WA0501-CS050607 Ken Griffin - Coppell Water Analysis
From: "Angela Lang" <ALang @BHCLLP.COM>
To: <kgriffin @ci.coppell.tx.
Date: 6/7/2005 4:57 PM
Subject: Coppell Water Analysis
CC: "Doug Showers" <DShowers @BHCLLP.COM>
Mr. Griffin:
We have analyzed the water system with the new development southeast of Bethel School Road and Denton Tap Road. The
23 homes will impact the system with a Toad of 0.028 MGD at max day and 0.0596 MGD at max hour.
With the assumption of 1500 gpm (2.16 MGD) required at two fire hydrants (750 gpm each) at any given time, the results for
flows and pressures are as follows:
At Max Day without Proposed 8" WL connected to Meadowcreek WL:
1. In the new neighborhood some fire flows are low in the range of 1.53 -1.59 MGD.
2. Some Residual Pressure in the new development are in the range of 32 -35 psi.
3. Minimum Zone Pressure in the system is 35 psi in the new neighborhood.
At Max Day with Proposed 8" WL connected to Meadowcreek WL:
1. Fire flows to the new development are in the range of 2.16 - 2.23 MGD; a 41% increase of flow
2. Residual Pressures in the new development are in the range of 55 -74 psi; a 69% increase of pressure
3. Minimum Zone Pressure in the system is approximately 48 psi at a dead end water line along Bethel Rd west of Royal Ln.
At Max Hour without Proposed 8" WL connected to Meadowcreek WL:
1. In the new neighborhood some fire flows are low in the range of 1.55 -1.61 MGD.
2. Some Residual Pressure in the new development are in the range of 32 -35 psi.
3. Minimum Zone Pressure in the system is 35 psi in the new neighborhood.
At Max Hour with Proposed 8" WL connected to Meadowcreek WL:
1. Fire flows to the new development are in the range of 2.16 - 2.32 MGD; a 35% increase of flow
2. Residual Pressure in the new development are in the range of 50 -69 psi; a 53% increase of pressure
3. Minimum Zone pressure in the system is approximately 46 psi at a dead end water line along Bethel Rd west of Royal Ln.
*Although TCEQ's minimum requirement is 35 psi, it is our experience that at pressures lower than 40 psi, there are larger
amount of complaints about the lower water pressure.
We are available at your convenience to discuss this analysis further.
Sincerely,
Angela Lang, E.I.T.
Birkhoff, Hendricks, & Conway, L.L.P.
7502 Greenville Ave., #220
Dallas, TX 75231
(214) 361 -7900 phone
(214) 361 -0204 fax
alang@bhcllp.com
Ken Griffin - Coppell 2005125 Water Model Option
From: "Angela Lang" <ALang @BHCLLP.COM>
To: <kgriffin @ci.coppell.tx.us>
Date: 6/7/2005 10:58 AM
Subject: Coppell 2005125 Water Model Option
CC: "Doug Showers" <DShowers @BHCLLP.COM>
Mr. Griffin:
We have evaluated the impact of the new development on the water system as you have requested. The fire flow
available to the new neighborhood is adequate for a 1000 gpm flow at a fire hydrant. This fire flow is also the same with or
without the proposed 8 -inch water line connected to Meadowcreek water line. As for pressures in the neighborhood and across
the system, the following are our results:
With Proposed 8 -inch WL connected to Meadowcreek WL:
1. The residual pressure in the neighborhood is in the range of 62 -74 psi.
2. The minimum zone pressure is 48 psi at the deadend 16 -inch WL along Bethel Rd west of Royal Ln.
Without Proposed 8 -inch WL connected to Meadowcreek WL:
1. The residual pressure in the neighborhood drops approximately 40% to 38 psi (still above TCEQ minimum pressure of 20
psi).
2. The minimum zone pressure is in the range of 38 -41 psi (still above TCEQ minimum pressure of 35 psi) at the interior 8 -inch
loop around the new neighborhood.
From our analysis, the existing 6 -inch and 8 -inch lines that will be serving the new development are sufficient for daily
demands and fire flow.
We are available at your convenience to discuss this analysis further.
Sincerely,
Angela Lang, E.I.T.
Birkhoff, Hendricks, & Conway, L.L.P.
7502 Greenville Ave., #220
Dallas, TX 75231
(214) 361 -7900 phone
(214) 361 -0204 fax
alang@bhcllp.com