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Public Information Meeting Parkway Drive/17 th Avenue Rehabilitation. Rawson Avenue to Hemlock Court. Project Area: Parkway Dr / 17 th Ave (from Rawson to Hemlock). Parkway Drive/17 th Avenue Rehabilitation (Rawson to Hemlock). Purpose of Meeting:
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Public Information MeetingParkway Drive/17th Avenue Rehabilitation Rawson Avenue to Hemlock Court
Project Area: Parkway Dr / 17th Ave (from Rawson to Hemlock)
Parkway Drive/17th Avenue Rehabilitation (Rawson to Hemlock) • Purpose of Meeting: - Summarize storm events & existing systems - Summarize proposed work - Answer questions and address comments
Significant Storm Events (Recent History): - June 1997 (2% annual chance flood) - August 1998 ( 10th highest single day rainfall – MKE) - July 2000 (rated at 1% probability) - June 2008 (Est. 0.2 to 1% probability) - July 2010 ( Est. 0.2% probability) - Oak Creek gaging station – 47 year record- June 2008 - June 2008 flow was only exceeded once – July 2010 - South Milwaukee not isolated case – Widespread flooding in 2008 and 2010
System Assessments - Oak Creek Watercourse/Floodplain functioned to protect loss of life, loss of structures, limited the amount of property damage (public & private) - Storm water collection system - Pipe & inlet design capacity exceeded - Inlet clogging (debris), major & minor collection systems full - Private systems exceeded (sump crocks, yard drainage)
Continued - Sanitary Sewer System - Subject to infiltration & inflow (I/I) of clear water - Results in surcharging of system which leads to basement back-ups - Separate Storm & Sanitary Systems – I/I sources - Public system – not a sealed system - Pipe joints or cracks - Manholes - Old connections - Private systems - Illegal drain connections (Roof, Driveway) - Foundation drains – homes without sump pumps (1920 – 1954) - Private laterals ( house to main) - Sump pumps into floor drains or wash tubs - Sump pump excess / high ground water
Methods & Options to reduce I&I - Public system - Manhole seals / sealed lids - Manhole replacement / lining - Pipe lining / pipe replacement - Video inspection to identify repairs - Drainage improvements – keep ponded water off street & private property - Provide sump connections - Private system - Replace old laterals - Eliminate illegal connections - Eliminate foundation drains to sanitary
Most Effective Solutions to reduce chance of sanitary backups & flooding- Parkway Heights Area: - Sanitary System - Has capacity for standard design flows - Reduce MH hydraulic losses (90º bends) - Replace or reconstruct manholes - Sanitary sewer replacement/repair where inflow (cracks) - Improve efficiency of relief (By pass) station - Reduce flow from south (possible improvements by Missouri Lift Station)
Continued - Storm Sewer- undersized based on existing development, runoff - Construct relief storm sewer & inlets - Construct secondary overland flow path to creek - Replace old inlets (improving upstream collection) - Provide sump connections if feasible - Provide upstream storm sewer work where basement flooding causing sanitary inflow - Street capacity – reduce crown for increased capacity
Contemplated Work - Sanitary Sewer: - Sanitary manhole repair or replacement - Possible replacement of sanitary main at Spruce (minor cracks) - Other minor work at Hemlock & Spruce to improve hydraulics - Install 12” sanitary pipe for future relief station upgrade (3 – 4 months design following approval, $200 – $250,000 funding required) - Possible modifications near Missouri Lift Station
Contemplated Work Continued Storm Sewer: - Install relief line between 521 & 531 Parkway Drive - Install overland bypass and storm sewer work on 17th Avenue south of Oak - Other storm work (inlets) Watermain: - Hemlock main replacement ( Parkway to Poplar) - Other valve replacement Street Rehabilitation: - Spot replacement of curb & gutter - Grade to remove high crown in critical areas - Remove and replace asphalt paving
Preliminary Schedule: - August contract awarded - Sanitary, Storm and Watermain construction – September/ October 2011 - Curb work / base Asphalt – October/ November 2011 - Surface Asphalt – Spring 2012 - Relief (bypass) Station upgrade – TBD based on funding
Summary - City Goal: - Reduce risk of floods and sanitary back-ups by design & construction of cost effective / practical solutions - Property Owners: - Do what you can to protect property and others - Downspouts, grading, drainage, backflow valve, sump pump capacity - Discharge of sumps