Experimental Design and Methods
The Landscape Lab consists of 9 stormwater bioretention basins and surrounding landscaping.
Basins 1-8 capture stormwater runoff from the Williams Building and the Myriad Building, their associated parking structures, and landscaping. Basin 9 captures stormwater runoff from about .21 acres of paved roadway via a curb cut.The main 8 basins are paired such that an upper basin receives the stormwater first, then the second basin serves to capture any overflow if the capacity of the upper basin is exceeded. There is a final overflow to the storm drain system at the bottom of the second basin in each pair.
The pairs of bioretention basins were designed with two replicated planting treatments, “native” and “optimized”. The native treatment was selected based on the idea that native ecosystems will perform best in local conditions. Thus the plants chosen are all native to the Wasatch Front (as referenced in Arnow 1977 Flora of the Central Wasatch Front). In contrast, the optimized treatment removed the restriction on locally native plants and permitted designers to use plants that may be horticultural varieties or non-native but are generally thought by local professionals to be high-performing in a water conservation landscape.
|“Native” plant mix|
|Scientific Name||Common Name|
|Artemisia tridentata||Big sagebrush|
|Mahonia repens||Creeping Oregon grape|
|Rosa woodsii||Wood rose|
|Rhus typhina||Tiger eyes sumac|
|Fescue idahoensis||Idaho fescue grass|
|Deschampsia cespitosa||Tufted hair grass|
|Sphaeralcea coccinea||Scarlet globemallow|
|Penstemon stricta||Rocky Mountain Penstemon|
|Arctostaphylos uva ursi||Kinnikinnick|
|“Optimized” plant mix|
|Scientific Name||Common Name|
|Schizachyrium scoparium “Blaze”||Little bluestem grass|
|Prunus besseyi “Pawnee Buttes”||Western sand cherry|
|Rhus typhina “Bailtiger” TIGER||Tiger eyes sumac|
|Geranium sanguineum||Bloody cranesbill|
|Bouteloua gracilis||Blue grama grass|
|Mahonia aquifolium “compacta”||Dwarf Oregon grape|
|Echinacia purpurea “sunset”||Sunset coneflower|
|Aquilegia caerulea “Rocky Mountain”||Rocky Mountain blue columbine|
|Philadelphus microphyllus||Littleleaf mock orange|
All bioswales were unlined. The bottom of the swale consisted of exposed native soil and rock, with a 12” layer of planting soil in the bottom of the swale. The planting soils consisted of the native soil from the site with amendments. Three composite samples (three subsamples each) were taken from three large piles of soil on-site during the excavation phase and sent to the soils testing lab at Brigham Young University for texture, contaminant, and nutrient analysis.
Based on the initial lab tests, the soils were amended with compost to bring the organic matter content to 5% in the native treatment and to 10% in the optimized treatment. Both treatments were also amended with equal proportions of wood chips generated by tree thinning on-site during the project. For the optimized treatment only, additional NPK fertilizer was added as per the lab recommendations for drought-tolerant shrubs and trees.
The sides of the bioretention swales and the areas between swales are covered with weed control fabric and were planted in 6” of native topsoil plus 2” of compost mixed in. The entire site was covered with 3” of rock mulch. Boulders came from Mountain Valley Stone (Peoa, UT).
The sides of the bioretention swales and the areas between swales are covered with weed control fabric and were planted in 6” of native topsoil plus 2” of compost mixed in. The entire site is covered with 3” of rock mulch. Drip irrigation is installed throughout the landscape, with individually-controlled zones.
Instrumentation and Data Collection
Each basin contains one soil moisture sensor pit near the inflow to the swale. Additionally, swales that receive direct storm water input (the first swale in each pair) have a second soil moisture sensor pit near the outflow of the swale. Each pit contains soil moisture sensors at three depths: 20cm, 50cm, and 80cm. Soil moisture sensors are METER Teros 11.
Flow sensors (not installed yet): stormwater flow into each basin will be calculated by measuring water depth in each storm drain with Flowline DX10 Echopod sensors coupled with Manning’s equation to calculate flow.
The Landscape Lab is part of the Wasatch Environmental Observatory (WEO), and it takes advantage of existing instrumentation and data collection along Red Butte Creek. Data streams from the Landscape Lab will be part of the WEO data collection available on Hydroshare.
Automated, in-situ measurements:
- Weather station data at the Green Infrastructure Research Facility (GIRF)
- Cottam’s Grove (upstream of LL) WEO site: RBC stream flow & chemistry
- Foothill Drive (downstream of LL) WEO site: RBC stream flow & chemistry
- Connor Road WEO site storm drain flow- receives input from LL overflow pipes as well as other locations in Research Park
Data for each of these sites is updated daily and available on Hydroshare.
Locations: see map below. We measure flow/water quality of RBC upstream and downstream of the LL.
Parameters measured: Storm drain sites measure flow. Aquatic sites measure flow and water quality parameters/chemistry, including temperature, conductivity, dissolved oxygen, turbidity, and pH. Additionally fluorescent dissolved organic matter (fDOM), Blue-green algae, and chlorophyll at Foothill Dr. aquatic site only (downstream of LL).
More info on data streams to come as we get them set up!