For approach water mains constructed under a developer-initiated or city-initiated approach water main project, the water main capacity charge shall be calculated as follows.
(a) Development cost shall be determined consistent with the definitions contained in § 35-88.
(b) For a developer-initiated approach water main, the developer is responsible for providing all information, studies and exhibits that may be reasonably requested by the city. For a city-initiated approach water main, the city’s consultant engineer shall provide any necessary exhibits as requested by the city.
(c) For a developer-initiated approach water main that the city has cost participated to over-size the approach water main, the city shall be responsible for providing calculated basin area, together with any necessary exhibits on water mains that have city cost participation for over-sizing the developer-initiated approach water main.
(d) For a developer-initiated frontage water main that the city has cost participated to oversize, the water main capacity charge calculation shall be based on the delta MGD capacity of over-sizing the developer-initiated approach water main.
(e) Developer maybe eligible to recoup costs associated with installation of a frontage water main under a front foot charge if applicable to language described above in the Frontage Main Eligibility definition. Refer to Chapter 35 Water and Sewers, Article III, Charges, Division 1, § 35-58 Assessment of Front Footage Charges for Service Connection, of the City Code for more information.
(f) The water main capacity charge is calculated by dividing the development cost by the water pipe’s net capacity. The water pipe’s net capacity is determined in accordance with the most current version if the city’s Policy and Procedure for Processing Water and Wastewater Projects for Design and Construction, using a coefficient of roughness of 120. The maximum pipe capacity will be based on a pipe friction loss of seven feet per 1,000 feet length of pipe or water velocity of seven feet per second, whichever is more conservative. The net pipe capacity is equal to the maximum pipe capacity subtract the minimum residential fire flow. Currently the minimum residential fire flow per Fort Worth fire department is 1.44 MGD, which may change with future adoption of the International Fire Code. See a table below for net capacity based on pipe size.
Maximum Design Capacity for Water Mains (12 in. to 54 in.) | ||||
Water Main Size (I.D.) | Pipe Velocity (ft./sec.) | Pipe Friction Loss (ft./1,000 ft.) | Maximum Capacity (MGD) | Net Capacity (MGD) |
12 in. | 3.55 | 7.00 | 2.3 | 0.86 |
16 in. | 5.43 | 7.0 | 4.9 | 4.86 |
24 in. | 7.00 | 7.00 | 14.2 | 12.76 |
30 in. | 7.00 | 5.37 | 22.2 | 20.76 |
36 in. | 7.00 | 4.33 | 32.0 | 30.56 |
Maximum Design Capacity for Water Mains (16 in. to 54 in.) | ||||
Water Main Size (I.D.) | Pipe Velocity (ft./sec.) | Pipe Friction Loss (ft./1,000 ft.) | Maximum Capacity (MGD) | Net Capacity (MGD) |
42 in. | 7.00 | 3.64 | 43.5 | 42.06 |
48 in. | 7.00 | 3.14 | 56.8 | 55.36 |
54 in. | 7.00 | 2.72 | 72.0 | 70.56 |
(Ord. 17623, § 2, passed 6-19-2007; Ord. 21251-05-2014, § 4, passed 5-20-2014; Ord. 23708-06-2019, § 7, passed 6-25-2019)