Briefing on: Draft Report & Recommendations Briefing for: Mayor’s Task Force on the Prevention of Flooding in Bloomingdale and LeDroit Park December 6, 2012 1 1
Agenda Task Force Report Overview Section 1 - Introduction • Section 2 – Existing Conditions • Section 3 – Analysis of 2012 Flood Events • Section 4 – Methodology for Mitigation Strategies • Section 5 – Alternatives to Address Flooding • Section 6 – Regulatory • Section 7 – Storm Preparedness and Response • Section 8 – Project Financing • Section 9 – Recommended Plan • Recommendations Engineering Measures • Regulatory • Code Changes • Operations & Maintenance • Public Outreach • 2 2
Section 2 - Existing Conditions Drainage Area Boundaries Sewer System Description Historical Development of Sewershed Bloomingdale Prior Studies Drainage Area 800 +/- acres 7 studies from 1955-2006 • LeDroit Park Future Development Projects Drainage Area 400 +/- acres McMillan & AFRH in Bloomingdale Drainage • Area Bloomingdale Others proposed in Northeast Boundary LeDroit • Park Drainage Area 3 3
Section 3 - Analysis of 2012 Flood Events Rainfall Conditions NOAA Point Precipitation Sewer System Operation Date Duration Rainfall Frequency Impacts to Properties (Nearly) 7/10/2012 1-hour 1.96” 10 year storm Storm Response 7/18/2012 30-minute 1.35” 5 year storm Cause of Flooding 7/19/2012 15-min 0.94” 5 year storm • Sewer Capacity Exceeded 9/2/2012 2-hour 2.78” 10 year storm • Inadequate Inlet Capacity • Other Possible Causes Investigated (not linked) 4 4
Section 5 - Alternatives to Address Flooding Engineering Alternatives Evaluated: Medium Term Long Term Storage at McMillan Site • DC Clean Rivers First Street Tunnel • McMillan Storage and Flagler Place • Short Term Pump Station Backwater Valves • McMillan Storage and First Street • Engineering Consultations Tunnel • Conveyance to Tiber Creek Removable Barriers • • Rain Barrels – Upstream Installation • Rain Barrels • Green Infrastructure Expansion • Green Infrastructure • Catch Basin Inlet Restrictors • Catch Basins • Inflatable Flood Walls • Detention Vaults • 5 5
Section 6 - Regulatory Overview Backwater Valves Basement Conversions FEMA Insurance Options Legislative Proposals to Address Flooding Historic Preservation Guidelines Water and Sewer Availability Permitting Process 6 6
Section 7 - Storm Preparation and Response Citizen Storm/Flood Preparedness Flood Protection & Homeowner Toolkit Community Outreach & Communication Agency Coordination of Storm Response Voluntary Home Inspections for Environmental & Health Hazard Managing Stress During Emergency Situations 7 7
Long Term Recommendations for Bloomingdale & LeDroit Park: Schedule & Budget Benefits 2025 completion in accordance with Consent Decree 2022 accelerated completion date is possible with District’s assistance DC Government assistance to include: City Administrator appoints champion Task Force • Empowered to direct agencies • Dedicated District agency staff co-located with project team • Eminent domain Permanent property acquisition Easements Expedited permit review Allow necessary street closures, work hours, etc. for construction operations Waive permit fees Funding assistance from DC Government Support Federal funding requests to limit rate increases Total estimated budget = $500-$600M 8 8
Northeast First St Tunnel Boundary Tunnel Long Term Recommendations Improved Bloomingdale Alignment for Bloomingdale & LeDroit Park & LeDroit Park Old alignment Northeast Boundary Tunnel was Facilities planned to meet Consent Decree in planning deadlines New alignment selected to reduce risk and allow more certain Facilities in delivery of flood relief to procurement, design and construction Bloomingdale & LeDroit Park Consent Decree schedule: • Facilities south of RFK - 2018 • Facilities north of RFK - 2025 9 9 9
