§ 5.11. Water conserving landscaping.

The city's landscape ordinance (Zoning Ordinance No. 1144, section 52-35a) that was approved by the city council on December 11, 2008, requires minimum standards for landscaping that apply to all land developed within the city limits. Specifically, the following provisions are included:

• All trees and shrubs shall be from the list of approved trees and shrubs in section 52-35a(4). Grass, ground cover and other landscaping materials are encouraged to be of a type or species that is native to the area and has a low to moderate water requirement.

• Landscape areas in parking lots should be designed to allow some run-off to flow into the landscape area to help reduce the total amount of run-off.

This ordinance accepts xeriscape landscaping as an acceptable way to meet the minimum landscape standard, which provides developers an option to minimize irrigation water requirements for new development. The ordinance specifically states that ". . .a xeriscape landscape plan which reflects a variety of rock, stone, gravel, and other unpaved materials shall also qualify" to comply with the minimum landscape standards. Additionally, the parks and recreation department has developed a booklet called "A Guide to Using Native Texas Plants - Irving's Top 50 Plants to Support our Environment." This publication encourages the use of plants that thrive in typical conditions found in the Metroplex region.

In addition to the requirement for landscaping that promotes water conservation, the city recently adopted a local landscape irrigation ordinance intended to promote water conservation by eliminating reckless watering practices. During its 2007 session, the Texas State Legislature passed House Bill 1656 which focused on the responsible use of irrigation systems and professional system installation techniques. Full compliance with the ordinance will be phased in during 2009 and 2010 in order to allow businesses and residents ample time to plan for and implement the necessary changes.

As of January 1, 2009, it is now necessary for new irrigation systems to be installed by licensed irrigators. All aspects of the design and installation work must be overseen by someone with these credentials. Homeowners may still install their own systems, but they must comply with the state regulations, just as a licensed irrigator does. In all cases, the installation of a new system requires a permit and payment of the associated fee. Because of the new plan review and inspection requirements placed on the city, the fee has been adjusted to one hundred dollars ($100.00) for residential systems and one hundred fifty dollars ($150.00) for commercial systems. The city's design specifications require that irrigation systems not do the following:

• Spray onto structures like fences, retaining walls or building foundations.

• Locate sprayheads within four (4) inches of impervious surfaces such as sidewalks or buildings.

• "Spray water where landscaping is less than four (4) feet in width (drip irrigation or bubblers are required".

In order to conserve water, it is now necessary to ensure that irrigation systems are used responsibly. The new irrigation ordinance prohibits irrigating under the following circumstances:

• While any precipitation is falling (i.e. rain, snow, etc.).

• In such a way that a substantial amount of water falls upon impervious areas instead of a lawn or landscape such that a constant stream overflows from the lawn or landscape onto a street or drainage area.

• When the irrigation system has a broken or missing sprinkler head.

Another important conservation and safety feature of the ordinance involves the required installation of rain and freeze sensors. All new systems are required to install a rain and freeze sensor effective January 1, 2009. Existing commercial systems are required to have rain/freeze sensors by January 1, 2010, while existing residential systems have an additional year for the installation which must be completed by January 1, 2011.

Additionally, future seminars and city facility development will emphasize rainwater harvesting. Rainwater harvesting is a method of capturing precipitation run-off for reuse purposes. This approach does not typically fully replace the water supply necessary to support landscaping for an entire facility, but is effective in reducing the overall requirement. It is anticipated that a library facility for which planning will begin prior to the end of 2009 will incorporate rainwater harvesting components designed for instruction, demonstration and to fully supplement all of the facility's irrigation needs.

(Ord. No. 2011-9302, § 1, 12-8-11)