Rehydrating Toro Creek with Sustainable Agriculture: Traceland Farm Demonstration Project

Objective 1: Water management accounting

• Description:
  • Earthworks have been delayed until at least April 2023 due to local flooding and inadequate work conditions. Some of the terms of the subsequent objectives have been postponed until necessary grading takes place.
  • The water budget for Traceland Ranch was further developed based on existing information. Observations of storm events were taken into consideration to inform design sizing while site-specific infiltration rates have been delayed until grading is executed.  
  • We assessed the consumptive water use of the Trace Farm to reduce the water footprint and off-set pumping from the agricultural riparian well that is hydrologically connected to stream flows in mainstem Toro Creek. Water consumption was measured according to irrigated agriculture and time of use per linear foot from April 1^st to July 31^st (see Table 3). There are 7,000 acres of the Toro creek watershed located up stream of the Traceland agricultural well, dozens of land holders with riparian rights and hydrologically connected wells and large variability of annual precipitation amounts. Meanwhile, the size of the watershed of this rehydration project is only roughly 35 acres, about half of which drains upstream of the well and the rest drains below it. After the consideration with technical advisors of these facts, we determined that measuring the Ag well connectivity to Toro Creek is beyond the scope of this project’s goals. Attention will be focused on measurement of infiltration on terrace / 100-year floodplain drainage via test wells and piezometers. 
  • A conceptual framework was developed for water conservation, streamflow enhancement, and benefits to riparian floodplain habitat according to the principles of keyline farming design.  
  • Delayed: Investigate how oak woodlands / dry farmed perennial tree crop species contribute to and use groundwater and its effects on Toro creek streamflow.
  • The efficacy of the rainstorm run-off catchment system was not yet measured. Data will later be incorporated into overall water footprint accounting of Traceland agricultural operations. Steps have been taken to work with Cal Poly SLO professor PhD Bwalya Malama, Associate Professor of Groundwater and Soil Biophysics to sample the subsurface, characterize the sediment hydraulically, install piezometers, and perform some pilot studies on aquifer-stream interactions, managed aquifer recharge potential, and long-term monitoring of the hydrologic system. We are currently working on finding funding options for this work in partnership with Creek Lands Conservation (CLC).
  • Delayed: Inspect catchments after rain events and determine approximate water volume captured (Repeat process for the first 3-5 years until earthworks stabilize from reforestation)
  • Delayed: Determine water infiltration/evaporation rate
  • The long term (10 years) Toro creek flow measurement analysis efforts were first recorded at Traceland by the California Conservation Corps (CCC) in 2020 and their latest efforts will be incorporated accordingly.
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• Materials: Measuring device oriented vertically in recharge basins to measure water level, piezometers, test wells, evaporation rates
• Methods: Simple arithmetic to determine water captured and incorporation of appropriate evaporation and infiltration rates to reach sum. 

Objective 2: Expand agricultural operations onto valuable Class 1 alluvial soil agricultural land and simultaneously restore native habitat across approximately 12.5 acres, 

• Description: 
  • Earthworks have been delayed until at least April 2023 due to local flooding and inadequate work conditions. Some of the terms of the subsequent objectives have been postponed until necessary grading takes place.
  • Delayed: Integrate traditional ecological knowledge/approaches where feasible (i.e. prescribed burns to manage leaf duff, acorn weevils and understory vegetation)
  • Delayed: Chart wildlife species (terrestrial and aquatic) response to restored habitat via biological baseline and monitoring of changes.
    • Baseline started in summer of 2019 until present containing 118 observations on site, 76 of which are research grade species.
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    •       Figure 1: iNaturalist Observations
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    • Figure 2: Example 1 Observations                     Figure 3: Example 2 Observations
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  • Based on advice from the International Oak Society and the CCC we decided to sow our own local and climate adapted seeds and nuts and to use specialized air pruning tree pots. Change in sourcing is better quality than local nursery stock and under original budgeting cost. Plants have been germinated and are developing well. Establishment in the field, monitoring and maintenance will take place after delayed earthworks to ensure survival.
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  • Figure 4: Black Walnut Tray                                   Figure 5: Coast Live Oak Tray                            Figure 6: Island Oak & Q. species
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• Item	Quantity	Cost
  3” x 8” air pruning pot	200	139.80
  3” x 8” pot container	8	71.92
  4” x 14”  air pruning pot	318	329.88
  4” x 14” pot container	23	265.77
  5” Plug Trays	2	116.60
  Tax + Shipping		332.30
  Total		$990.95

   Table 1: Nursery Pot Costs

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• Item	Quantity	Cost
  Kellogg Potting Soil (PS)	3	35.85
  Kellogg (PS) + Peat	5+1	97.81
  Total		$133.66

