APPENDIX A – WATER EFFICIENT LANDSCAPE WORKSHEET This worksheet is completed by the project applicant and is a required element of the Landscape and Irrigation Documentation Package. SECTION A. GALLONS OF WATER NEEDED BY PLANT CATEGORY AND IRRIGATION TYPE The specific irrigation water needs of each hydrozone in the design should be determined using the following formula and factors: Irrigation Water Budget = [(ETo × Plant Factor) – Re] × Irrigated Area ÷ Irrigation Efficiency × 0.623 Where: ETo = Reference Evapotranspiration = 27.4 inches/season (May through September) Re = Effective Precipitation = 6.8 inches/season (May through September) Irrigated Area = hydrozone area in square feet Water Use Plant Factor Irrigation Default Category Method Efficiency Cool-Season Turf 0.90 Overhead 75% High 0.80 Drip 90% Medium 0.65 Water Feature 75% Low 0.40 Very Low 0.25 Water Feature 0.90 Special Features to Incentivize Maximum Applied Healthy Landscapes* Water Budget (% of Irrigated Area) (gal/sf/season) At least 10% 8.5 At least 5% 8.0 Less than 5% 7.5 *See Section 4.3.1.b.i. Maximum of 10% of the total irrigated area can be applied for to increase water budget up to 8.5 gal/sf/season with any combination of applicable special features. Reduction in Calculated Number of 55-Gallon Irrigation Water Need Rain Barrels** (gallons) 2 250 1 125 **See Section 4.3.1.b.ii. Water from rain barrels must be applied to irrigated plantings with Low or Very Low water use categories with drip irrigation. City of Aspen Water Efficient Landscaping Standards A-1 SECTION B. HYDROZONE INFORMATION TABLE AND WATER BUDGET CALCULATION First, complete the Special Features Table to define the Maximum Applied Water Budget and any allowed reductions to help complete the Hydrozone Table. Next, complete the Hydrozone Table for each hydrozone. Use as many rows as necessary to provide the square footage of landscape area per hydrozone. 1. Special Features Table Special Feature Special Feature Response Total area of Special Features (sq-ft) Total percent of Special Features Maximum Applied Water Budget (gal/sf/season) (a) Total number of 55-gallon rain barrels Irrigation Water Need Reduction for Rain Barrel(s) (b) 2. Hydrozone Table Hydrozone Irrig Water Plant Area Need Hydro- ETo Water Use Plant Re Irrigation Irrigation zone (in/season) Category Factor (in/season) Method Efficiency (sq-ft) (gal/season) Sub-total Irrigation Water Need Reduction for Rain Barrel(s) (b) TOTAL (c) (d) AVERAGE IRRIGATION WATER NEED ALL ZONES = (d) ÷ (c): gal/sf/season IMPORTANT: Confirm that this does not exceed value determined in (a) above. City of Aspen Water Efficient Landscaping Standards A-2 Example Hydrozone Information Table and Water Budget Calculations Example A: This landscape plan has no special features and is required to meet the 7.5 gal/sf/season Maximum Applied Water Budget. 1. Special Features Table Special Feature Special Feature Response Total area of Special Features (sq-ft) Total percent of Special Features Maximum Applied Water Budget (gal/sf/season) 7.5 (a) Total number of 55-gallon rain barrels Irrigation Water Need Reduction for Rain Barrel(s) 0 (b) 2. Hydrozone Table Hydrozone Irrig Water Plant Water Area Need Hydro- ETo Use Plant Re Irrigation Irrigation zone (in/season) Category Factor (in/season) Method Efficiency (sq-ft) (gal/season) Zone 1 27.4 L 0.40 6.8 Drip 0.90 2,000 5759 Zone 2 27.4 M 0.65 6.8 Overhead 0.75 500 4573 Zone 3 27.4 Cool-Season 0.90 6.8 Overhead 0.75 2,000 29,671 Turf Zone 4 27.4 VL 0.25 6.8 Drip 0.90 1,000 35 Sub-total 5,500 40,038 Irrigation Water Need Reduction for Rain Barrel(s) (b) 0 TOTAL ( c) 5,500 (d) 40,038 AVERAGE IRRIGATION WATER NEED ALL ZONES= (d) ÷ (c): 7.28 gal/sf/season IMPORTANT: Confirm that this does not exceed value determined in (a) above. City of Aspen Water Efficient Landscaping Standards A-3 Example B: This landscape plan includes a 400 sq-ft non-irrigated, native vegetation area, totaling 7% of the total irrigated area. This increases the allowed Maximum Applied Water Budget to 8.0 gal/sf/season. With this allowance, Zone 4 from Example A was changed from Very Low plant category with Drip irrigation to Low plant category with Overhead irrigation. This increases the Average Irrigation Water Need to 7.9 gal/sf/season, meeting the Maximum Applied Water Budget of 8.0 gal/sf/season. 