Same area -- after mitigation and ready for seeding
On the topic of land, there’s been the “what we wanna do” according to our own values and the “what we gotta do” according to Build Green NM standards. Fortunately the “wanna” and the “gotta” are frequently the same.
Finding some land that met our needs was the first big step. Key was a good southern exposure for passive solar and solar panels. Also important was a piece of land that “hugged” us! Ok, I know that sounds strange, but there you are.
The land we bought is sloped. While not steeply, it is sloped enough that to build a one-story home would require cutting, scraping and flattening a large footprint with the requisite excavation leaving soil and rock to dispose of. Both of us preferred not to have a house on the edge of a hillside. Particularly we wanted to minimize the disturbance of the lot, to avoid breaking down the natural structure of the land and its vegetation. So we shifted the house design from a single story to a story and a half, placing the guest room, my office and bath on the lower level, at about half the square foot of the upper level. This shrunk the house footprint and so minimized the disturbance, allowing us to build into the structure of the slope. What was interesting was that we earned BGNM points for a multi-story design – smaller footprint, fewer materials to build. Side note: Since we plan to grow old in this house, and we now have to contend with stairs, we planned structure support for a glide-chair into the framing design; hopefully we won’t need that for some years!
Minimal disturbance has become our mantra – to limit how much surface is broken, how much vegetation is removed, how much impermeable surface is added. So some of the challenges have been:
· Cutting the driveway to the house so that it follows the shape of the land. Cutting it straight down would set us up for serious erosion and water problems, so the driveway follows the slope and then curves around to the front of the house.
· Identifying trees that we wanted to preserve. We walked the land with the builder, discussing slope and cuts and trees and the overall idea of “not one inch more than necessary.” And then came the fires and learning about defensible space. We have trimmed up more and taken out more shrubs and small trees than the absolute minimum and will wait to see how that will square with BGNM requirements.
· Keeping the disturbance of the surface to a minimum. We attempted to stack the utilities – electricity, water and land-line telephone – into the smallest possible trench in order to minimize the trenching and displaced soil. This effort didn’t work out as well for several reasons. The other area of disturbance that was difficult to manage was cutting in the septic system including the drain fields. I’ll talk about lessons learned on these issues in a minute.
· Disposing of the excavated “load” of soil and rock. We were fortunate to be able to dispose of over half of the soil and rock excavated from the house, the utility trench and the septic field on the property. The property is cut by a dirt track which has been there a long time, used by walkers traversing our land and the adjoining land, and by dirt bikes and atv’s from the large open land next to us. We prefer not to leave access to the bikes and atv’s; that’s probably an East Coast thing (after all Robert Frost was an Easterner, too). Some of the load was piled across the track at the entry point used by bikes and atv’s and will eventually be softened with rock and plantings. The rest was spread along the track then compacted, filling holes and overall raising the level of the earth, and finally covered with straw to await seeding. Anyway, using the load in these ways coincided with BGNM because there are guidelines in BGNM about how much fill can be exported.
Remediation or mitigation is the other mantra we’ve learned. Where the soil surface has been disturbed for trenching or septic, we are taking steps to mitigate the damage.
· Consulting with experts in water management and restoration. More than just to check off the right boxes in the BGNM chapter on lot design, preparation and development, this is a conscious effort on our part to put the land back the way it was. Van Clothier of Stream Dynamics met with us to talk about mitigating the water flows on the driveway and preventing run-off and erosion on the land where the trench was cut down the slope. We also talked with an expert in restoration of grasslands who made recommendations for types of native grass seed and how to spread it. But it was my idea to add in the native, drought-resistant wildflower seed.
Lessons learned. Some of our lessons have been more painful; others have been so completely obvious, at least after they were pointed out; and one or two have been more expensive than anticipated.
· Keeping the surface disturbance to a minimum met with unexpected hurdles such as more rock than anticipated or a telephone engineer who insisted on a wider trench than planned to provide for an excess (so it seems) of separation. Both of these meant more equipment movement on the ground; more trenching and excavating of material; and therefore more material to be disposed of.
· Creating a common idea of what “minimum disturbance” means takes a lot of talking and checking-in. So while everyone believed they were doing the right thing, especially in filling and spreading and moving the load, it turned out that we all had a different idea of what the “right thing” looked like. For example, it would have helped if we had thought to have an agreement about talking first when the unexpected arose and there was more rock and soil to move and spread.
· Restoring the disturbed ground so that it looks like the neighboring ground that wasn’t disturbed. This should have been so obvious. But it took two consultants to help us see how to do it. Don’t rake it clean. Leave it a little rough, with smaller bits of fractured rock in the mix. Take all those round surface rocks that were moved out of the way of the equipment and move them back on the disturbed surface. When the bare ground looks just like the grassy ground except without grass, it’s ready to seed! Those rocks and the roughness are perfect for slowing and sheeting the water, preventing erosion and giving grass seeds the little spaces they need to stick and germinate.
The land heals itself if given a chance. Collectively, we’ve seen this after the big fires; if we leave the land alone, it will heal most effectively. So we’re learning this on our land. As devastated as it looked – and compared to most construction, it wasn’t very devastated at all – it will again look and feel like it did before the first mechanical broke the surface. Even without putting any seed down, there are sprigs of green coming up. Now that the rains are starting, we can spread among the native rock the NM blue gramma and sideoat gramma, mixed of course with those wildflower seeds and see what happens.
