SECTION 4: ARID-ADAPTED PUBLIC SPACE - ALTERNATIVE PROVISION MODELS

10. Reimagining the 10% Public Land Contribution

10.1 Core Design Principles from Arid City Precedents

Synthesizing lessons from Iranian, Greek, Arizona, and Dubai precedents:

Principle 1: Hard Surface Dominance

VD insight: Public realm should be primarily paved, with vegetation concentrated in private courtyards where water use is household-controlled.

Application to Perth:

Public = Shared + Hard + Zero-irrigation

Community plazas (permeable paving, shade structures)
Linear pedestrian streets (wide hardscape zones)
Activity spaces (courts, pump tracks—concrete/asphalt)
Pocket parks (hard surface with shade, minimal plantings)

Private = Family + Green + Controlled-irrigation

Private courtyards and gardens (household water responsibility)
Balcony/terrace plantings (resident-maintained)
Shared community gardens (member-maintained with harvested rainwater)

Benefits:

Zero ongoing public irrigation (sustainable)
Predictable maintenance costs (no exponential scaling with water prices)
Year-round functionality (not dependent on seasonal water availability)
Climate-appropriate (works in 45-50°C without artificial cooling)

Principle 2: Built Shade Mandatory

VD insight: Shade must come from structures, not vegetation requiring irrigation.

Implementation:

Tensile fabric: 80-95% UV block, minimal maintenance, 15-20 year lifespan
Pergolas with photovoltaics: Solar generation + shade (dual function)
Strategic buildings: Colonnade edges, covered pavilions
Orientation planning: North-south street axes maximize afternoon shade from buildings

Avoids:

Tree dependence (requires irrigation, decades to reach shade maturity)
Lawn dependence (requires irrigation)
"Temporary shade solutions" (umbrellas blown away, tents deteriorate)

Principle 3: Activity Infrastructure Over Passive Lawns

VD insight: Dense populations need doing-places, not just being-places. Hard infrastructure enables activity; lawns accommodate only passive recreation.

Prioritize:

Courts (basketball, volleyball, futsal—multi-use)
Skate/scooter facilities (concrete bowls, rails, ramps)
Pump tracks (asphalt berms for bikes/scooters)
Parkour infrastructure (fixed obstacles, urban design integration)
Climbing walls (installed on building facades, freestanding structures)
Outdoor fitness equipment (calisthenics, bodyweight stations)

De-prioritize:

Large lawn areas (require irrigation, serve only passive use)
Sports ovals (exclusive specialized use, 3-4% utilization)

Principle 4: Bushland Reserves for Ecological/Cultural Function

VD insight: Native vegetation serves ecological, cultural, and educational functions—not irrigation-dependent recreation.

Implementation:

Retain existing native vegetation corridors where possible
Supplement with appropriate native plantings (rainfall-dependent after establishment)
Interpret ecological/cultural significance through signage
Provide trails for walking/nature appreciation (hard surface paths)
NOT grass lawns (different ecological function)

Benefits:

Biodiversity corridors
Cultural connection to pre-colonial landscape
Educational resource
Minimal maintenance after establishment (weed control only)
Zero irrigation (appropriate species selection)

11. Complete Arid-Adapted Public Space Portfolio

Context: 1,000-dwelling development with 10% POS requirement = 10ha public land

Conventional model: 10 community sports ovals (10ha @ 1ha each)

Serves: 3-4% population (organized sport participants)
Water: 150-350ML/year
Maintenance: $450,000-850,000/year (current, escalating)

Arid-adapted alternative portfolio (same 10ha):

11.1 Hard Surface Plazas and Gathering Spaces (3ha total)

11.1.1 Central Community Plaza (1.5ha)

Design specification:

Surface materials:

Permeable paving: 70% coverage (granite pavers, 10mm joints with permeable grout)
Sealed paving: 20% coverage (high-traffic zones—sealed granite, regular cleaning)
Soft fall zones: 5% coverage (rubber surfacing under play equipment)
Planting beds: 5% coverage (native succulents, drip irrigation during establishment only, rainwater harvesting)

