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CC Resolution No. 8807 81,054.5 RESOLUTION NO. 8807 OF THE CITY COUNCIL OF THE CITY OF CUPERTINO ADOPTING GUIDELINES FOR PLANT MATERIALS, LANDSCAPE DESIGN PARAMETER AND MAINTENANCE, SOIL PREPARATION, WATER FEATURES AND IRRIGATION DESIGN AND OPERATION WHEREAS, on January 4, 1993, Ordinance No. 1615 adding Xeriscape IJln,¡.....pe procedures. Further, the Planning Commission and City Council allow staff at their own discretion additions, deletions or modifications to the Guidelines of this Ordin~nN!. SECTION 1: PLANT MATERIALS r Jlndscaping shall emphasize water conserving plant materials. New l~n'¡"""ping shall equal or ex<:eed surrounding l~n'¡"""Ping in terms ofvisual quality, empbasizing varieties of material type, texture and color. Section 1.1 Plantinll Zones: The project site should be classified into planting zones with planting materials grouped according to the water use characteristics of these zones. The similar planting zones may overlap each other where the respective planting zones have similar watering requiIements, or when planting zones with differing watering requirements can be efliciently irrigated. Planting zones requiring the greatest degree of water consumption should be sited for maximum scenic advantage. Section 1.2 Ground Covers: In general, low growing shrubs and ground covers should be substituted for lawn on slopes to retard runoff and increase on-site water retention. Section 1.3 TurfTvDes: Turfvariety should be moderate water using variety such as tall, fescue Hybrids (Festuca Arun'¡in~~ "Alta", "Falcon", "Rebel", "Jaguar") or Hard Fescue Hybrids "Fescue Durer" "Sca1dis", "Reliant", "Tournament" ) rather than blue grass or ryegrass varieties. Section 1.4 Water Con<elVÎl\lI Plants: New landscaping should use water conserving plant materials that are native to or are adapted to a hot dry $I'mm..../cold wet winter climate. Non-nativcladapted varieties that require large amounts of irrigation to survive the hot dry 'nm~ season should be avoided. A geocral1isting of native and adopted plants species may be found in the fonowing sourtI:S: Water Conservinll Plants ~nd r JlntI.......... for the Bav Area. published by the East Bay Municipal Water District. A LaDtI<=tinll Guide Native the Nah,,,,li7M Plants for Santa Çlara Countv. published by the Santa Clara Valley Water District. Snn~ Western Garden Book. Lane Publishing Company, Menlo Park. Snn~ M¡o",,:rine Remint on drought tolerant plants, October 1976, Lane Publishing Company, Menlo Park. SECTION 2: LANDSCAPE DESIGN PARAMETERILANDSCAPE MAINTENANCE Section 2.1 C.....t.. Sh~tI..· Trees should be planted to shade buildings; partial shade should also be provided to planting beds that are by reducing water evaporation from these areas. r .:ontl""'IpC areas shall be watered card'ulIy and completely maintained to ensun: adequate watering absorption and retention. Landscape maintenance should include the fonowing: Section 2.2 Parkinll Lot Trees: Trees to be located in parking areas should be ïnstaned in a l~ntI.....pe wen. The minimum dimensions are to be 8 ft. by 16 ft. in order to provide adequate oxygen and water to the root zone, and to prevent "heatburn" of the tree canopy. This l~ntI"""P" wen design can be acx:omplished by clustering four compact parking spaces (with a 2 ft. vehicle overhang) 1Iemoen standard size parking spaœs. Resolution No. 8807 Page -2- January 4, 1993 Section 2.3 r Jlntl.."."" D",ina2C: r Jlntl"<'lpe areas should drain away from building, parking and public street areas. Section 2.4 Turf Areas: Turf should be provided in functional areas such as gathering places, athletic fields, etc.; turf areas solely for the aesthetic purposes should be avoided. Section 2.5 Curbs and Gutters: r .:ontl""'IpC areas should be separated from driveways and parking areas for a poured-in-pIaœ, concrete curb or cwb-and-gutter to prevent water leakage to the pavement area. Section 2.6 Turf CoveraIlC: Combine turf and/or water area: (i.e., pool, ponds, fountains) should be limited 25% of landscape areas. For schools and public parks a higher percentage of turf may be allowed for playing in athletic fields. Section 2.7 Soecial Interest Ornaml!ntRl.~ In addition to turf, up to 10"Æ. of the planted area may be used for a special interest ornamentals (annuals, perennials and bulbs) that are low water using plant species. Special interest ornamentals should be located in the focal points of the project (i.e. by driveway entrances, building entries, etc.). Section 2.8 Turf Slooe: Turf areas should not ex<:eed a 10% slope. Section 2.9 Terracinll: Where appropriate, terracing should be used to discourage nmoIf from irrigated slope areas. Section 2.10 Minilt1um Turf Areas: The minimum tliml!n';on of any turf area should be IS ft. r JlntlCN\ )C areas with tlimensions of less than 15 ft. should be planted with DOn turf materials. Section 2.11 Small Area Alt~riws, Alternative planting materials for narrow l~ntI"""P" strips, traffic median islands and slope areas should consist of water conserving plants, shrubs, ground covers and trees. Section 