Stormwater Commission

STORMWATER COMMISSION REPORT BOARD OF TRUSTEES PRESENTATION SEPTEMBER 22, 2009 Stormwater Commission Full report available at www.vniles.com Village of Niles, Illinois Presentation Outline • A Record Storm • Stormwater Commission • Analysis and Findings • Recommendations • Ongoing Efforts and Accomplishments • What Now? Photo 1: Sewer Slip Lining Stormwater Commission Village of Niles, Illinois 1  A Record Storm • September 12-14, 2008 – 9.5 inches over a 15-hour period (MWRDGC) – Storm was preceded by ground saturating/river swelling storms – Storm had high intensity, long duration, and soil saturation – Was one of two 100-year storms in past 22 years Graphic 1: Peak Stream Gage Height in the North Branch of the Chicago River Stormwater Commission Village of Niles, Illinois A Record Storm • September 12-14, 2008 – Howard Street and Harts Road flooded – Milwaukee Avenue closure near Maryland Street – Several businesses, schools, TAM Golf Course – 781 homes estimated to have flood damaged Photo 2: Monroe Street Photo 3: Carol Street Combined Sewer Separate Storm Sewer Stormwater Commission Village of Niles, Illinois 2  A Record Storm • Flood Recovery – Flood Hotline/News Releases – Staff toured Village w/ FEMA – Public Meeting – FEMA Stationed in Village Hall – 561 homeowners received FEMA flood assistance totaling $1.15 million or about $2,000 per applicant – Municipal received $85,000 in FEMA flood assistance for property loss and emergency costs – 19,000 yards of flood debris Graphic 2: Flood Recovery Meeting Stormwater Commission Village of Niles, Illinois A Record Storm Local Stormwater System • 150 miles of Combined Sewer (75%) • Common in older municipalities • Conveys stormwater and sanitary • Flows to MWRDGC for treatment in Skokie • During heavy storms, combined sewers overflow into eight Deep Tunnel points Combined Sewer (green) Graphic 3: Village Combined Sewer System Stormwater Commission Village of Niles, Illinois 3  A Record Storm Metropolitan Water Reclamation District of Greater Chicago Graphic 4: Total Precipitation September Future of TARP capacity? – McCook Reservoir • 2015 – Adding 3.5 billion gallons • 2023 – Adding 7 billion gallons Graphic 5: TARP System Stormwater Commission Village of Niles, Illinois A Record Storm Why does it seem that heavy storms occur more often? - 100 year - 5 to 10 year - 2 to 5 year - Special circumstance DailyRainPrecipitationfor ChicagoArea 7 6.49 6.64 F Precipitation (inches) 6 M 5 4.31 4.45 3.58 A 4 3.2 3.4 3 M 3 2.35 1.9 J 2 J 1 A 0 S 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 O Year - 1987 to 2009 Graphic 6: Daily Rain Precipitation for Chicago Area 1987-2009 Stormwater Commission Village of Niles, Illinois 4  A Record Storm Why does it seem heavy storms occur more often? – New development increases stormwater runoff volume Graphic 7: Hydrologic Cycle Graphic 8: Stormwater Runoff Volume – Climate Change in Illinois • Increased temperatures cause more intense storms Stormwater Commission Village of Niles, Illinois Stormwater Commission • Goal of Commission – To identify, evaluate, and report back on “ persistent” stormwater conditions within the Village of Niles • Study Methodology – Collect data (survey, site visits, homeowners) – Plot Data with GIS mapping system – Conduct a Workshop – Identify existing conditions, opportunities, recommendations – Report to Mayor and Village Board Photo 4: Vactor Cleaning Crew Stormwater Commission Village of Niles, Illinois 5  Stormwater Commission • Resident Stormwater Survey Results – 436 responses (estimated 56% to 78% response rate) – Valuable data on the devastation of 2008 flood – Village should increase homeowner stormwater education Are You On Combination Sewer System? 