~ Respecting Water ~ Innovative Water Conservation and Management on the San Francisco State University Campus Presented by: Phil Evans Director, Campus Grounds August 2, 2008 UC/CSU/CCC Sustainability Conference Cal Poly San Luis Obispo

ASSESS where, why, and how water is being used CONSERVE water in campus landscape uses REINTEGRATE campus water into natural water cycle RECLAIM rainwater for campus landscape uses APPRECIATE water through education and interpretation Guiding Principles Respecting Water

Orientation- Neighborhood Respecting Water ASSESS

Identifying Water Sources and Distribution on Campus Respecting Water ASSESS

Mapping the Existing Campus Infrastructure storm drain inlets, drainage networks, and catchment areas Respecting Water ASSESS

Mapping Campus Impermeability 71% Impermeable (Roofs and Paving) 29% Permeable (Landscaping) Total for Study Area: Respecting Water ASSESS

Auditing Current Irrigation Use Respecting Water ASSESS

Planning for City-Supplied Recycled Water Respecting Water ASSESS

Transforming Lawns to Water Conserving Gardens Typical Underutilized LawnProposed Improvements Respecting Water CONSERVE

Example- Irrigation System for the Humanities Building Program 1: Spray Heads for Shrubs and Turf (31,130 square feet) Annual Water Use: 310,275 gallons (414 CCF, 0.95 acre-feet/yr) Program 2: Drip Irrigation for Shrubs (8,572 square feet) Annual Water Use: 87,771 gallons (117 CCF, 0.27 acre-feet/yr) Total: 398,045 gallons annually! Auditing Current Irrigation Systems for LEED Compliance Finding- Gallons-per-area for drip system were as high as spray head areas… Drip irrigation systems need to be carefully designed for the appropriate landscapes. Using a drip system for sandy soils or closely spaced landscape planting may not be the best solution both methods distribute about 10 gal./s.f. Respecting Water CONSERVE

Designing Infiltration Areas Respecting Water REINTEGRATE

Designing Infiltration Areas Respecting Water REINTEGRATE

Step 1: Quantify runoff based on permeability and rainfall data Stormwater Management Planning for LEED Certification Step 2: Delineate catchment basins Step 3: Analyze drainage patterns and designate infiltration areas Respecting Water REINTEGRATE

Urban Forest Stormwater Management Planning for LEED Certification Respecting Water REINTEGRATE Habitat Courtyard Rain Garden Designating Landscape Zones

Guiding Stormwater into Infiltration Ponds roof runoff diversion 1 stormwater detention 2 bioremediation and recharge 3 Respecting Water REINTEGRATE

Alternative Solutions- Rainwater Storage or Infiltration? Respecting Water REINTEGRATE $13,300 for water collection

Respecting Water REINTEGRATE From the California Stormwater BMP Handbook for New Development, Section 5.5, 2003 edition. Calculating the volume needed to capture stormwater runoff onsite for infiltration: 1.Measure entire drainage area (10,258 s.f.) and areas of each type of surface as a percentage of the entire area 20% gravel paths 43% planting beds 37% roof Alternative Solutions- Rainwater Storage or Infiltration?

Respecting Water REINTEGRATE From the California Stormwater BMP Handbook for New Development, Section 5.5, 2003 edition. Calculating the volume needed to capture stormwater runoff onsite for infiltration: Standard Runoff Coefficients Gravel paths 0.5 Concrete Paths0.95 Planting beds 0.25 Roofs Assign runoff coefficients to each type of surface, and calculate the composite runoff coefficient: (coefficient A x % of coverage/100) + (coefficient B x % of drainage area/100) + (coefficient C x % of coverage/100) = composite runoff coefficient = x x x Alternative Solutions- Rainwater Storage or Infiltration?

Respecting Water REINTEGRATE From the California Stormwater BMP Handbook for New Development, Section 5.5, 2003 edition. Calculating the volume needed to capture stormwater runoff onsite for infiltration: 3.Referring to local rainfall data, determine a unit basin storage volume (assuming a 48 hour drawdown and a goal to capture 85% of stormwater) (0.4”, or 0.033’) Curve for composite runoff coefficient of % Alternative Solutions- Rainwater Storage or Infiltration?

Respecting Water REINTEGRATE From the California Stormwater BMP Handbook for New Development, Section 5.5, 2003 edition. Calculating the volume needed to capture stormwater runoff onsite for infiltration: 4.Calculate required capture volume of the infiltration area: drainage area x unit basin storage volume = capture volume (10,258 s.f. x 0.033’ = 339 c.f.) Decorative Cobble Filter Fabric Sorted Drain Rock Sand Soil Alternative Solutions- Rainwater Storage or Infiltration?

Respecting Water REINTEGRATE From the California Stormwater BMP Handbook for New Development, Section 5.5, 2003 edition. Calculating the volume needed to capture stormwater runoff onsite for infiltration: 5.Determine the size of desired infiltration trench with consideration of porosity of fill material: required capture volume / percent porosity of fill material From Lower porosity in unsorted mixes because voids are filled with small particles Higher porosity in well-sorted particles (339 c.f./0.25 = 1356 c.f., or approximately a 70’ long x 5.5’ wide x 3.5’ deep trench) Alternative Solutions- Rainwater Storage or Infiltration?

Respecting Water REINTEGRATE From Porosity Ranges for Sediments MaterialPorosity (%) sand or gravel, well-sorted25-50 sand and gravel, mixed20-35 silt35-50 clay33-60 (Based on Meinzer (1923a); Davis (1969); Cohen (1965); and MacCary and Lambert (1962) as quoted by C.W. Fetter 2 ) 2 Material Average Specific Yield (%) coarse gravel22 fine gravel25 coarse sand27 fine sand21 silt18 clay2 (Johnson (1967) as quoted by C.W. Fetter 2 ) 2 Specific Yield for Sediments Alternative Solutions- Rainwater Storage or Infiltration?

Respecting Water REINTEGRATE $3,500 for infiltration Alternative Solutions- Rainwater Storage or Infiltration?

Storing Rainwater for Irrigation Use- HARVEST, STORE, USE Respecting Water RECLAIM

Respecting Water RECLAIM Storing Rainwater for Irrigation Use- HARVEST, STORE, USE USE STORE HARVEST

Modeling for Rainwater Catchment Feasibility $2 Million! $250,000! Respecting Water RECLAIM

Investigating Rainwater Catchment Logistics Alternative Storage and Pumping Options Pillow bladder tankUnderground cistern tankCorrugated galvanized steel tankRetention pond Household-scale wind turbineSolar water pump- direct driveSolar water pump- battery system Respecting Water RECLAIM

Respecting Water APPRECIATE Designing Holistically gardens that store runoff, recharge groundwater, conserve water, and provide habitat

Designing Gardens with Low Water Use and High Habitat Value for birds, butterflies, plants, and people! Respecting Water APPRECIATE

…biofilters that clean water for Lake Merced recharge… Creating a Campus Water Path …recreated creek channels through campus… …infiltration areas… …art installations that raise water awareness… …gateway features that use harvested rainwater… Respecting Water APPRECIATE

Planning for Rainwater-Fed Water Feature Awnings (12): 678 SF Northeast Roof Top: 1075 SF Annual Runoff: 23,966 gallons Respecting Water APPRECIATE

Thank You! Student Contributors: Vinita Huang – UC Berkeley Daniel Hui – UC Davis Elizabeth Reiff - SFSU Melissa Woo- CalPoly SLO Xiaojun Xu- UC Davis Theresa Zaro- UC Berkeley Respecting Water