2.12 TurflTree Seoaration: Turf should be separated from new trees to prevent over watering of the tree, surface rooting, crown rot, and "girdling" of the tree trunk by maintenance equipment The minimum separation should be from 3 to 5 ft. Ground cover, rocks and/or shrubs should be planted within this area. Section 2.13 Turf Tree r..,itl..Hl1es: Trees should not be planted in a turf area; lawns generally need some exposure, and prolong .hRtIillg raises their roots closer to the surface. A small number of trees may be placed in turf area "islands" which consist of 8 ft. - 16 ft. radius of open soil measured from the tree trunk. The surface mulch should be added to the soil area as wen. Section 2.14 Berm Tree PI.............: Where berms are used, trees should be ïnstaned on the "toe" of the berm slope rather than on the berm "crown". On the front side, trees should be instaned in curb-side tree wens or larger planting areas. Street and project trees should be planted in the triangu1ar pattern to shade the pedestrian sidewalk and project berm areas. Section 2.15 Berm Slooes: Berm slopes should not exceed 250/.. Section 2.16 TurfMaintl!Mnœ: De-thatch and aerate Iawns regularly to promote deep healthy roots. Section 2.17 MowinII r .....Ilth: Mow cool season grasses to a minimum height of 2 to 3 inches from grade. Section 2.18 Mulchinll' Mulch Ipntl"""P" areas regularly to reduce evaporation, moderate soil temperatures and discourage weeds. Section 2.19 F..rriH7inll: Apply fertilizer adequately, but do not overfertilize. Plant materials are less able to tolerate dry conditions when overfertilized. Resolution No. 8807 Page -3- Janwuy 4, 1993 SECTION 3: SOIL PREPARATION Cupertino soils are predominately clay and clay loam. These soils retain water well, but drain poorly and have little natural irrigation. Thus, clay soils tend to compact natura11y and prevent aeration of the plants rooted therein. Section 3.1 Soil Test: Site specific soil tests should be performed as part of the design preparation process. Section 3.2 Soil AmentltneTlts: Soil should be amended to improve infiltration, water retention and structure. Loose compost with sand or tanbarlt is p.d'.:u..d to ensure adequate irrigation. For water intensive plants, 50-70";" of the planting zone should be amended with loose compost. For less water intensive plants, compost amendment of the plant hole only is genera11y sufficient. Section 3.3 Soil Additives: Mulch should be placed on top of soil and worked into the surface. Mulch will hold irrigation water where it is applied for a longer time than will exposed soil. SECTION 4: WATER FEATURES Water features lose water to evaporation, bottom seepage, plumbing leakage and "wind-<:arry" for spray and mist- type fountains. Decorative water features, especially spray and mist-type fonnt~in.. are discouraged. Functional water features may be allowed provided that the water feature is integral to a required or desired project function and/or operation. Evaporation from still water can equal the evapotranspiraton from turf. There are two types of water features: 1. Decorative water features typically include reflective pools and ponds, spray and mist-type fountains. They function only as a visual feature and are typically single water users in that they do not reuse or capture other irrigation or storm water runoft; nor is there wastewater reused for other project operations. 2. Functional water features provide a visual amenity and are integral to a required or desired project operation. Examples include: swimming pools or other recreational amenities for poitt..ntial projects; water falls and "puddling" type fountains to create "white noise, " holding ponds for HV AC equipment water. Section 4.1 Water Linin",,: An water features should have impermeable 1inings. Section 4.2 Decorative Water Trade-OffiI: For purely decorative water features which do not include a spray or mist-type fountain, 0.5 sq. ft. of turf will be subtracted from the project's turf area allowance for each square foot of water area. If the decorative water feature includes a spray or mist-type fountain, 1 sq. ft. of turf area will be subtracted for each 1 sq. ft. of water area. Section 4.3 Functional Water Trade-OffiI: For functional water features, the maximum allowed turf area will not be reduced. Section 4.4 Pool Covers: To reduce water or loss due to evaporation, swimming pools or spas located outdoors should be covered when not used. Section 4.5 Fountain and Droullh..: Decorative fountains may not be operated during the periods of drought as declared by City Council Resolution. SECTION 5: IRRIGATION SYSTEM DESIGNIOPERATION Traditiona1ly, spray heads have been the most common irrigation application devices used in Cupertino landscape schemes. Spray head systems can irrigate a variety of plant zones effectively if the control clock is properly managed, and the watering schedule matcbes the irrigation exposure period to the plant zone absorption rate. Resolution No. 8807 Page -4- January 4,1993 Low volume sprinkler heads, drip emitters and bubbler emitters should be used to irrigate landscape