Title
Consider public testimony regarding, and an ordinance amending Zoning and Development Code, Chapter 1, Section 1-50, and Chapter 8, Sections 8-10 and 8-40, Code of Ordinances (2018 Edition), regarding landscaping, irrigation, and screening requirements. (First Reading)*
Body
Background: In response to a directive from City Council to enhance the city's water conservation efforts, the Public Works and Planning & Development Services Departments partnered on an initiative to research and propose opportunities for revisions to the Development Code that would increase water conservation by decreasing irrigation consumption for Code-required landscape areas. After studying landscape codes from other municipalities, evaluating xeriscaping options, researching types of turfgrass and ground preparation, and considering the financial impacts of such amendments to the development community, staff identified targeted revisions to the Code that will reduce water utilization and preserve the city's natural resources.
Additionally, other deficiencies were identified by staff in the landscape and screening code because they were not prescriptive enough to result in landscaping that served the intended purpose, or they were requiring landscaping that did not provide value to the community. Finally, with the growing prevalence of smaller single-family lots, staff have observed the current tree requirement for individual residential lots to be problematic because it results in too many large trees in too small of an area without room to grow, which will ultimately result in conflicts between the trees and other structures. Revisions have been included with this amendment to resolve those issues.
Proposed Revisions:
Reducing Non-Functional Turfgrass
Turfgrass varieties commonly installed on both residential and non-residential sites have high water needs and, during the many dry months we have in central Texas, require irrigation to survive. In addition, many areas of turfgrass on non-residential sites are nonfunctional, meaning they are purely decorative and not utilized for civic, community, or recreational purposes. Some of these turfgrass areas are very small, such as grass strips between sidewalks and streets, and difficult to irrigate without wasteful overspray. There are new seed blends which include native buffalo grass varieties (Habiturf, Native Sun Turf, and Thunder Turf) that produce deeper roots and are much more drought tolerant than more commonly installed turfgrass varieties, but maintain a similar aesthetic. There is also scientific data that links deeper prepared soil depth to the increased water uptake and viability of landscape plantings.
Staff’s goal is to provide options for the development community while reducing large areas of nonfunctional turf and promoting the more drought tolerant turfgrass varieties which require less water. Therefore, we have proposed code revisions that prohibit turfgrass installation in the small strips between sidewalks and street rights of way, increase the minimum improved soil depth for turf areas from four to six inches, and provide developers with the option to either limit turfgrass areas to no more than 50% of the areas not covered by impervious surface or to have no limitation on the amount of turfgrass where the native seed blends referenced above are specified and installed.
Staff anticipates these revisions will result in measurable water conservation in the city and significant irrigation cost savings to developers and end users, which offset the increased initial costs to the development community that are incurred due to some of the proposed changes.
Screening
The landscape and screening codes currently require the planting of shrubs for screening of parking lots and ground level utilities; however, there are no criteria for those shrubs. The intent of parking lot landscape buffers is to provide a screen between parking areas and the street to a height of three feet, which is the average height of vehicle headlights. The intent of screening for ground level utilities is to hide the appearance of unsightly utility boxes, transformers, and HVAC units by providing a visual living screen.
Staff have observed the plant material commonly provided in these instances is deciduous which would not provide year-round screening and/or of a species that will not grow to three feet in height, completely negating the intent of the screen. Therefore, we have proposed a code amendment that would require such material to be evergreen and installed at a minimum height of two feet to ensure it achieves the purpose of providing a year-round visual screen within a reasonable time period from installation.
Next, the current screening requirements require dumpster and waste handling areas to be screened by a decorative masonry enclosure with an opaque gate. There is a secondary requirement to provide shrubs around three sides of the enclosure; however, staff believe this requirement is unnecessary due to the decorative nature of the enclosure and that fact that we do not require planting at the base of other decorative masonry walls. We have proposed to remove the shrub requirement at the base of the enclosures from the code because it does not yield enough benefit to the community to justify the cost to developers.
Tree Requirements for Residential Lots
Finally, the existing landscape code includes two categories of tree requirements for single family lots. The first applies to lot widths up to 80 feet and the second applies to lot widths greater than 80 feet. These lot widths are outdated because the development pattern in Round Rock has trended toward smaller lots over the last decade. For example, the SF-3 (Single-family Mixed Lot) zoning district supports smaller lots and includes a mix of lot sizes, all of which have minimum lot widths less than 80 feet. The City's Tree Technical Manual and the code require that large trees be spaced 40 feet apart and optimally 30 feet from buildings, but no closer than 12 feet from a building.
Staff have found the current tree requirement for lot widths greater than 80 feet wide is rarely applied due to the prevalence of smaller lots. Having the same tree requirement for lots less than 80 feet wide is problematic because it results in too many trees planted too close together that do not comply with tree spacing requirement. This scenario also increases the potential for conflicts between trees, easements, and underground utilities, and frequently results in a situation in which only one of the required trees survives beyond a few years.
The proposed code revision enacts three categories of tree planting requirements based on what is reasonable for the various lot widths, accounting for the reduction in planting area due to the driveway, and appropriate tree spacing requirements.
Planning and Zoning Commission: The Planning and Zoning Commission voted in favor of the Code Amendment by a vote of 5-3. The Commissioners voting against the item had concerns about the reduction of trees on residential lots, the removal of the requirement for shrubs at the base of dumpster enclosures, and the lack of enforcement for maintenance of required landscape materials on single-family lots after occupancy. There were no public speakers for this item.