Shade structures:

Primary canopy: 1,200m² tensile fabric structure (central coverage)
- Height: 6-8m (air circulation, visual openness)
- Material: HDPE shade cloth (85-95% UV block, 15-20 year lifespan)
- Support: Galvanized steel columns (powder-coated, minimal visual impact)
- Drainage: Integrated gutters channeling to rainwater harvesting tanks
Secondary structures: 400m² total distributed coverage
- Photovoltaic pergolas (solar generation + shade dual function)
- Covered pavilions (enclosed on 2-3 sides, weather protection)
- Colonnade edges (building-integrated shade)

Activity zones:

Playground cluster: 400m² (separated 0-5y, 5-12y areas, inclusive design)
Youth plaza: 300m² (seating steps, informal performance space, skateable edges)
Event space: 600m² (flexible hardscape, power/water services, demountable stage footings)
Seating/gathering: 400m² (distributed bench seating, table clusters, moveable furniture)

Furniture/equipment:

Fixed seating: 60 linear meters (precast concrete, vandal-resistant)
Moveable seating: 40 chairs + 12 tables (stackable, lockable storage shed)
Drinking fountains: 4 locations (refrigerated, bottle-fill)
BBQ facilities: 2× electric BBQ shelters
Bicycle parking: 50 spaces (covered, secure)
Lighting: LED (4-6m height, pedestrian-scale, energy-efficient)

Rainwater harvesting:

Collection area: 1,600m² (shade structures + pavilion roofs)
Storage: 120,000L underground tanks (modular HDPE)
Use: Establishment watering for minimal plantings, toilet flushing in community building, drinking fountains

Estimated capital cost: $2.5-3.5M Annual maintenance: $35,000-50,000 (cleaning, furniture/equipment, lighting, structural inspection) Water use: Zero supplementary irrigation after 2-year establishment

11.1.2 Neighborhood Plazas (3× @ 0.5ha each = 1.5ha total)

Design specification (per plaza):

Surface materials:

Permeable paving: 75% (exposed aggregate concrete, decorative scoring)
Sealed paving: 15% (high-activity zones)
Soft fall: 5% (playground)
Minimal plantings: 5% (rainwater-fed natives)

Shade:

Primary structure: 400m² tensile canopy
Secondary: 150m² photovoltaic pergolas + covered seating

Activity zones:

Playground: 200m² (single age-integrated design, inclusive equipment)
Youth/teen space: 150m² (half-court basketball, parkour elements)
Seating clusters: 150m² (distributed throughout plaza)

Furniture:

Fixed seating: 30 linear meters
Moveable seating: 20 chairs + 6 tables
Drinking fountain: 2 locations
BBQ: 1× electric shelter
Bicycle parking: 20 spaces

Per plaza capital cost: $800,000-1.2M Per plaza annual maintenance: $12,000-18,000 Total (3 plazas) capital: $2.4-3.6M Total annual maintenance: $36,000-54,000

11.2 Shaded Linear Streets and Promenades (2ha total)

11.2.1 Primary Pedestrian Street (1ha = 400m × 25m)

Design specification:

Surface:

Shared zone: 12m width (permeable pavers, vehicular-rated for emergency/service access)
Pedestrian priority: 8m width (decorative paving, seating zones, planting beds)
Cycle path: 3m width (sealed asphalt, separated from pedestrian)
Edge zones: 2m width (services, furniture, minimal plantings)

Shade strategy:

Built structures: 60% coverage total
- Continuous pergola (photovoltaic roof): 300m length × 6m width = 1,800m²
- Building colonnades: 150m length × 3m width = 450m²
- Freestanding canopies: 4× @ 100m² each = 400m²

Activity integration:

Outdoor dining zones: 6× @ 50m² each (café/restaurant spillout)
Play interventions: 4× interactive elements (water play, climbing, sensory)
Fitness stations: 3× clusters (pull-up bars, parallel bars, core stations)
Seating clusters: 15× (formal bench seating, informal ledge seating)

Services:

Drinking fountains: 6 locations (every 60-70m)
Waste/recycling: Integrated bin clusters (every 40-50m)
Lighting: Continuous (integrated into pergola structure + supplementary poles)
Bicycle parking: 8 clusters @ 10 spaces each = 80 total
Electric vehicle charging: 4 stations (future-proofed infrastructure)

Rainwater harvesting:

Collection: 2,650m² (pergola roof)
Storage: 150,000L (distributed tanks under streetscape)
Use: Minimal establishment watering, street cleaning, public toilet facility

Capital cost: $3.5-5M Annual maintenance: $45,000-65,000

11.2.2 Secondary Pedestrian Streets (4× @ 250m × 10m = 1ha total)

Design specification (per street):

Surface:

Shared zone: 6m width (permeable pavers)
Pedestrian: 3m width (decorative paving)
Edge: 1m width (services/plantings)

Shade:

Pergola coverage: 30% (photovoltaic)
Building overhang: 20%
Freestanding canopies: 20%
Total: 70% coverage

Activity:

Play elements: 2× per street
Seating: 8× clusters
Drinking fountains: 3× per street

Per street capital cost: $500,000-750,000 Total (4 streets) capital: $2-3M Total annual maintenance: $30,000-45,000

11.3 Activity Infrastructure and Courts (1.5ha total)

11.3.1 Multi-Use Courts Complex (0.6ha)

Basketball/Netball Courts (4× full courts):

Dimensions: 28m × 15m per court × 4 = 1,680m²
Surface: Acrylic sport surfacing over concrete base (blue/green coloring)
Fencing: 4m height (vinyl-coated chainmesh, integrated ball return)
Lighting: LED floodlights (150-200 lux, programmable timer, community booking system)
Shade: Perimeter canopy coverage (1,000m²—spectator zones, not playing surface)
Goals: Adjustable height (basketball/netball conversion)

Futsal Court (1× court):

Dimensions: 40m × 20m = 800m²
Surface: Synthetic turf (short pile, infilled, FIFA-certified)
Fencing: 4m height with rebound boards
Lighting: LED floodlights
Shade: Perimeter seating canopy

Support facilities:

Drinking fountains: 4 locations
Seating: 80 linear meters (court perimeter)
Equipment storage: Lockable shed (200m²—community sports equipment library)
Bicycle parking: 40 spaces
Toilets/change: Combined facility (8 cubicles, accessible)

Capital cost: $1.8-2.5M Annual maintenance: $25,000-35,000

11.3.2 Skate/Scooter Facility (0.4ha)

Design specification:

Skate bowl: 600m² (3m deep, varying transitions, pool coping)
Street plaza: 1,200m² (stairs, rails, ledges, banks, manual pads)
Flow section: 800m² (berms, spines, quarters connecting elements)
Beginner area: 400m² (low obstacles, gentle transitions)

Surface: Reinforced concrete (steel-troweled, sealed, anti-slip additive) Lighting: LED poles (minimum 100 lux, dusk-to-11pm operation) Shade: 30% coverage (perimeter spectator zones, not riding surface) Fencing: 1.2m height perimeter (visibility, not security) Furniture: Bench seating (60 linear meters), drinking fountain (2×)

Capital cost: $800,000-1.2M Annual maintenance: $8,000-12,000 (surface inspection, graffiti removal)

11.3.3 Pump Track (0.3ha)

Design specification:

Circuit: 200m lap length
Width: 2.5-3.5m (dual direction, passing zones)
Features: Berms, rollers, jumps (varying difficulty)
Surface: Asphalt (engineered profile, sealed, line-marked)

Lighting: LED poles (dusk-to-11pm) Shade: None (users in motion, personal sun protection) Fencing: 1.2m height perimeter Furniture: Bench seating (40 linear meters), bike racks (20 spaces)

Capital cost: $400,000-600,000 Annual maintenance: $5,000-8,000

11.3.4 Outdoor Fitness Stations (0.2ha distributed)

Equipment:

