§ 7.5-123. Design criteria.

(1)

Generally. The criteria listed herein is not intended to cover all aspects of design, but rather to mention the basic guidelines and those particulars that are required by the city.

(2)

Water supply.

(a)

Residential water supply for domestic use shall be in accordance with the following table and at a minimum residual pressure of twenty (20) psi at the highest point in the development.

INSTANTANEOUS WATER DEMANDS FOR RESIDENTIAL AREAS
Total Number of Residences Served	GPM per Residence	Total Number of Residences Served	GPM per Residence
5	8.0	90	2.1
10	5.0	100	2.0
20	4.3	150	1.6
30	3.8	200	1.3
40	3.4	300	1.2
50	3.0	400	0.9
60	2.7	500	0.8
70	2.5	750	0.7
80	2.2	1,000	0.6

 

(b)

The city may require the following minimum available flow/duration quantities at the highest point in the development with a minimum residual pressure of twenty (20) psi measured at the nearest fire hydrant prior to development of the property.

1.

Multi-family: One thousand two hundred fifty (1,250) GPM for twenty (20) minutes.

2.

Shopping centers: One thousand two hundred fifty (1,250) GPM for thirty (30) minutes.

3.

Motels, light industry, office buildings, or schools: One thousand two hundred fifty (1,250) GPM for thirty (30) minutes.

4.

Heavy industry or warehouse: Minimum one thousand five hundred (1,500) GPM for forty-five (45) minutes.

5.

Residential: One thousand (1,000) GPM for thirty (30) minutes.

6.

Anything greater than ten thousand (10,000) square feet : IFC shall be referred to for development approval. Appendix B.

(3)

Fire protection.

(a)

Fire hydrants shall be spaced not more than five hundred (500) feet apart with additional fire hydrants located as necessary to permit all portions of buildings to be reached by hose lays of not more than three hundred (300) feet in length. (Spacing as traffic travels.) In subdivisions, hydrants will generally be aligned with the property line separating two (2) adjacent lots.

(b)

Fire lines shall be metered per these specifications.

(c)

Hose lay distance for fire truck hoses is defined as being measured along the route a piece of fire apparatus must travel in laying a fire hose from the fire to the fire hydrant.

(d)

All plans for development must meet all applicable fire protection codes.

(e)

Hydrants shall be no greater than three hundred (300) feet apart in heavy industrial zoning.

(4)

Water mains and appurtenances.

(a)

Water mains.

1.

Ductile iron pipe. Ductile iron pipe shall be used for main lines in all locations.

2.

Diameter. Main lines shall be a minimum of eight (8) inches in diameter.

3.

On existing streets. On existing roads, water lines shall be located on the south and west side of the road, nine (9) feet from the back of curb, with a minimum cover of thirty-six (36) inches below the level of the road shoulder. Fire hydrants on existing roads shall be located between the waterline and the back of curbing.

4.

On new streets. All curbing must be installed before any water lines are installed. Water lines on new streets shall be located on the south and west side of the street, as shown in the standard detail drawings. Water lines shall be installed with thirty-six (36) inches of cover at finish grade. Fire hydrants shall be located between the water main and the back of curbing.

(b)

Service laterals.

1.

Shortside service laterals shall be installed with a uniform slope from the main shallowing to a bury of twelve (12) inches at the water meter setting. Water meter settings are to be located adjacent to the right of way limit. Longside services shall have a minimum cover of thirty-six (36) inches under areas of pavement and curbing then shallowing to twelve (12) inches at the water meter.

2.

Service laterals crossing any roads shall be placed inside a minimum of a two-inch diameter PVC casing.

3.

A (W) shall be etched into the curb where each service tap is made for permanent location.

4.

Copper tubing shall be used for all services. There shall be no splices of copper tubing under any pavement.

5.

Services for subdivisions shall be sized and located as shown on the standard detail drawings.

(c)

Location of meters. Residential water meters shall be located at the limits of the street right-of-way. In general meters will be located near the property line, where possible a double yoke assembly will be utilized at the property line separating two (2) adjacent lots. The project designer is responsible for verifying electric transformer locations and avoiding conflicts. The developer shall be responsible for installing the meter box and yoke assembly. See standard details for listing of required components. The city shall install the water meter in the yoke assembly after tap fees have been paid and service applied for.

(d)

Installation. Vaults and all valve and piping assemblies for commercial and industrial meter settings shall be installed by the developer. Installations for three-fourths-inch and one-inch meter settings shall utilize a standard yoke assembly and the required additional backflow device located in a separate box. The city shall provide the meter after tap fees are paid and service applied for. No water service shall be provided until all required backflow devices are in place.

(e)

Backflow preventer. All water meters shall be provided with a backflow preventer. Residential services shall be provided with a dual check backflow preventer installed by the developer as part of the standard yoke assembly. Additional backflow prevention measures are required for residential services with lawn irrigation sprinkler systems connected. Commercial water services, as a minimum, shall be provided with a double check valve backflow prevention device installed by the developer and located immediately downstream of the meter setting in a separate vault or utility box. Additional and/or more extensive backflow prevention measures may be required depending on the type of business, materials handled and plumbing configuration. All customers applying for commercial water service are to contact the city water department backflow prevention coordinator for a determination of specific requirements concerning backflow prevention devices.

(f)

Fire line meters. Fire line meters shall be designed to meet site-specific conditions. See standard details for conceptual layout of meter.

(g)

Detector meter. Detector meters shall be designed to meet site-specific conditions. See standard details for conceptual layout.

(h)

Water valves.

1.

At intersections. Valves on water mains at intersections shall be located behind the curb. As a general rule, the number of valves shall equal the number of streets in the intersection minus one (1). The city may require valves in excess of this requirement if the water system layout warrants additional valves.

2.

At end of line. A water valve and a minimum of thirty-six (36) feet of pipe shall be provided at the end of all lines for phased developments, and at locations where the water main may be extended in the future for water system improvements. The end of the line shall be provided with a temporary plug and thrust collar designed to function in a manner that will allow for the end of the line to be excavated and exposed for tie-on of an extension without taking the main out of service.

3.

Along mains. Maximum spacing of water valves along mains shall be one thousand (1,000) feet. These line valves, unless at intersections, shall be located near fire hydrants.

(i)

Valve markers. One (1) concrete valve marker shall be furnished and set at each line valve as required by the city.

(j)

Air and vacuum release valves. Air and vacuum release valves shall be located where appropriate as determined by a registered engineer in responsible charge of the project design. All A&V release valve locations are subject to approval of the city. In general, within subdivisions A&V release valves are not necessary as long as services are located at the water main high points.

(k)

Polyethylene encasement. Ductile iron pipe water main shall be provided with polyethylene encasement where the water main either crosses or runs within three (3) feet of a steel gas main.

(l)

Easements. Water mains that are located off the public right-of-way shall have a twenty-foot permanent easement.

(5)

Line extension requirements.

(a)

Developers are required to extend all mains along their entire road frontage of the development property. The size of the extension will be at least the size of the existing main and may be larger if required by the water department.

(b)

If an existing main must be extended to serve a particular development, the developer will be required to pay all costs.

(Ord. No. 32-98, § 1, 8-27-98; Ord. No. 50-98, §§ 4, 6, 1-7-99; Ord. No. 66-07, § 1, 12-20-07; Ord. No. 67-07, § 1, 12-20-07)