REPORT TO COUNCIL
SUBJECT
Title
Plan for Achieving 15 Percent Water Reduction in Parks, Including Anticipated Impact on Appearance and Functionality of Parks (Information Only)
Report
BACKGROUND
In June, 2014 Council approved adoption of a resolution declaring a water shortage emergency condition and calling for a 15 percent water use reduction through December 31, 2014 and the introduction of an ordinance to amend Title 12 of the Sunnyvale municipal Code to include additional prohibited non-essential water uses. Council also requested Department of Public Works staff to provide this report concerning water reduction and impacts for parks. This action was precipitated by California's third consecutive year of drought and the ensuing declaration of a state drought emergency in January followed by requested reductions from the City's water providers including a 10 percent reduction from the San Francisco Public Utilities Commission and a 20 percent reduction from the Santa Clara Valley Water District.
EXISTING POLICY
General Plan - Land Use and Transportation 8.2: Adopt management, maintenance and development practices that minimize negative impacts to the natural environment, such as supporting and enforcing the integrated pest management system; and landscaping in ways which minimize the need for water.
DISCUSSION
The Parks program used approximately 277,000 hundred cubic feet (ccf) of water from July through December 2013 for a variety of purposes throughout the 590 acres of open space facilities maintained including City and regional parks, school athletic fields, landscaped medians and special use areas. Although water was primarily used to irrigate athletic field and ornamental turf grass, it was also used for landscaping, ornamental ponds, water play areas, drinking fountains, recreation buildings and restrooms. Staff employ water management practices on a continuous basis that comply with all local, state and federal requirements and regulations including Municipal Code Chapter 12.34.020 which defines nonessential water uses that are prohibited and the approved amendment limiting irrigation hours from 6:00 p.m. to 9:00 a.m. and duration of irrigation per station to 15 minutes. Our goal is to reduce parks water use by 15 percent or 41,550 ccf from July 2014 through December 2014 when compared to the same period in 2013. The methods used to achieve needed water reductions are proposed for this point in time and may change as the drought improves or worsens.
Parks Plan to Achieve 15% Water Reduction
Method |
Percentage of 15% Reduction |
Reduction in irrigation run times |
65-75% |
Not filling ornamental ponds |
15-20% |
Irrigation system maintenance |
5-10% |
Ornamental Turf Reduction |
2-5% |
Total |
100% |
Water Management Practices
Computerized Central Irrigation Controller
Irrigation water use is managed by a central irrigation controller that communicates via wireless modems with 150 satellite controllers located at open space facilities. Those controllers run 3,600 valves or stations that represent 28,800 individual irrigation heads that deliver the water to the landscape. A custom program based on site conditions including plant types, soil conditions, topography and the irrigation system is entered into the satellite controller which will determine the frequency and duration that each station will run. The central controller collects data daily from three dedicated weather stations located in different microclimates within Sunnyvale that enable it to determine an evapotranspiration (the rate at which water is evaporating from the soil and through plants aerial parts) coefficient used to increase or decrease the run times a certain percentage for each satellite controller. There is also a feature that shuts down all controllers if there is measurable precipitation from rain. Irrigation programs may also have their station run times changed by a set percentage at each satellite controller or globally through the central controller. This function will be utilized to achieve 65-75 percent of the needed reduction by lowering irrigation run times for all controllers by 10 percent.
Ornamental Ponds
Parks maintains ornamental ponds at the Community Center, Braly, Serra, and Las Palmas Parks. The City's current practice calls for filling of the Community Center pond all year and the other three from Memorial Day through Labor Day. This practice has been in place for several years resulting in significant water savings at three parks which makes it more challenging to meet an additional 15 percent reduction goal.
Currently only the pond at the Community Center is filled. The pond at Las Palmas Park has been empty all summer to allow replacement of playground equipment. The ponds at both Braly and Serra Park were drained recently to complete pump repairs. Not filling the three ponds in the parks for the months of July and August will save approximately 8,000 ccf of water or 15-20 percent of the needed reduction.
Water Play Features
Many of Sunnyvale's parks have water play features for children. These only use water when in active use and account for a very small percentage of the overall usage at any park. No changes are planned to the operation of water play features, provided that drought conditions do not worsen.
Irrigation System Maintenance
All irrigation systems are imperfect and lose water from the point of connection and the backflow preventer and downstream to the individual irrigation heads. Some of the common problems that result in water loss are leaks or breaks throughout the system and heads that are not set at the right height to grade, tilted, clogged nozzle or improper coverage pattern. Staff will dedicate additional time to inspect, repair and monitor irrigation systems from July through September to ensure that they are in good operating condition and water loss is kept to a minimum thereby saving an estimated 4,000 ccf of water or 5-10 percent of the needed reduction.
Ornamental Turf Grass Reduction and Mulch
Most of Sunnyvale's parks were designed and constructed from 30-50 years ago and during that time the typical municipal park had 20-40 percent of its total area planted with ornamental turf grass types that were costly to maintain due to the amount of labor, water and goods required. Park design has significantly changed to the point where newer parks have little if any traditional, non-athletic turf grass. A good example of this is Seven Seas Park that has one acre of multi-use athletic turf grass and no traditional ornamental turf grass. Ornamental turf grass (non-athletic field) areas that are not healthy due to site conditions such as competition from tree roots and shade, serve a minimal function due to their location or condition and provide a limited contribution to the attractiveness of the area and therefore have been gradually reduced for the last five years to reduce water and maintenance costs. The process involves covering the area with mulch to minimize evaporation and weed growth and landscaping the area with low water use, perennial flowering plants in some cases. In this manner, 5 percent or 4 of the 80 acres of ornamental turf grass system-wide have been removed in that timeframe. It is anticipated that another 1-2 acres will be eliminated in this manner in the next six months. All bare soil in landscaped areas is maintained with a 3-4" layer of mulch to reduce water evaporation from the soil. These methods will save an estimated 2-5 percent of the needed reduction in water use.
Service Levels
Performance indicators in the parks program rate the safety, usability and attractiveness of open space facilities. Although a 15 percent reduction in water use can be achieved without negatively affecting the safety or usability of parks and open space facilities, it will reduce the service level for attractiveness related to athletic and ornamental turf, landscaping and ornamental ponds. Every effort will be made to minimize that impact but it will be noticeable as turf grass areas will show signs of stress, exhibit some brown areas and landscaping will also display stressed conditions. Conditions will be monitored closely and adjustments made as needed. High use areas such as sports fields will be a priority to keep in good condition.
PUBLIC CONTACT
Public contact was made by posting the Council agenda on the City's official-notice bulletin board outside City Hall, at the Sunnyvale Senior Center, Community Center and Department of Public Safety; and by making the agenda and report available at the Sunnyvale Public Library, the Office of the City Clerk and on the City's website.
Prepared by: Scott Morton, Superintendent of Parks and Golf
Reviewed by: Kent Steffens, Director, Public Works
Reviewed by: Robert A. Walker, Assistant City Manager
Approved by: Deanna J. Santana, City Manager