Public Meeting April 2, 2015 Albany Park Stormwater Diversion Tunnel

Albany Park Stormwater Diversion Tunnel NBCR = North Branch of Chicago River NSC = North Shore Channel Albany Avenue Stream Gauge on NBCR exceeded flood stage: September 2008* July 2010 April 2013* *Significant Flooding Events Introduction - Flooding Albany Park Stormwater Diversion Tunnel

Introduction – 1% Annual Chance Flood Event Albany Park Stormwater Diversion Tunnel Source of Flood Boundary: Detailed Watershed Plan (January 2011) Note: 336 structures impacted in Albany Park neighborhood

Albany Park Stormwater Diversion Tunnel Introduction Flood Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Introduction – Overbank Flooding in Albany Park Neighborhood Albany Park Stormwater Diversion Tunnel The purpose of this project is to alleviate overbank flooding along the NBCR in the Albany Park neighborhood.

Albany Park Stormwater Diversion Tunnel Alternatives Considered Albany Park Stormwater Diversion Tunnel Alternatives Considered But Dismissed Remove North Branch Dam Modify Ridgeway Bridge (Eugene Field Park) Add Upstream Storage Alternatives Analyzed Floodwall (DWP) Buyouts Floodproofing Structures Diversion Tunnel

Albany Park Stormwater Diversion Tunnel Introduction - Flooding Alternatives Considered – Floodwall or Buyouts Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Plan View Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Profile View Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Inlet Plan View Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Inlet Cross Section View Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Inlet 3-D Model (no water) Albany Park Stormwater Diversion Tunnel NBCR Flow Direction

Albany Park Stormwater Diversion Tunnel Introduction - Flooding Proposed Project – Inlet 3-D Model (1% Annual Chance Flood) Albany Park Stormwater Diversion Tunnel To Dam To Diversion Tunnel *Roughly 45/55% Split Between River and Diversion Tunnel for the 1% Annual Chance Flood NBCR Flow Direction

Albany Park Stormwater Diversion Tunnel Introduction - Flooding Proposed Project – Outlet Plan View Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Outlet Cross Section View Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Outlet 3-D Model (no water) Albany Park Stormwater Diversion Tunnel NSC Flow Direction

Albany Park Stormwater Diversion Tunnel Introduction - Flooding Proposed Project – Outlet 3-D Model (1% Annual Chance Flood) Albany Park Stormwater Diversion Tunnel NSC Flow Direction From Diversion Tunnel

Albany Park Stormwater Diversion Tunnel Introduction - Flooding Proposed Project – Hydraulic Profile of NBCR Upstream of Dam (1% Annual Chance Flood) Albany Park Stormwater Diversion Tunnel

Introduction - Flooding Proposed Project – Hydraulic Profile of NBCR and NSC Below Dam (1% Annual Chance Flood) Albany Park Stormwater Diversion Tunnel

Construction – General Sequence Part 2 (Tunnel Construction) Albany Park Stormwater Diversion Tunnel