Program Delivery Plan

SECTION 2
Planning Description
2.1 Planning Overview
This section describes the process used to define the projects outlined in this report. This
planning was necessary to meet the goals of the C-P for a sewer system rehabilitation and
replacement program for SSO reduction.
2.2 Comprehensive Rehabilitation Planning
Rainfall dependent infiltration/inflow (RDII) is the major cause of wet weather related
capacity deficiencies. Previously conducted concurrent monitoring of flow and rainfall
throughout the wastewater collection system during several rainfall events of different
magnitudes was used to characterize RDII and predict the system’s wet weather response to
rainfall.
The collected data were then used to set up and calibrate a computational BTRSSO
hydraulic model of the Baton Rouge collection and transmission system. Each subcatchment
or drainage area was evaluated to establish the share of the rainfall that is
predicted to enter the sewer system. Sub-catchments in which the RDII was excessive are
scheduled for rehabilitation.
The sub-catchments selected for comprehensive rehabilitation were then arranged into 30
projects. Sections 3, 4, and 5 of this report describe the comprehensive rehabilitation
projects.
The sub-catchments selected for rehabilitation will undergo a review of the rehabilitation
work already completed by the DPW. Portions of the sub-catchments that have been
previously rehabilitated will be deleted from the individual rehabilitation projects.
2.3 Capacity Improvement Planning
Capacity improvement planning for the Program is based on evaluating and replacing those
facilities in the collection system where the Program hydraulic modeling and field
information indicate that the existing collection or transmission system is inadequate to
handle the future peak wet weather flows appropriately.
For this analysis, the C-P was divided into ten hydraulically independent basins in order to
separate the collection and transmission systems for analysis. The Program Manager (PM)
developed a process for evaluating the hydraulic model and analyzing its output. The PM
utilized planning and design criteria as a basis for the process overview.
The PM prepared and used a 12-step hydraulic basin analysis method throughout the
planning process. The 12-step process included the following components:
1. Dynamic model runs for evaluation of the capacity of existing pipes with predicted postrehabilitation
flows
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