is searchable by key words. You do not need to register to use the database. Registration is free and those that register will receive a quarterly email identifying open grants. If you want to add/curate a grant, admin privileges would be required. To do so, please CLICK HERE to register and login (opens in a separate window). This database is actively being updated. Therefore, information contained within is subject to change. Home Maryland ENVIRONMENTAL SERVICE About DATABASE OF GRANTS Register Database of Grants -Interactive Search Portal Enter or select search values in one or more text box or dropdown search fields below Note: Wild card characters are not supported in your search values but partial values are. It may take around 30 seconds to return results Use the tool below to explore currently available funding opportunities: Program Name: Grant Subject: Click here for grant subject information (PDF) Last Updated: No Filter Cost Share Type: No Filter ✓ Agency Name Funding Type: No Filter Search 45#4646 46 SWM Quantity Management Questions What precipitation data should we be using for SWM design storm? Existing precipitation or future climate change projections Maryland Department of the Environment Shorter duration storm events (e.g., 3 hour or 6 hour), or continue using 24 hour storm data, or both What type of quantity management design criteria should we be considering? . Statewide quantity mandates for all new development, redevelopment Additional requirements for watersheds with known flooding events New watershed studies and flood management plans be mandated jurisdiction-wide How do we ensure that new criteria do not make flooding worse?#47Projected Atlas 14 Change Factors* (%) Maryland Department of the Environment 1.09 1.11 1.08 1.14 1.13 1.13 1.11 1.12 1.09 1.10 1.09 1.08 1.10 1.09 Minimum: 1.07% Average: 1.10% 1.08 1.07 Maximum: 1.14% 1.08 1.09 1.08 Based on these projections, the ESD volume also should increase by 10%, or 3.0 inches (0.25 feet) 1.09 1.09 1.11 1.10 *Based on the Marisa “Projected Intensity-Duration-Frequency (IDF) Curve Data Tool for the Chesapeake Bay Watershed and Virginia" 17 47#48Regulatory Changes: Environmental Site Design (ESD) • • .• ESD is required by law [Env. Art. §4-203(b)(2)] Considering updates to ESD to Maximum Extent practicable (MEP) to capture increased runoff volumes based on future climate projections Goal is to capture, treat, and slowly release sufficient runoff to mimic natural conditions and address the Rev, WQv, and Cpv Was derived from the median one year 24-hour storm, or 2.7" (Cpv) Climate change projections do not include one year storms. The projected change for larger design storms (e.g., 2, 5, 10 yr) is 10% and the average rainfall volume is increasing by 6.5% Using these projections, ESD should change from 2.7" to 3.0" The ESD minimum would still be 1.0 inch 2000 MARYLAND Maryland Department of the Environment STORMWATER DESIGN MANUAL VOLUMES I & II PREPARED BY: CENTER FOR 0000 Tun, Munc AND THE MARYLAND DEPARTMENT OF TE ENVIRONMENT WATER MANAGEMENT ADMINISTRATION MDE 2500 BRNING HIGHWAY BALTIMORE MARYLAND 21224 (410) 631-3543 1-800-633-6101 hrp://www.mde.state.md.us 48#49ESD and Shorter Duration Storms 3.21 2.45 2.64 10 Year 6 hour Storms 3.77 3.77 3.63 3.68 Minimum: 2.45 in. Average: 3.62 in. 3.65 Maximum: 4.07 in. 3.77 3.90 3.88 3.96 3.93 4.07 *Based on the Marisa “Projected Intensity-Duration-Frequency (IDF) Curve Data Tool for the Chesapeake Bay Watershed and Virginia" 3.93 Maryland Department of the Environment 49#50Timeframe for Regulatory Changes • The Design Manual was developed over five years: MDE started the project in 1995 • • Maryland Department of the Environment The first draft of the Design Manual was published in 1997 The final draft and associated regulations were adopted in October 2000 In 2007, MDE started on the supplement to the Design Manual to incorporate ESD. This abbreviated process led to the incorporation of Supplement 1 and new regulations in 2009 It's 2022 now... 50 50#51Additional SWM Regulations • . Require 10-year quantity management with a twist, using future precipitation data and volumes, and managing them back to historical 10-year precipitation data and volumes Require watershed studies in areas experiencing flooding and specific quantity management based on unique watershed characteristics • Investigate requirements for quantity management for redevelopment . Review regulations for updates every 5 years Maryland Department of the Environment 51#52Other Regulations • Floodplain regulations Dam safety regulations Nuisance flooding regulations Comprehensive Flood Management Grant Program Other Programs Maryland Department of the Environment Local Comprehensive Plans - new guidance for the water resources element and stormwater management, including the consideration of development upstream/downstream of dams Hazard Mitigation Plans - begin incorporating more information on urban (pluvial) flooding 52 52#53Trivia Question Floods are the most common natural disaster a. True b. False Maryland Department of the Environment Answer: True. According to the World Health Organization, floods are the most common disaster in the world and are increasing in frequency and intensity. https://www.who.int/health-topics/floods#tab=tab_1 