Decentralized Irrigation methods to sustain LID in Arid climates. Dasch Houdeshel, M.S. and Christine Pomeroy, PhD, P.E.

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1 Decentralized Irrigation methods to sustain LID in Arid climates Dasch Houdeshel, M.S. and Christine Pomeroy, PhD, P.E.

2 Plant recommendations for bioretention in cold desert climates: Part 2 Populate with vegetation pictures Dasch Houdeshel, M.S. and Christine Pomeroy, PhD, P.E.

3 Objectives 1) To test alternative irrigation methods and demonstrate these methods to University of Utah Facilities Management 2) To continue to improve our recommendations of regionally appropriate plants for LID in arid climates

4 Background Green Infrastructure management approaches and technologies infiltrate, evapotranspire, capture and reuse stormwater to maintain or restore natural hydrologies EPA GI homepage

5 Background Cold Desert Hydrology: Winter = precipitation, storage (snow, infiltration) Spring = groundwater recharge, runoff Early Summer = Plant transpiration rates high Late Summer = deep rooted plants access groundwater Fall = some precipitation, plants go dormant before winter

6 Background Component Cost per foot 2 Total Cost % of Total Cost Excavation/labor $1.33 $2,000 30% Storage Layer Media $1.40 $2,100 31% Filter/Growth Media $0.00 $0 0% Decorative Rock $0.40 $600 9% Geotextiles $0.20 $300 4% Plants $0.27 $400 6% Irrigation $0.87 $1,300 19% Total $6, % Plus, working out the irrigator system was by far the BIGGEST administrative battle, costing designers and managers hours of meetings!!

7 Meldrum Site Description Department wanted new building to be a Student Showcase Allowed opportunity for students to participate in design and construction Opportunity for collaborative work effort and funding inputs SCIF, Civil Department, Layton Construction, students from Law, Biology, and Engineering, U of U facilities management 1:1 garden to drainage area

8 Meldrum Site Description Native soil Topsoil Utelite 1. Gravel infiltration bay to promote flow of small runoff events to storage layer 2. No liner or underdrain to maximize infiltration into native soils 3. Weed barrier under decorative rocks replace mulch to minimize evaporative loss of shallow water moisture and weed growth 4. Deep rooted plants that can access infiltrated water in summer 5. Curbs act as flood containment in big storms, roots act to promote infiltration rates

9 What to do with a rain garden that has a 1:1 drainage area? Study Irrigation!!! Decentralized Centralized Control Decentralized Traditional Ollas pots Standard University Drip Bucket and Wick

10 What to do with a rain garden that has a 1:1 drainage area? Study Irrigation!!! Bucket Drip Zone Conventional Irrigation Zone Ollas Zone 2 Ollas Zone 1

11 350% 300% 250% 200% 150% 100% 50% 0% 50% 100% And then it rained October Percent of average monthly precipitation November December January February March April May June July August

12 So we ended up with soil moisture data demonstrating cold desert bioretention hydrology Olla rhus 25cm Olla Rhus 50cm 0.3 M 3 water /M 3 soil Field Capacity /14 5/21 5/28 6/4 6/11 6/18 6/25 7/2 7/9 7/16 7/23 7/30 8/6 8/13 8/20

13 So we ended up with soil moisture data demonstrating cold desert bioretention hydrology M 3 water /M 3 soil Drip Mahogany 25 cm Drip Mahogany 50 cm 0.2 5/14 5/21 5/28 6/4 6/11 6/18 6/25 7/2 7/9 7/16 7/23 7/30 8/6 8/13 8/20 Field Capacity

14 So we ended up with soil moisture data demonstrating cold desert bioretention hydrology M 3 water /M 3 soil Drip rhus 25 cm Drip rhus 50cm /14 5/21 5/28 6/4 6/11 6/18 6/25 7/2 7/9 7/16 7/23 7/30 8/6 8/13 8/20

15 So we ended up with soil moisture data demonstrating cold desert bioretention hydrology M 3 water /M 3 soil Drip rhus 25 cm Bucket rhus 25cm Olla rhus 25cm /14 5/19 5/24 5/29 6/3 6/8 6/13 6/18 6/23 6/28 7/3 7/8 7/13 7/18 7/23 7/28 8/2 8/7 8/12 8/17

16 So we ended up with soil moisture data demonstrating cold desert bioretention hydrology M 3 water /M 3 soil Drip rhus 50cm Bucket rhus 50cm Olla Rhus 50cm /14 5/24 6/3 6/13 6/23 7/3 7/13 7/23 8/2 8/12

17 So what does it all mean? 1. Remember the 1:1 drainage to garden ratio? VS Example Calculation: 1 acre x 300% average precipitation of 12 = 3 acre feet 10 acres x 50% average precipitation of 12 = 5 acre feet

18 So what does it all mean? 1. Remember the 1:1 drainage to garden ratio? 2. It started to rain 300% 200% 100% 0% 100% October November December January February March April May June July August Drip Mahogany 25 cm 0.2 Drip Mahogany 50 cm 5/14 5/21 5/28 6/4 6/11 6/18 6/25 7/2 7/9 7/16 7/23 7/30 8/6 8/13 8/20 M 3 water /M 3 soil

19 So what does it all mean? 1. Remember the 1:1 drainage to garden ratio? 2. It started to rain 3. Soils never approached wilting point Olla rhus 25cm Olla Rhus 50cm M 3 water /M 3 soil Field Capacity /13 7/20 7/27 8/3 8/10 8/17

20 So what does it all mean? 300% 100% 100% October Novem Decem January February March April May June July August

21 So what does it all mean? If planting bioretention in a cold desert with native shrubs in the FALL, then irrigation is not needed AT ALL This concept is strongly supported by wild land restoration and plant physiology literature

22 So what does it all mean? The ever-evolving plant recommendations for use in bioretention in cold deserts Species name Common Name Form Rooting Pattern Schizachyrium scoparium Little bluestem Bunchgrass Extensive Bouteloua gracilis Blue gramma Bunchgrass Extensive Sorghastrum nutans Indiangrass Bunchgrass Extensive Pascopyrum smithii Western Wheat Grass Bunchgrass Extensive Pseudoroegneria spicata Bluebunch Wheat Grass Bunchgrass Extensive Rosa woodsii Wood rose Shrub Extensive Rhus Aromatica Fragrant sumac Shrub Extensive Fallugia paradoxa Apache plume Shrub Extensive Chrysothamnus nauseosus Rubber rabbitbrush Shrub Deep Juniperus osteosperma Utah Juniper Tree E and D Cercocarpus ledifolius Curly mahogany Tree Deep Artemisia tridentata Sagebrush Shrub E and D Cercocarpus montanus Mountain mahogany Shrub E and D Eschscholzia californica California Poppy Flower E and D Epilobium angustifolium Fireweed Flower Extensive Tulipia sp. Tulips Flower Bulb Delphinium bicolor Low larkspur Flower Extensive Survived last year w/out irrigation in full sun Survived in both sites Survived last year w/out irrigation in limited sun Not tested

23 Thank You!

24 Thank You! Dr. Christine Pomeroy Dr. Steve Burian Dr. Paul Tikalsky Whitney Williams, U of U Office of Sustainability WEF AWRA Student groups Zach Steel, Pascaline Loquort, & Jen Stephen

25 Contact Info Dasch Houdeshel Dr. Christine Pomeroy, PhD, P.E.