Memorandum

 

TO:

David L. Corliss, City Manager

FROM:

Mike Lawless, Interim Asst. Director of Utilities

CC:

Cynthia Boecker, Assistant City Manager

Dave Wagner, Director of Utilities

Philip Ciesielski, Assistant Director of Utilities

DATE:

July 1, 2008

RE:

CIP Water Projects Recommendation

 

 

The 2009 CIP for the Utilities Department includes two significant water system improvement projects, the Kaw WTP Raw Water Intake and Phase I construction of the Kaw WTP Water Transmission Main to the southeast area of the City. The projects are $6.6 million and $6.0 million respectively. Both projects are needed to provide a reliable, safe and redundant water supply system for the City. The Utilities Department would recommend that both projects be included in the 2009 5- year CIP and Rate Model plans.

 

Kaw WTP Raw Water Intake – The Kaw Water Treatment Plant treats water from the Kansas River to supply potable water to the City. The point of diversion (intake) is through a structure called a crib and is located in the river about 60 feet from the riverbank. There are currently three cribs in the river but only one is functional. This project would provide a second redundant intake from the river to supply the Kaw WTP. The history, as best can be pieced together, of the diversion points for the Kaw Plant is as follows

 

1.      1886 – A wooden crib was constructed. It was destroyed in or around 1927.

2.      1927 – A concrete crib was constructed to replace the wooden crib. This is one of the three cribs visible in the river. This structure is no longer in service due to the washout of the piping.

3.      1954 – A steel crib was constructed. It is unclear if this was constructed as a redundant intake structure or to replace the loss of the 1927 structure. This is also visible in the river. This structure is no longer in service due to the washout of the piping.

4.      1974 – The currently active crib was constructed in response to the loss of the 1954 structure and is visible in the river.

 

The average service life of the failed cribs was 29.3 years with the longest being in service for 41 years. The current structure is 34 years old. In the event of a failure of this crib or its piping, the Kaw Water Treatment Plant’s capacity would be limited to the amount of raw water received out of the existing well field and temporary intake pumps placed in the river. While the Clinton Water Treatment Plant’s expansion is nearing completion and will result in a capacity of up to 25 million gallons per day, it does not have the capacity to provide treated water for the entire city, and wholesale customers during peak summer demands.

 

Kaw WTP Water Transmission Main – This design of Phase I and property acquisition for all three phases of this project were authorized in 2007 and are underway. The project will construct a new water transmission main from the Kaw WTP east under the Kansas River to North Lawrence, east through North Lawrence and then south under the Kansas River to the southeast area of the City at approximately 23rd and O’Connell. The project is divided into three phases with a total length of 31,000 feet of 30” and 36” diameter pipe.

 

The first phase of the project will complete one river crossing and connect into the existing water distribution system in North Lawrence. This phase will immediately provide North Lawrence with a redundant water supply. At the present time there is a single 1977 20” water main on the southbound Kansas River Bridge to supply water to North Lawrence.

 

The completion of all three phases of the project provide adequate water supply for the development of the Farmland Property, and the continued development of the East Hills Business Park and Southeast Lawrence area. The completion of all three phases, to 23rd & O’Connell, also provides a starting point for future projects to supply water to the Wakarusa WRF, and additional capacity to serve Baldwin City and Rural Water District No. 4. Without the completion of this project the existing water supply infrastructure does not have the capacity to fully develop the areas noted.

 

The Department of Utilities recognizes the critical nature of both of these projects to the continued provision of safe and reliable water and recommends proceeding with each in the 2009 5-year CIP and Rate Model plans.