3B Public Hearing 2010 0119 - Laserfiche WebLink

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(N) Sprinkler heads and other emission devices shall have matched precipitation rates, unless otherwise directed by the manufacturer's recommendations. (O) Head to head coverage is recommended. However, sprinkler spacing shall be designed to achieve the highest possible distribution uniformity using the manufacturer's recommendations. (P) Swing joints or other riser-protection components are required on all risers subject to damage that are adjacent to high traffic areas. (Q) Check valves or anti-drain valves are required for all irrigation systems. (R) Narrow or irregularly shaped areas, including turf, less than eight (8) feet in width in any direction shall be irrigated with subsurface irrigation or low volume irrigation system. (S) Overhead irrigation shall not be permitted within 24 inches of any non-permeable surface. Allowable irrigation within the setback from non-permeable surfaces may include drip, drip line, or other low flow non-spray technology. The setback area may be planted or unplanted. The surfacing of the setback may be mulch, gravel, or other porous material. These restrictions may be modified if: 1. the landscape area is adjacent to permeable surfacing and no runoff occurs; or 2. the adjacent non-permeable surfaces are designed and constructed to drain entirely to landscaping; or 3. the irrigation designer specifies an alternative design or technology, as part of the Landscape Documentation Package and clearly demonstrates strict adherence to irrigation system design criteria in Section 492.7 (a)(1)(H). Prevention of overspray and runoff must be confirmed during the irrigation audit. (T) Slopes greater than 25% shall not be irrigated with an irrigation system with a precipitation rate exceeding 0.75 inches per hour. This restriction maybe modified if the landscape designer specifies an alternative design or technology, as part of the Landscape Documentation Package, and clearly demonstrates no runoff or erosion will occur. Prevention of runoff and erosion must be confirmed during the irrigation audit. (2) Hydrozone (A) Each valve shall irrigate a hydrozone with similar site, slope, sun exposure, soil conditions, and plant materials with similar water use. (B) Sprinkler heads and other emission devices shall be selected based on what is appropriate for the plant type within that hydrozone. (C) Where feasible, trees shall be placed on separate valves from shrubs, groundcovers, and turf. (D) Individual hydrozones that mix plants of moderate and low water use, or moderate and high water use, may be allowed if: the plant factor of the higher water using plant is used for calculations. (E) Individual hydrozones that mix high and low water use plants shall not be permitted. (F) On the landscape design plan and irrigation design plan, hydrozone areas shall be designated by number, letter, or other designation. On the irrigation design plan, designate the areas irrigated by each valve, and assign a number to each valve. Use this valve number in the Hydrozone Information Table (see Appendix B Section A). This table can also-assist with the irrigation audit and programming the controller. (b) The irrigation design plan, at a minimum, shall contain: (1) location and size of separate water meters for landscape; (2) location, type and size of all components of the irrigation system, including controllers, main and lateral lines, valves, sprinkler heads, moisture sensing devices, rain switches, quick couplers, pressure regulators, and backflow prevention devices; (3) static water pressure at the point of connection to the public water supply; (4) flow rate (gallons per minute), application rate (inches per hour), and design operating pressure (pressure per square inch) for each station; (5) recycled water irrigation systems as specified in Section 492.14; 16