53#54How SB 227 Can Enhance Floodplain Management • 147 communities participate in FEMA's National Flood Insurance Program (NFIP) in Maryland • 16 participate in the NFIP's Community Rating System (CRS) Any community can adopt higher regulatory standards • Benefits: Reduced flood risk, additional CRS credit/lower flood insurance premiums (e.g., Stormwater Management, Floodplain Management Planning, Drainage System Maintenance, Flood Warning and Response, Dams) Maryland Department of the Environment NATIONAL FLOOD INSURANCE PROGRAM NFIP/CRS 54 54#55A-StoRM HUB: Why Information Exchange? • The HUB will include an overview of Existing Local Flood Management Policies and Planning Tools: Local Hazard Mitigation Plans (HMP) • Identify flood hazard areas (as well as multi-hazards) • Mitigation strategies and priorities • Local Flood Mitigation Plans • Recognizes all sources of flooding • Expands on flood hazard areas identified in HMP • . Comprehensive Plans • • Local planning initiatives that identify vulnerable areas and protection strategies Direct future development Flood Management Ordinances • • Regulate development in the floodplain Local requirements for flood insurance Nuisance Flood Plans Maryland Department of the Environment . Targeting tidally influenced flood problems (some address urban flooding) 55#56Information Exchange and SWM Planning Integrating Local Knowledge into Stormwater Planning to Promote Climate Resiliency Can Include: • Consider ESD criteria for water quality protection Consider watershed hydrology analyses to support decision framework • Evaluate watersheds for specific quantity management requirements . • Identify capital improvement projects to protect infrastructure and local streams/floodplains Maryland Department of the Environment 56#57Maryland Department of the Environment Why Information Exchange? Existing Local Flood Management Policies and Planning Tools Integrating Local Knowledge into Stormwater Planning Process to Promote Climate Resiliency Broad goal is to enhance and build upon existing local initiatives and develop a flexible framework toward addressing future priorities and needs We Need Your Input 57 57#58https://sb-227-maryland.hub.arcgis.com/pages/information-exchange Advancing Stormwater Resiliency in Maryland Home About Key Components ▾ Resource Library Coming Soon! Explore the map below to learn about local stormwater and flood management programs*: intown Allegheny stains Cumberland Carrot Allegany Staunton Hagerstown Herford Martburg Fredenbenck ains Ridge Mountains Blue Ridge Moun Harrisonburg Montgomery B Wilmington Dover Delaware styland ebo [13] Dale Ci 13 Fredericksburg Duchester Weisbury St. Mary's Charlottesville 462 Esri, USGS Fairfax County, VA, VGIN, Esri, HERE, Garmin, FAO NOAA, USGS, EPA NPS | MD MAP SHA. DOIT Worceste Vineland Powered by Ear *The data sources generated on this webpage are regularly checked for updates by the Maryland Department of the Environment to ensure the most current information possible is provided. However, because this data is provide by sources outside the Department, we are not responsible for and cannot guarantee the completeness or accuracy of the data provided by these sources. a Sign In Maryland Department of the Environment 58#59Take Home Points • Flooding is a problem that will continue with our changing climate Maryland Department of the Environment • • • • Solving Maryland's flooding problems will require a comprehensive effort We need to identify where the flooding problems are occuring Watershed studies are needed to identify the source of the problems and recommend solutions Solutions will need to include: • • Stormwater management and floodplain regulations to address new and redevelopment Conveyance system upgrades and maintenance Flood acquisitions and warning systems Hazard mitigation plans Education and outreach to inform citizens of hazards and improve preparedness Funding is necessary to move Maryland forward to stormwater resiliency 59 59#60Where Do We Go from Here? Spring 2022 Phase I: Information Gathering and Analysis WE WANT TO HEAR FROM YOU: surveys, interviews, data sharing Flooding events in your jurisdiction Stormwater management requirements and watershed studies Data and resource gaps Phase II: Draft Regulations Updates Summer and Fall WHERE DO WE NEED TO GO: use data to update requirements 2022 -Design storm precipitation standards ESD to the MEP design storm Stormwater quantity management criteria Winter and Spring 2023 Phase III: Identify Data and Programmatic Gaps HOW WE CAN HELP: build resources and strategies Education -Tools -Funding opportunities https://sb-227-maryland.hub.arcgis.com Maryland Department of the Environment 60#61April is Maryland's Flood Awareness Month! In 2021, Governor Hogan proclaimed April as Maryland Flood Awareness Month Sponsored by the Maryland Resiliency Partnership https://resiliencypartnership.com/ Target Audience: All Marylanders Theme: Know-Plan-Act #FloodAwareMD Please, get involved! # Maryland Flood Awareness Month Maryland Department of the Environment KNOW PLAN ACT 61#62Questions? Maryland Department of the Environment GIS Technical Advisory Group SWM Technical Advisory Group Watershed Study Technical Advisory Group Stewart Comstock [email protected] 62 62