2.7-Acre Atascadero Homestead

~ Level 1 Site Assessment ~

Level 1 – Site Assessment

Location: Atascadero, CA

Project: 7th Generation Design was invited to conduct an assessment of a 2.7-acre property located in Atascadero, CA. The landowners communicated a desire to rehabilitate a degraded plot of land and develop a climate-appropriate regenerative homestead with the following major goals:

  • Create a safe and healthy place to live and for family to gather,
  • Grow as much of their own food as possible,
  • Rehabilitate a degraded landscape into a lush example of climate-appropriate living,
  • Adopt and care for rescue livestock animals.

Existing Conditions:

  • The property is located on the toe of a secondary ridge just above the primary valley bottom below. The secondary ridge runs from the west to the northeast. The majority of the property acreage lies below the leveled pad where the Main Residence is located, consisting of slopes that range from 13% – 70% grade.
  • Temperatures with typical highs between 60-95℉ and lows between 35-55℉, with an estimated  800-1200 chilling hours (<45℉) per year.
Colorized elevation model and 10ft contour lines.
  • Average rainfall of 17.53 inches per year, with approximately 1.5 million gallons of water landing on the property per average rain year, with an additional estimated 0.5 million gallons running onto the property from uphill neighboring properties.
  • High solar exposure, with an average solar insolation level of 6.23 kWh/m2/day (compared to that of Death Valley, CA at 6.4 kWh/m2/day, and Fairbanks, AK at 3.1 kWh/m2/day).
  • Monthly average winds range from 0.2 – 0.9 mph, blowing predominantly from the northwest to the southeast during the spring and summer and from the northeast to the southwest during the fall and winter.
  • Fine clay-loam soils with low fertility, low permeability, moderate to high runoff potential, and 16-40” effective rooting depth.
Base map of existing conditions
Influencing sector map
Zones of use map

The following issues were identified in the assessment which will pose significant ongoing challenges to the landowners in meeting their goals unless rectified:

  • High cost of domestic and irrigation water. Domestic and irrigation water for the property is sourced from Atascadero Municipal Water District and currently billed in the residential tiers at $.00270 – $0.00810 per gallon depending on monthly usage levels.
  • High amount of surface runoff, with one major erosion area. Of the approximately 1.95 million gallons of rainwater that lands on and runs onto the property during an average rain year, an estimated 700,000 – 1,200,000 gallons (35% – 66%) is lost from the property as runoff. At the Atascadero Mutual Water Company’s current equivalent residential usage tier rate of $0.00610/gallon, this equates to an average of $4,300 – $7,300 worth of water that is being lost annually. A portion of the runoff is being directed onto the neighbors property to the south where severe erosion is developing. This run-off is also a drain on soil fertility, as it removes the organic matter and fine soil particles that are the backbone of a healthy, well-structured soil with every passing year
  • Lack of perennial vegetative cover on the pastures, which poses several issues:
    • Lack of vegetative cover is significantly contributing to the runoff issues noted above, which guarantees decreasing soil fertility with each passing year.  Living root mass is the most effective means of infiltrating water into the soil where it can be productively used by plant roots and soil biota.
    • Soil compaction due to loss of soil structure, and thus decreasing water infiltration and water storage capacity. The pore spaces that are created in a healthy, living soil from plant roots, the exudates they produce, and the soil biology they help to protect and sustain are diminished or gone entirely in some places.
Aerial photograph showing the largely denuded and compacted slopes. Of the approximately 2 million gallons of rainwater that lands on and runs onto the property during an average rain year, an estimated 700,000 – 1,200,000 gallons (35% – 66%) is lost from the property as runoff.

Initial considerations recommended for further investigation in a whole-site design process included:

  • Installation of a site-wide passive water harvesting and drainage system. Through the use of passive water harvesting elements such as infiltration basins, swales, and boomerangs at strategic points and the integration of armored drainage points from overflow spillways, the estimated 0.7 – 1.2 million gallons of erosive surface runoff shed by the property during an average rain year can be spread out along the ridge and infiltrated into the soils to nourish downslope perennial shade/fodder/habitat living systems.
  • Establishing cover over all bare soils in the pastures by revegetating using all seven layers of a functional forest ecosystem. To create the most resilient, self-sustaining ecology and revegetation efforts should leverage the patterns found in natural mixed forest and savannah type ecosystems. Planting a multi-layered assemblage of multi-functional species will help to 1) “grow shade” and thus reduce soil surface temperatures, evaporative loss, the highly erosive impact of unimpeded rain on bare soil, and create a more hospitable soil surface temperature for plant feeder roots, 2) jump-start the soil fertility recovery process, and 3) grow useful fodder and food for livestock and humans alike.
  • Intensive live-stock management involving high-frequency, short-duration animal rotations followed by adequate rest periods to steward vegetative recovery. The landscape is currently showing the cumulative effects of years of conventional fire risk mitigation practices combined with overgrazing and constant pressure from livestock. Animals have a very important role to play in rehabilitating the water and mineral cycle in the soil, their manure being one of the key ways to build living soil even during the long, dry summers characteristic of this region. In order to make the presence of animals an asset to the overall land rehabilitation goals, their access to and time spent on any given piece of ground will have to be managed intentionally.