  Table 2: Potting Soil Costs 

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• Developed plant palette based on bioregional ecosystem mimicry: oaks, black/persian walnut, salal, huckleberry, currant, elderberry, grape, service berry, (timber, food), and found an estimate of mature oak orchard acorn production at 3.1 – 7.7 metric tons per hectare according to the book The Carbon Farming Solution, written by Eric Toensmeier, published in 2016.
• We incorporated the appropriate sizing/spacing for conservation plantings, and agro-eco rows into the design (with alleys between trees leaving plenty of space for more intensive ag and about 30 years to do it before shaded out by mature trees)
• Conceptualized and finalized planting plan to establish native-dominant plant communities on terrace/100-year floodplain and adjacent hills to enhance botanical biodiversity and increase wildlife habitat complexity. The plan integrates productive agricultural ecosystems (e.g. edible landscape) that emphasize the diversity and functions of natural ecosystems and integrate soil health elements such as mulch application, monitoring of the reintroduction of natural mycorrhizal mycelium, and soil sampling to evaluate soil minerals
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    • Figure 7: Mature Design                                        Figure 8: Spacing                                                  Figure 9: Plant Palette
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      • Figure 10: Conservation Row                               Figure 11: Agro Eco Row 1                         Figure 12: Agro Eco Row 2
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• Riparian functions that will be enhanced or restored: Reconnecting the lowest areas in the landscape that contain the most ground water to higher elevations will bring water nearer to the surface and make it more available for plants. Measurable ecological benefits will follow the grading of the terrace and reintroduction of phreatophytes such as Quercus species. Natural storm water capture on the 100-year flood plain promotes productive and diverse plant communities; will disperse nutrient-rich organic matter and dissolved nutrients; will emit water later in the drought to enhance survivability of organisms within the riparian zone; and will promote species diversity and biological productivity across a broader range of habitat types. According to the technical knowledge of Brad Lancaster in his book Rainwater Harvesting for Drylands and Beyond we have chosen the slow, spread and sink method to direct groundwater into the riparian zone and support ecosystem health.
• Materials: iNaturalist project, Graphical Soil Analysis Report
• Methods: Monitor wildlife populations and upload new species onto iNaturalist as habitat develops. 
  • Soil sampling with A&L Western Ag Lab

Objective 3: Reduce soil erosion and stream bank collapse 0.5 miles of Toro Creek 

• Description
  • Earthworks have been delayed until at least April 2023 due to local flooding and inadequate work conditions. Some of the terms of the subsequent objectives have been postponed until necessary grading takes place.
  • Two main erosion gullies from the 100-year terrace ending in mainstream Toro creek have been located and assessed. An armored energy dissipation bowl was developed and implemented for the lowest of the two erosion gullies. The second gully will be addressed once rehydration grading takes place. This demonstration project is intended to be a model with tangible solutions to landowner level erosion. This can then be adapted within the entirety of the watershed and in others to collectively reduce peak run-off flash flooding and subsequent creek bank erosion and infrastructure damage. The assessment of mainstem Toro creek is beyond the scope of this project.
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  • Figure 13: Energy Dispersion Bowl  (EDB)                  Figure 14: EDB during rain 
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• Materials: Camera and 100' measuring tape
• Methods: Monitor several points systematically along the creek bank and chart evolution. 

Objective 4: Capture > 500k gal stormwater run-off 

• Description: 
  • Earthworks have been delayed until at least April 2023 due to local flooding and inadequate work conditions. Some of the terms of the subsequent objectives have been postponed until necessary grading takes place.
  • Delayed: Conceptual in line berm, swales, and collection recharge basins design to shovel-ready plans (i.e., confirm sizing, layout). A conceptual and final level plan and details to restore natural hydrological processes on terrace/100-year flood plain and adjoining hills by slowing, spreading, and sinking stormwater runoff in rain gardens, bioswales, or other landforms designed to optimize agro-ecological health, enhance botanical biodiversity, and reduce land degradation and erosion;
• Materials
• Methods

Objective 5: Capture and bio sequester atmospheric CO2 (planting 143 trees) (2,400lbs co2 per oak)

• Description:
  • Earthworks have been delayed until at least April 2023 due to local flooding and inadequate work conditions. Some of the terms of the subsequent objectives have been postponed until necessary grading takes place.
  • The carbon footprint of the project’s activities was accounted for to neutralize its emissions via planting. The long-range carbon accounting has been postponed until grading takes place and trees are selected and established. Based on CUFR calculations, this project will reach carbon neutrality in 11.5 years.
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  • Delayed: Includes future outreach to education/ extension to ensure the appropriate metrics are being looked at and opportunities are maximized to study and integrate carbon accounting and footprint understanding in order to replicate on other farms.    

• Materials: Measuring tape, CUFR Tree Carbon Calculator.    
• Methods: Take annual measurements of tree DBH and determine CO2 biosequestration. 
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• Figure 15: CUFR Calculator                                 Figure 16: Carbon Capture

Objective 6: Research and develop acorn food production as a high-value, gluten-free, delicious flour and foodstuff.

• Description:
  • Initial contacts have been made with a Portuguese oak dehesa agroecological farm called Freixo do Meio commercializing acorn foods as well as other woodland products. A realistic first commercial harvest was determined to be within 15-25 years of initial planting. A literary review has been conducted to conceptualize value-added acorn products and harvesting methods to improve efficiency of production. Acorn recipes have been developed from local species to target flavor profiles and culinary opportunities.
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• Figure 17: Acorn Recipe Experiments

• Materials: 5 Gallon Bucket, Nut Wizard, Scale
• Methods: Cut grass under selected trees and gather acorns between November and February. Weigh gathered acorns and chart over time.