Landbase Systems Draft 5/2/2014 Page: 1

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1 Study of the potential Green Stormwater Infrastructure (GSI) strategies and options to reduce localized flooding and combined sewer overflows in conjunction with combined network adjustments along and upstream of Rosedale Street Landbase Systems Draft 5/2/2014 Page: 1

2 1 Area where 27+ annual million gallons of potential High-Yield GSI installations have been defined by Landbase Systems Both ALCOSAN 2003 SWMM model runoff results and GOALprocess runoff simulations estimate there is more than 100 million gallons of annual runoff within the highlighted area above. Within the highlighted area, Landbase Systems has identified possible locations where green stormwater techniques could be used to intercept more than 27 million gallons of annual runoff before that runoff enters the combined network. Landbase Systems Draft 5/2/2014 Page: 2

3 2 Combined Stormwater Drainage Area North of Overflow 1071-OF at the Southern end of Rosedale Street at the Busway Parking area This study focuses within the drainage area of the stormwater inlets connected to the purple highlighted pipe network in the above graphic. The purple highlighted pipe in the above graphic represent the known combined storm and sewer network with the yellow/orange inlet points collecting surface water runoff. This highlighted pipe network drains in two directions: Sewer and stormwater northwest towards the Allegheny River via the combined sewer network and Washington Blvd, or Overflow sewerage southwest to Nine Mile Run via the labeled outfall structure 1071-OF and 1.55 miles of 96 pipe Some goals of this study are to use the most current pipe network models, surface drainage simulations, advanced databases, and optimized field observation techniques to: Identify what Green Storm Infrastructure strategies are most effective and affordable, What balance of green stormwater infrastructure runoff reduction volume in combination with combined sewer network adjustments are necessary to sustainably reduce or eliminate 26+ million gallons of estimated annual sewer overflows to Nine Mile Run via the 1071-OF outfall structure. Collaborate with PWSA engineering team to determine if a balance of green stormwater infrastructure in conjunction with combined network adjustments is more effective, affordable, sustainable, and/or beneficial to the overall community and system life cycle then proposed 100% gray infrastructure solutions. Landbase Systems Draft 5/2/2014 Page: 3

4 3 Primary Combined Stormwater Network Green Stormwater Infrastructure (GSI) Strategies Within combined stormwater networks, focusing on the physical features and behavior of water in three dimensional space and time, we think there are effectively 3 primary of GSI strategies: Infiltrate ONLY GSI: Intercept, Attenuate, Infiltrate, and Overflow Excess water back to the original drainage path. RETURN GSI: Intercept, Attenuate, Infiltrate, Overflow Excess, and RETURN non-infiltrated water to the combined network via drainage pipe where the pre-treated GSI water becomes polluted by sewerage and requires wastewater treatment. REMOVE GSI: Intercept, Attenuate, Infiltrate, Overflow Excess, and REMOVE non-infiltrated water via a separate low flow pipe to convey pre-treated GSI outflow away from the combined network and into the natural water cycle. Landbase Systems Draft 5/2/2014 Page: 4

5 4 Estimated performance summary of the initial three installation sites by type of GSI Strategy Below is a map overview with legend and table summary of estimated annual gallon performance for the proposed initial three Green Stormwater Infrastructure (GSI) sites. The table below and the following pages summarize the differences between 3 possible GSI strategies (Option A: Classic Infiltration Only, Option B phase1: Return Excess Water to the Combined Wastewater Network, and Option C phase 2: Remove Excess Water from the Combined Wastewater Network) Landbase Systems Draft 5/2/2014 Page: 5

6 5 Overview of Green Stormwater Infrastrcuture (GSI) Charts and Tables on Site Layout Pages The bottom portion of each Preliminary Site Layout page contains a GSI performance chart and table estimating the 2003 typical year annual performance of each proposed installation. The graphic below provide a brief description of chart and table contents. Landbase Systems Draft 5/2/2014 Page: 6

7 7 Preliminary Site Layout 1a: Site specific view: Batavia+Oakwood RoadEdge Site NOTE: Preliminary performance statistics for the two proposed installation options on site 1a. Interception rates still need to be optimized. Landbase Systems Draft 5/2/2014 Page: 7

8 8 Preliminary Site Layout 1b: Batavia+Oakwood Road Edge & Ingraham Sites NOTE: Preliminary performance statistics for the two proposed installation options on site 1b. Interception rates still need to be optimized. Landbase Systems Draft 5/2/2014 Page: 8

9 9 Preliminary Site Layout 2: Bennett+Tokay School Site NOTE: Preliminary performance statistics for the two proposed installation options on site 2. Interception rates still need to be optimized. Landbase Systems Draft 5/2/2014 Page: 9

10 10 Preliminary Site 3 Layout: Frankstown+Wheeler Matrin Media Site NOTE: Preliminary performance statistics for the two proposed installation options on site 3. Interception rates still need to be optimized. Landbase Systems Draft 5/2/2014 Page: 10