Calisthenics cluster (4× locations): Pull-up bars, dip bars, parallel bars, abs benches
Bodyweight stations (6× locations): Step platforms, balance beams, agility ladders
Stretch zones (4× locations): Bars, benches, instruction signage

Surface: Permeable paving or decomposed granite (equipment footings in concrete) Shade: Integrated into plaza/street shade structures Furniture: Bench seating adjacent to each cluster

Capital cost: $180,000-250,000 Annual maintenance: $3,000-5,000

11.4 Native Bushland Reserves (3.5ha total)

11.4.1 Conservation Bushland (2ha)

Design approach:

Retain existing native vegetation where present (tuart woodland, banksia woodland remnants)
Revegetation: Appropriate local native species (Banksia, Allocasuarina, Eucalyptus, Acacia, native grasses)
Weed control: Annual program (herbicide spot-spray, manual removal)
Fencing: Post-and-wire rural-style (stock exclusion, bushland aesthetic)

Access:

Hard surface walking trails: 800m total @ 1.5m width = 1,200m²
Trail surface: Decomposed granite or stabilized limestone
Seating: 8× rest points (bench or log seats)
Interpretive signage: 6× panels (ecology, pre-colonial use, seasonal changes)

Water:

Zero irrigation (appropriate species selection)
Rainwater harvesting for establishment watering only (1-2 years)

Capital cost: $350,000-500,000 Annual maintenance: $18,000-25,000 (weed control, trail maintenance, signage upkeep)

11.4.2 Urban Bushland Park (1.5ha)

Design approach:

Hybrid model: Native bushland with limited hard surface intervention
Revegetation: 80% coverage (natives)
Hard surface: 20% coverage (trails, gathering nodes, viewing platforms)

Elements:

Walking trails: 600m @ 2m width = 1,200m²
Gathering nodes: 3× @ 100m² each = 300m²
Nature play area: 400m² (logs, boulders, sand, water play—natural materials)
Viewing platform: 150m² elevated deck (bushland canopy viewing)

Shade: Natural (mature native trees) + 2× shade structures at gathering nodes Furniture: Bench seating (40 linear meters), picnic tables (6×) Interpretation: 4× signage panels

Capital cost: $550,000-800,000 Annual maintenance: $22,000-32,000

11.5 Comparative Cost Analysis

11.5.1 Capital Costs Summary

Arid-adapted portfolio (10ha total):

Component	Area	Capital Cost
Central community plaza	1.5ha	$2.5-3.5M
Neighborhood plazas (3×)	1.5ha	$2.4-3.6M
Primary pedestrian street	1ha	$3.5-5M
Secondary streets (4×)	1ha	$2-3M
Multi-use courts complex	0.6ha	$1.8-2.5M
Skate/scooter facility	0.4ha	$800K-1.2M
Pump track	0.3ha	$400K-600K
Outdoor fitness stations	0.2ha	$180K-250K
Conservation bushland	2ha	$350K-500K
Urban bushland park	1.5ha	$550K-800K
TOTAL	10ha	$14.5-21.5M

Per hectare: $1.45-2.15M/ha

Sports field model comparison (10ha = 10 ovals):

Component	Area	Capital Cost
Sports ovals (10×)	10ha	$600K-1M each = $6-10M
Clubrooms (2×)	-	$1.5-2M each = $3-4M
Car parking (500 spaces)	2ha	$1.5-2.5M
Irrigation infrastructure	-	$500K-800K
Perimeter fencing/lighting	-	$400K-600K
TOTAL	10ha (+2ha parking)	$11.4-17.9M

Per hectare (excluding parking): $1.14-1.79M/ha

Capital cost comparison:

Arid-adapted: $1.45-2.15M/ha
Sports fields: $1.14-1.79M/ha
Difference: 20-40% higher capital for arid-adapted

However—arid-adapted delivers:

Zero ongoing irrigation (sports fields: $25,000-60,000/ha/year water)
Serves 60-90% of population (sports fields: 3-4%)
Year-round usability (sports fields: seasonal, weather-dependent)
Predictable maintenance (sports fields: exponentially escalating)

