DeKalb Greenridge Community Informative Session Water Presentation

On September 20, 2021 DeKalb County District 7 Commissioner Lorraine Cochran-Johnson facilitated an important conversation to provide an update on the Watershed Management Capital Improvement Plan as it specifically affects the Greenridge Community. This presentation was shared with attendees.

Transcript

1. Department of Watershed Management Update Regarding the Greenridge Community and Water Delivery Challenges Monday September 20, 2021 9/20/2021 1
2. • Overview of the Countywide Water Distribution System • An Aging Water System • Problematic Pipe Types • Greenridge Break History • Project Solutions for the Greenridge Community • Communications Plan 09/07/2021 2 AGENDA
3. Department of Watershed Management Greenridge Water Distribution Solutions Update 09/20/2021 3 Overview of Water Distribution System • By 2030 ~600 miles of water pipe needs replacement due to age, size or material type • Age of pipes can cause risk of breaks or tuberculation • Now prioritizing projects based on a new risk- based approach and hydraulic modeling, ensuring a need and operational efficiency from each project implemented • Non-revenue water losses are at unacceptable levels • 36% of CIP 2021 budget is assigned to address these issues ($864 million) Tuberculation: build-up of calcium that restricts water flow Aging AC pipe is past its service life and prone to breaks.
4. Department of Watershed Management Greenridge Water Distribution Solutions Update 09/20/2021 4 Problematic Pipe Types MATERIAL LENGTH (MILES) BREAKS (% of overall) CHALLENGE PRESTRESSED CONCRETE 7 <1 9x as likely to break as other materials, often catastrophically CEMENT 522 35 High break rate after 50-70 years of service (132 miles already greater than 65 years old) POLYVINYL CHLORIDE 210 12 CAST IRON 820 27 Pipe will tuberculate with age, substantially reducing water flow (e.g. Briarcliff water pressure project) ‣ Miles of water pipe reaching 70 years old: ‣ Now (2020): 215 miles (install date 1950 or earlier) ‣ By 2030: 596 miles (install date 1960 or earlier) ‣ By 2040: 1290 miles (install date 1970 or earlier) ‣ By 2050: 1745 miles (install date 1980 or earlier)
5. Department of Watershed Management Greenridge Water Distribution Solutions Update 09/20/2021 5 Costs of an Aging Water System ‣ Breaks are increasing as the water distribution system ages Water main breaks per year (1986-2018) Breaks by pipe type and size (1986 to 2018)
6. Department of Watershed Management Greenridge Water Distribution Solutions Update 09/20/2021 6 Break History • This area has experienced 15 breaks since 2017 • The area is known to have high pressures caused by system constraints and topography • Cement pipes in the area are known to be problematic • Key pipes installed in 1968 and are undersized. Aging AC pipe is past its service life and prone to breaks.
7. Greenridge Community Phase I of project is currently being designed Aging 1968 era concrete pipe is undersized, a poorly- performing pipe type, and a high-pressure area of the system Project is being developed in two phases as a portion under the rail line will be more complex due to permitting Corrective Actions Greenridge Water Distribution Solutions Update
8. Department of Watershed Management Greenridge Water Distribution Solutions Update 09/20/2021 8 Communications Plan • Project Communications: • Community meeting next year to more fully explain the corrective project phases • Project updates on website and dedicated project email box • Current Response: • DWM is exploring posting notifications of breaks on Next Door • Call system – “We know of a break in this area” message automated