1. Special Features Table Special Feature Special Feature Response Total area of Special Features (sq-ft) 400 Total percent of Special Features 7% Maximum Applied Water Budget (gal/sf/season) 8.0 (a) Total number of 55-gallon rain barrels Irrigation Water Need Reduction for Rain Barrel(s) 0 (b) 2. Hydrozone Table Hydrozone Irrig Water Plant Water Area Need Hydro- ETo Use Plant Re Irrigation Irrigation zone (in/season) Category Factor (in/season) Method Efficiency (sq-ft) (gal/season) Zone 1 27.4 L 0.4 6.8 Drip 0.9 2,000 5,759 Zone 2 27.4 M 0.65 6.8 Overhead 0.75 500 4,573 Zone 3 27.4 Cool-Season 0.9 6.8 Overhead 0.75 2,000 29,671 Turf Zone 4 27.4 L 0.4 6.8 Overhead 0.75 1,000 3,456 Sub-total 5,500 43,459 Irrigation Water Need Reduction for Rain Barrel(s) (b) 0 TOTAL ( c) 5,500 (d) 43,459 AVERAGE IRRIGATION WATER NEED ALL ZONES = (d) ÷ (c): 7.90 gal/sf/season IMPORTANT: Confirm that this does not exceed value determined in (a) above. City of Aspen Water Efficient Landscaping Standards A-4 Example C: This landscape plan includes a 650 sq-ft non-irrigated, native vegetation area, totaling 12% of the total irrigated area. This increases the allowed Maximum Applied Water Budget to 8.5 gal/sf/season. With this allowance, Zone 2 from Example A was changed from Medium plant category with Overhead irrigation to Cool Season Turf plant category with Overhead irrigation. This increases the Average Irrigation Water Need to 8.42 gal/sf/season, meeting the Maximum Applied Water Budget of 8.5 gal/sf/season. 1. Special Features Table Special Feature Special Feature Response Total area of Special Features (sq-ft) 650 Total percent of Special Features 12% Maximum Applied Water Budget (gal/sf/season) 8.5 (a) Total number of 55-gallon rain barrels Irrigation Water Need Reduction for Rain Barrel(s) 0 (b) 2. Hydrozone Table Hydrozone Irrig Water Plant Water Area Need Hydro- ETo Use Plant Re Irrigation Irrigation zone (in/season) Category Factor (in/season) Method Efficiency (sq-ft) (gal/season) Zone 1 27.4 L 0.4 6.8 Drip 0.9 2,000 5,759 Zone 2 27.4 Cool-Season 0.9 6.8 Overhead 0.75 500 7,418 Turf Zone 3 27.4 Cool-Season 0.9 6.8 Overhead 0.75 2,000 29,671 Turf Zone 4 27.4 L 0.4 6.8 Overhead 0.75 1,000 3,456 Sub-total 5,500 46,304 Irrigation Water Need Reduction for Rain Barrel(s) (b) 0 TOTAL (c) 5,500 (d) 46,304 AVERAGE IRRIGATION WATER NEED ALL ZONES = (d) ÷ (c): 8.42 gal/sf/season IMPORTANT: Confirm that this does not exceed value determined in (a) above. City of Aspen Water Efficient Landscaping Standards A-5 Example D: This landscape plan includes a 650 sq-ft non-irrigated, native vegetation area, totaling 12% of the total irrigated area. This increases the allowed Maximum Applied Water Budget to 8.5 gal/sf/season. With this allowance, Zone 2 from Example A was changed from Medium plant category with Overhead irrigation to Cool Season Turf plant category with Overhead irrigation. This property also has two 55-gallon rain barrels being used as supplementary supplies, allowing a 250-gallon irrigation water need reduction to the property. This increases the Average Irrigation Water Need to 8.37 gal/sf/season, meeting the Maximum Applied Water Budget of 8.5 gal/sf/season. 1. Special Features Table Special Feature Special Feature Response Total area of Special Features (sq-ft) 650 Total percent of Special Features 12% Maximum Applied Water Budget (gal/sf/season) 8.5 (a) Total number of 55-gallon rain barrels 2 Irrigation Water Need Reduction for Rain Barrel(s) 250 (b) 2. Hydrozone Table Hydrozone Irrig Water Plant Water Area Need Hydro- ETo Use Plant Re Irrigation Irrigation zone (in/season) Category Factor (in/season) Method Efficiency (sq-ft) (gal/season) Zone 1 27.4 L 0.4 6.8 Drip 0.9 2,000 5,759 Zone 2 27.4 Cool-Season 0.9 6.8 Overhead 0.75 500 7,418 Turf Zone 3 27.4 Cool-Season 0.9 6.8 Overhead 0.75 2,000 29,671 Turf Zone 4 27.4 L 0.4 6.8 Overhead 0.75 1,000 3,456 Sub-total 5,500 46,304 Irrigation Water Need Reduction for Rain Barrel(s) (b) 250 TOTAL (c) 5,500 (d) 46,054 AVERAGE IRRIGATION WATER NEED ALL ZONES = (d) ÷ (c): 8.37 gal/sf/season IMPORTANT: Confirm that this does not exceed value determined in (a) above. City of Aspen Water Efficient Landscaping Standards A-6 APPENDIX B – GREENCO PLANT LIST The Plant Water Use Category (VL = Very Low, L = Low; M = Medium; H = High) used to calculate the Irrigation Water Budget in Appendix A should be selected from the plant list provided in the “Green Industry Best Management Practices (BMPs) for the Conservation and Protection of Water Resources in Colorado: Moving Toward Sustainability” Appendix E, Third Release, May 2008.