70% 65% Percent of Respondents 60% 50% 40% 30% 17% 18% 20% 10% 0% Yes No Do Not Know Graphic 9: On Combination Sewer? Stormwater Commission Village of Niles, Illinois Stormwater Commission • Resident Stormwater Survey Results – 436 responses (estimated 56% to 78% response rate) – Valuable data on the devastation of 2008 flood – Village should increase homeowner stormwater education Where Sump Pump Discharges 60% 56% Percent of Respondents 50% 40% 30% 23% 20% 20% 10% 1% 0% Yard Sewer Other Do Not Know Graphic 10: Where does your sump pump discharge? Stormwater Commission Village of Niles, Illinois 6  Stormwater Commission We Need To Know More About “ Persistent” Flooding Flooding in 10 Years 30% Percent of Respondents 25% 25% 18% 19% 20% 16% 15% 15% 10% 8% 5% 0% Never 1-Time 2-Times 3-Times 4-Times 5 or More Times Graphic 11: Number of Times Flooded in Ten Years Stormwater Commission Village of Niles, Illinois Stormwater Commission What about “persistent” flooding? Graphic 12: Persistent Flooding Density Map Stormwater Commission Village of Niles, Illinois 7  Stormwater Commission 40 36 What about “persistent” flooding? 35 Number of Homes 30 25 19 20 15 11 10 6 5 3 0 Sewer Backup Seepage Window or Door Sump Pump Recently System Failure Installed Flood Control System Point of Entry Graphic 13: Water in Home 5+ Times in 10 Years – 59 Homes – 5 – water from open land (Cemetery, Park, OLR) – 4 – water from street (Osceola, Oconto, Olcott) – 2 – attached depressed garages Stormwater Commission Village of Niles, Illinois Analysis and Findings • In-home flooding issues – Sewer Surcharge • No flood control • Failed/improperly installed flood control • Sump connected to sewer • Blocked/failed lateral Graphic 14: Typical Niles Home without Flood Control Stormwater Commission Village of Niles, Illinois 8 Analysis and Findings Graphic 15: Typical Home with Overhead Sewer Stormwater Commission Village of Niles, Illinois Analysis and Findings Graphic 16: Check Valve Stormwater Commission Village of Niles, Illinois 9 Analysis and Findings – Seepage in basement through cracks, holes, and joints • Poor or no flood proofing • Downspout or sump discharge too close to foundation • No sump pump or undersized • Lot grading • Failed drain tile Graphic 17: Basement Seepage Stormwater Commission Village of Niles, Illinois Analysis and Findings – Stormwater entering through window wells, stairwell doors, garage doors and crawl space vents • Flooded streets, vehicle wakes and below ground garages • Downspout and sump pump discharge to close to foundation • Poor lot grading Photo 5: Crawl Space Vent Photo 6: Flooded Window Well Stormwater Commission Village of Niles, Illinois 10 Analysis and Findings – Sump pump fails • Switch failure • Check valve failure • Power outage • Absence of battery backup • Inadequate maintenance • Insufficient capacity Graphic 18: Sump Pump System Stormwater Commission Village of Niles, Illinois Analysis and Findings – Inflow and Infiltration (I/I) • Inflow: direct flow of stormwater into the sewer system • Infiltration: indirect flow of stormwater into sewer system • Goal must be to reduce or eliminate all inflow and infiltration to help reduce peak flow and maintain sewer capacity Photo 7: Downspout Inflow Photo 8: Home Lateral Infiltration Stormwater Commission Village of Niles, Illinois 11  Analysis and Findings • General Stormwater issues – Street Flooding • Breached flood control systems, vehicle damage, limited homeowner/ emergency access, barricades not available – Alley Flooding • Limited access, flooded garages, flooded yards Photo 10: Flooded Alley Photo 9: Flooded Streets and Yards on Olcott (Blocked Inlet Restrictor) Stormwater Commission Village of Niles, Illinois Analysis and Findings – Rear Yard Flooding • Most times caused by obstruction of natural flow due to a fence, garden, or other landscaping not approved by Engineering • Neighbors downspout/sump pump discharge • New construction adjacent to property • Charged and overflowing rear yard drain without a check valve Photo 11: Flooded Rear Yard on Maryland Photo 12: Flooded Rear Yard on Greenleaf Stormwater Commission Village of Niles, Illinois 12 Analysis and Findings – Stormwater Runoff (large open space) • A 2.1” rain generates 50,000 gallons of stormwater per acre • Cemeteries, parks, open lands • Runoff contributes to combined sewer system charging • Runoff contributes to flooding of roads and adjacent properties Photo 13: Park Land Runoff Photo 14: Cemetery Runoff on Main Stormwater Commission Village of Niles, Illinois Analysis and Findings – Consider Green Infrastructure/Streets Option • Divert, capture and slowdown stormwater before it enters system • Reduces peak flows that cause backups • Increase stormwater capacity • Reduce need for expensive hard infrastructure • Palatine