Potential Water Supply Interconnections to Danbury, CT

Share Print       Smaller Larger

JANUARY 2006
planning bulletin 118

SECTION ONE

prepared By roald haestad, inc.
consulting engineers, waterbury, ct

 

INTRODUCTION

In January of 2005 Danbury presented to HVCEO that City's plan to study the use of Candlewood Lake as a source of water supply. As the nearby towns of Brookfield, New Milford, Sherman and New Fairfield have significant land area within the Candlewood Watershed, Danbury was seeking to establish a mechanism for communication as it proceeds.

It was also agreed early in 2005 that the potential for water main interconnections between Danbury and other communities would be studied. It was agreed that HVCEO would be the sponsor of the interconnection study.

This would be for the purpose of determining if towns are interested in helping to fund the Danbury water supply expansion and then receive some of the water supply newly available. The town by town results are found in the following sections:

• SECTION 2; CONNECT TO CENTRAL BETHEL
• SECTION 3: CONNECT TO NORTHERN BETHEL
• SECTION 4: CONNECT TO SOUTHERN BROOKFIELD
• SECTION 5: DANBURY'S INTERNAL NEEDS
• SECTION 6: CONNECT TO NEW FAIRFIELD
• SECTION 7: CONNECT TO SOUTHERN NEW MILFORD
• SECTION 8: CONNECT TO NEWTOWN
• SECTION 9: CONNECT TO RIDGEFIELD

Study components approved by HVCEO include 1) Collect information and prepare a summary of water supply needs for the towns of Brookfield, Danbury, Ridgefield, Bethel, New Fairfield, Newtown and New Milford; 2) Evaluate the City of Danbury's distribution system and the potential for interconnections with the surrounding towns; and 3) Identify and prepare budget estimates for the costs for pumping stations, pipelines, and operational expenses to serve each town with water from Danbury to meet projected future needs.

It was determined early on that three towns in the planning region, Bridgewater, Redding and Sherman, would not be included in this interconnection study. The reason was the combination of their remoteness from Danbury coupled with lack of need.

It is not the intent of Danbury or HVCEO to spread potentially growth inducing water supplies out from central areas to more outlying locations. Rather, where a town is seeking new sources of supply for properly planned growth, the option of interconnection with Danbury could now be considered as such decisions are made.

In return, Danbury is seeking formal partners in financing the development of Candlewood Lake as a supply source.

Pease note that in the texts above the important term "hydraulic grade line" (HGL) is used frequently. In simple terms, a water system's hydraulic grade line is the elevation to which its water will rise if unrestricted and at which the pressure will be zero. An example would be the overflow elevation of an elevated storage tank.

As an overview for the region, Table 1 below shows the additional water supply needs by town for 2004, 2009, 2020 and 2050 in order to meet projected demands with a 15 percent margin of safety. The projections were taken and or extrapolated from existing water supply plans, except for Brookfield and New Fairfield, where no plans were available.

TABLE 1
SUMMARY OF ADDITIONAL SOURCE OF SUPPLY NEEDS
BY TOWN, IN MILLION GALLONS PER DAY (MGD)