11.5.2 Lifecycle Cost Analysis (20-year horizon)

Arid-adapted portfolio:

Capital: $14.5-21.5M
Annual maintenance: $192,000-281,000
20-year maintenance: $3.84-5.62M
Major renewals (year 10-15): $2-3M (shade fabric replacement, court resurfacing)
20-year total: $20.3-30.1M

Sports field model:

Capital: $11.4-17.9M
Annual maintenance: $450,000-850,000
Water: $250,000-600,000/year (escalating 5-8%/year)
20-year maintenance (compounded): $10-20M
20-year water (compounded): $7-17M
Major renewals (year 10-15): $4-6M (full turf renovation)
20-year total: $32.4-60.9M

Lifecycle savings: $12.1-30.8M over 20 years (38-51% reduction)

11.6 Water Consumption Comparison

Arid-adapted portfolio:

Plazas/streets: Zero irrigation after establishment
Courts/activity infrastructure: Zero irrigation
Bushland reserves: Zero irrigation (appropriate species)
Minimal plantings (5% of hard surface areas): 10-15ML/year during establishment (years 1-2), then zero
Ongoing water use: 0-2ML/year (rainwater harvesting covers drinking fountains, toilet flushing, occasional establishment watering)

Sports field model:

10 ovals @ 15-35ML/ha/year each = 150-350ML/year
Clubroom facilities (toilets, showers, kitchens): 5-10ML/year
Car park landscaping: 2-5ML/year
Total: 157-365ML/year

Water savings: 155-365ML/year (98-99.5% reduction)

Drought resilience:

Arid-adapted: Functions identically during severe restrictions (no irrigation dependence)
Sports fields: Deteriorate to unusable brown dirt within 6-12 months of zero irrigation

11.7 Maintenance Workforce and Equipment Requirements

11.7.1 Staffing Models

Arid-adapted portfolio (10ha as described):

Required staff (FTE):

1× Parks coordinator (manages all public space maintenance)
2× Multi-skilled grounds staff (hard surface cleaning, furniture maintenance, minor repairs)
0.5× Bushland officer (weed control, ecological monitoring—shared across multiple reserves)
0.5× Horticulturist (minimal plantings maintenance—shared role)
TOTAL: 4 FTE

Comparison to sports field model (10 ovals):

1× Sports turf manager (specialist)
4-5× Grounds staff (mowing, irrigation, line marking, maintenance)
0.5× Irrigation technician (repairs, adjustments)
0.5× Agronomist consultant (turf health, soil testing)
TOTAL: 6-6.5 FTE

Staffing savings: 35-40% fewer FTE required

11.7.2 Equipment Requirements

Arid-adapted portfolio equipment:

Street sweeper: $80,000-120,000 (mechanical sweep, water wash capability)
Pressure washer (trailer-mounted): $15,000-25,000 (plaza/street cleaning)
Light truck (4×4): $50,000-70,000 (materials transport, site access)
Brushcutter/whipper snipper: $800-1,500 (bushland edge, minimal turf)
Hand tools: $5,000-10,000 (bushland work, planting, repairs)
TOTAL: ~$150,000-225,000

Sports field model equipment:

Wide area mowers (2×): $40,000-60,000 each = $80,000-120,000
Cricket mower (cylinder): $25,000-40,000
Line markers (2×): $8,000-15,000 each = $16,000-30,000
Aerator: $20,000-35,000
Top dresser: $15,000-25,000
Utility vehicles (2×): $35,000-50,000 each = $70,000-100,000
Irrigation controls/repairs: $10,000-20,000
Small equipment: $20,000-35,000
TOTAL: ~$256,000-405,000

Equipment savings: 40-45% lower capital investment

Operational advantages:

Arid-adapted: Equipment multi-functional (sweeper for streets + plazas)
Sports fields: Specialized equipment (mowers only for turf, limited alternative use)
Arid-adapted: Lower fuel consumption (less mowing, more cleaning)
Sports fields: High fuel use (constant mowing, irrigation pumping)

End of Section 4