Medium Term N Recommendations McMillan Stormwater Michigan Ave Storage for Bloomingdale & 6 mg Stormwater LeDroit Park Storage (3 mg from N. Final Site for First Street Cap, 3 mg from First St) Storage and Tunnel Shaft Site being coordinated with District. Four 3 of 10 acres is needed recommendations: for construction 1. McMillan Storm First Street Tunnel • 19’ Dia tunnel, 2,800 ft Water Storage long, 6 mg storage Bryant St 2. First St Tunnel Adams St 3. Rain Barrel Program W St 4. Green Infrastructure V St N. Cap St Temp. 1 st St Pumping Station U St Future 23’ Dia. Thomas St Northeast Boundary Tunnel (Long Term recommendation) 10 10
Medium Term Recommendations for Bloomingdale & LeDroit Park: Scope, Schedule & Budget McMillan Storm Water Rain Barrel District Green Item Storage 1 First Street Tunnel 1 Program Infrastructure • 6 ± mg storage of • 6 ± mg total storage of CSO • Extend • District to invest Scope • Need 3 ac for construction, stormwater program to $10 M in green • 3 mg from N. Cap. 1/3 ac for permanent facilities entire infrastructure in • Temporary pumping station at Storm sewer drainage area Bloomingdale / • 3 mg from 1 st St. storm 1 st & Rhode Island – demolish with 80% LeDroit park in sewer and connect to Northeast rebate public space • leverage existing Boundary Tunnel when it’s (increase of completed 1,000 barrels/ DDOE green roof cisterns) program Temporary or Temporary - until Permanent Temp. program Permanent Permanent? Northeast Boundary / Permanent Tunnel in service infrastructure In service by spring 2014 1 In service by spring 2016 1 Schedule Next 3 yrs Next 5 yrs Cost $12 M $132 M $0.3M $10 M Administrative DC Water DC Water DDOE DDOT / DDOE responsibility Fiscal TBD TBD TBD TBD responsibility Note: 1. Schedule contingent on District assistance as described on previous slide 11 11
Short Term Recommendations for Bloomingdale & LeDroit Park: Scope, Schedule & Budget Rain Barrel District Green Item Backwater Valve Program Removable Barrier Program Program Infrastructure • Strongly recommended • Provide free engineering • Program in • Program in place Scope for approx. 200 homes consultations place includes includes rain • Up to $3,000 rebate for with reported backups in funding for gardens and summer 2012; up to improvements approximately pervious paving $5,000 rebate 250 rain near Rhode • Refine voluntary eligibility barrels; Island Avenue & area; fund BV installation homeowner First Street, NW for approx. 1,000 homes; copay is up to $5,000 rebate waived Temporary or Temporary - until Temporary - until Northeast Temporary – Permanent Permanent? Northeast Boundary Boundary Tunnel in service until $250k Tunnel in service funding is exhausted Schedule Implement until Northeast Next 3 years <6 months <6 months Boundary Tunnel in service Cost Up to $6 M $.375 M $0.250 M $1.1 M Administrative DCRA / DGS DCRA / DGS DDOE DDOT responsibility Fiscal TBD TBD DC Water DC Water responsibility 12 12
Predicted Performance of Recommended Plan Street Ponding Depth Water Level in Sewers Mitigates Mitigates Design Storm RI Ave Bet Flagler U St & RI Ave & Flagler U St & Surface Sewer st St st St Condition (6-hrs) Major Components Schedule 1 st & 2 nd & V St 1 st St 1 & V St 1 Flooding? Backups? Existing 5-year Existing Conditions Predicted average ponding Basement backups No No Conditions (2.8”) depth up to 22” deep predicted • Backwater Valve and Short Term 5-year 2013 Yes, for Yes, for Floodproofing Program Improvements (2.8”) 2013 Some improvement, Some improvement, properties properties • Rain Barrel Program 2013 difficult to quantify difficult to quantify with flood- with • Green Infrastructure Program proofing Backwater Valves • 6 million gallons storm water Medium Term 5-year 2014 <2” <2” <2” Mostly contained within Yes Yes storage at McMillan sand Filter Improvements (2.8”) sewer for 5 year storm Site • First Street NW Tunnel 2016 • Rain Barrel Program 2016 • Green Infrastructure Program 2018 Long Term 5-year Minimal Contained within sewers Yes Yes Improvements (2.8”) • Northeast Boundary Tunnel 2022 15-year <2” Contained within sewers Yes Yes (3.7”) 13 13
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