and Glenview Rain Garden program & MWRD Rain Barrel Photo 15: Rain Garden Photo 16: Bioretention on Side Street Stormwater Commission Village of Niles, Illinois 13  Analysis and Findings – Consider Green Infrastructure/Streets Option • Permeable pavement is used in Chicago and Des Plaines • Permeable pavement in alleys & side street parking lanes • Bioretention in large parking lots instead of raised islands • Federal stimulus priority & IEPA requirement Graphic 19: Permeable Pavement Photo 17: Bioretention In P-Lot Stormwater Commission Village of Niles, Illinois Analysis and Findings – Homeowner Education • 65% did not know if they were on combined sewer system • Many are not comfortable with their home storm/sanitary system • Many more do not understand MWRD and TARP Graphic 20: Education Material Developed for Workshop Stormwater Commission Village of Niles, Illinois 14  Analysis and Findings – Geographic Information Systems (GIS) • What do we have? • What do we need? • Where do we want to go? Graphic 21: Stormwater Mapping Progression for Analysis Stormwater Commission Village of Niles, Illinois Analysis and Findings – Regional System vs. Local System Niles Graphic 22: Map of Locks and Lock Operation During Floods Stormwater Commission Village of Niles, Illinois 15  Analysis and Findings – Sewer Capacity Enhancements • Commission has • identified the types of stormwater issues • identified where stormwater issues are most persistent • begun working to correct what is practical • Commission must now • turn to an engineering firm for engineered solutions and a recommended capital improvements program Photo 18: Monroe Front Door Photo 19: Sewer Improvement Photo 20: New Sewer Stormwater Commission Village of Niles, Illinois Recommendations – Stormwater Education 1. Flood Protection Starts at Home Campaign 2. Encourage Sump Pump Maintenance and Battery Backup 3. Stop Inflow & Infiltration Into Combined Sewer Systems 4. Reduce Stormwater Runoff (large and small) 5. Awareness of Natural Flow of Stormwater 6. Stormwater Contamination Stormwater Commission Village of Niles, Illinois 16 Recommendations – Village Operations 1. Continue with GIS System Mapping 2. Continue Sewer Rodding Program 3. Continue Aggressive Sewer Inspection and Maintenance 4. Engage MWRDGC and Encourage Participation Photo 21: Basin Repair Photo 22: Sewer Televising Stormwater Commission Village of Niles, Illinois Recommendations – Village Policy 9 Overhead Sewers, Lot Grading Verification/Alterations • Enforcement of Ordinance Eliminating Inflow • Plan Commission to review Permeable Surface Ord. 1. Adopt Stormwater Management for Developments 2. Adopt Fee Schedule for Inspection & Connection 3. * Adopt Sump Pump Discharge Amendment/Enforcement 4. * Adopt Prohibition of Below Grade Attached Garages 5. * Adopt Fence Regulation Amendment 6. * Adopt Amendment Prohibiting Outdated Sanitary Service * On September Board Agenda for Consideration Stormwater Commission Village of Niles, Illinois 17  Recommendations – Village Capital Programs 1. Continue Slip-Lining Program 2. Incorporate Green Infrastructure Concepts 3. Investigate Possible Acquisition Projects through FEMA 4. Consider a Part-Time Stormwater Specialist 5. * Approve Commission to Begin Interviewing Stormwater Engineering Firms * On September Board Agenda for Consideration Stormwater Commission Village of Niles, Illinois Ongoing Efforts and Accomplishments • Stormwater Workshop • Educational material • Many small wins for individual homeowners • Glenview to the north • Cook County and Greenwood Avenue • Our Lady of Ransom and Park Ridge Park District • Maryhill Cemetery/Saint Adalbert Cemetery • Niles Park District • Stormwater Commission Report Stormwater Commission Village of Niles, Illinois 18  – What now? 1. Board considers amendments 2. Return with October amendments 3. Establish homeowner education program 4. Continue working with homeowners 5. Continue working with 3rd party property owners 6. Return with recommendation for engineering firm & scope of work 7. Pursue grant funding for a capital improvement plan Stormwater Commission Full report available at www.vniles.com Village of Niles, Illinois Stormwater Commission Full report available at www.vniles.com Village of Niles, Illinois 19