areas less than 8 ft. wide. Low volume sprinkler head emit less than 0.85 inches per hour precipitation. A plant's water need is determined by the rate of evapotranspiration (ET) for the l~nd.....pe area. ET is the amount of water that evaporates from the soil plus the amount that transpires through the plant leaves. ET varies by the type of plant, air teruperature, wind and solar exposure and soil type. The eflicient operation of irrigation equipment will not be subject to City inspection after the final building inspection and occupancy certification phase. However, owners of the completed irrigation system should maintain it to assure adequate watering of land"",?, areas. Owners are further encouraged to include the fonowing components of an orvni7-"C1 maintenance plan: Section '.1 Automatic Controners: Irrigation should be controned by an automatic c:ontroner having multi programming capabilities. The fonowing c:ontroner irrigation schedule is generally appropriate for plant zones with various water needs characteristics: Turf area: Water intensive plants: Established plant zones: Drought tolerant plant zones: Every third day Every fourth day Twice per month Once per month Section '.2 Valve Service TvDes: Each irrigation valve should service only land.....pïng materials of similar short- term and long-term watering needs as wen as similar plant types, activity areas, wind exposure, sun exposure, focus areas in the micro-c1imates created within a project. Section 5.3 Match Rates: Irrigation heads and emitters should have matched precipitation rates within each control valve circuit Section 5.4 Irrill3tion Head S1"'cinll: Space spray irrigation heads evenly, with their "throw" radius generously overlapped. Overlap for turf area should be 1000/0; for ground cover areas, 75%. Section 5.5 Drin Emitters: Drip emitters are the most eflicient means ofwatering shrubs, but requiJe sophisticated knowledge to maintain. Use of drip emitter systems in 1arge projects with capable main'~nce personnel is encouraged. However, spray heads can be used to irrigate shrubs in areas over 8 ft. wide if appropriately managed. Section 5.6 Tree Irrill3tion: Trees should be irrigated with bubbler heads. Section 5.7 Circuit Valve Controners: Each circuit valve should have individual flow and IRSSUR control to prevent spray heads from misting and p..tltllillg Section 5.9 ¡lain Senmn.. Device: Use rain sensing devices with automatic sprinkler systems to avoid redundant irrigation activity. Single family residential projects are exempt from this requirement Section 5.10 Moisture s..n""",: Moisture sensing devices should be located in all turf areas, and at the high and low point of bermed turf areas in order to control irrigation cycles according to specific irrigation requirements, and to avoid overwatering. Section 5.11 Run-off Irrill3lÏon ManR""",,,,,t· Irrigation run-off should be conected in an on-site retention system and released back to planted areas, rather than be allowed to run-off to the storm drain network. Section 5.12 Check Valves: Serviceable check valves should be ïnstaned where elevation differential may cause low head drainage. Section 5.13 PoD-Un SDrinklers: "Pop-up" sprinklers located in turf areas should have at least a 4 inch pop-up height above the turf area. Resolution No. 8807 Page -5- Janwuy4,1993 Section 5.14 Water Audits: Perform watering audits seasona1ly during the first year after Ilndscaping instanation, and at least annua1ly once plantings are established. For turf areas, examine soil, depth of rooting and water penetration by using the sampling tube (a device that remove soil cores for close e"amination). If moisture depths ex<:eeds 6 to 8 inches for turf, water more frequently for shorter periods. If moisture depth falls short, increase watering time. Section 5.15 Waterinll Hours: Generally, landscaping should not be irrigated during the daylight hours. The actua1 irrigation schedules should be set by a plant zone water requirements, described in this ordinance and should be adjusted based on the observations of the actua1 ET rates and other conditions identified during the annual water audit Section 5.16 Water SV<tl!m Ch...,Ir-UD: Check sprinkler systems regularly for leakage, worn and damaged heads, poor coverage and overspray. Clean, adjust or replace hardware as D~Sruy to maintain the design efliciency of the system: 1. Instan a screenI"Y" filter at the point of connection and clean it regularly. A drip system should have its own fine mesh "Y" filter as wen. 2) Flush an 1atera11ines regularly to avoid loss of system pressure. Use regular chlorination to flush buildup ofbiologica1 material from drip system components. 3) Operate each valve from the controner to ensun: that it is functioning properly. INTRODUCED AND ENACTED at a regular meeting of the City Council of the City of Cupertino on this 4th day of Janwuy, 1993 by the fonowing vote: Ym AYES: NOES: ABSTAIN: ABSENT: Members of the City Council Dean, Goldman, Sorensen, Szabo None Koppel None APPROVED: /s/ Nick Szabo Mayor City of Cupertino ATTEST: /s/ Dorothy Cornelius City Clerk 1'......--.