Pretty, Hardy Weed

After considering problems in critical areas, the next logical runoff concern is that from slopes in general - the steeper the slope, the greater the concern. Slopes not only erode easily, but they also often carry water away too quickly for it to infiltrate the soil. A slope of sandy soil can wash out very quickly and sandy soils are the norm here in Calvert County.

Such was the case at my church where a pocket pond filled up with sand that eroded from its banks before vegetation could stabilize the slopes. The county inspectors finally caught up to us and put us on notice to fix it. The repair plan involves filling up woven bags with the sandy deposits and stacking them on the eroded banks. In short order, we need to also establish better vegetation cover to avoid future problems. Here might be a good place to show how biochar and compost can allow things to grow in difficult conditions.

Not many plants want to grow on sandy slopes, but cypress spurge is one that I found recommended for that situation. I will be on the lookout for it on the roadside as I go about in the next few weeks. If it's as invasive as it's reputed to be, the plant should be pretty easy to find. In fact, I believe I noticed some recently, but wasn't in the market for it at the time. Though normally considered invasive, cypress spurge is the only plant for poor soil among ten recommended by the University of Maryland extension for stabilizing slopes.

Charcoalkultur

Infiltration berms belong at the public works level, but a comparable practice for us masses is hugelkultur. I attended a talk last year at the Mother Earth News fair comparing biochar to hugelkultur and discovered that hugelkultur is generally easier and less chancy than making and applying biochar. Yet, a hugelkultur bed will not be as long-lived as one with a load of biochar.

Hugelkultur is the practice of piling soil and organic material on top of a bunch of logs and sticks to form a mound (mainly on contour) which can capture runoff in order to grow plants like a super high raised bed. +paul wheaton published a DVD about it and  +Sepp Holzer put some good instructions on Paul's richsoil website.

I've been using hugelkultur to augment swales in order to reduce erosion on the back slope of my property. My previous post about infiltration berms brought me to consider hugelkultur not as an alternative to biochar, but as another opportunity to put biochar to good use. Filling the gaps with biochar (or some percentage thereof) while building a hugelkultur bed is one way. Biochar could also be applied in areas where there is a need for extra moisture.

Such was the case with my wife's hydrangea which she wanted planted in a sloped area that normally would not stay moist enough for this plant. Yet, there is a roof downspout nearby which spills out onto the slope (via a splash plate) once the rain barrel fills up. I built a quasi-hugelkultur bed to direct the overflow to the hydrangea and loaded the outlet with unground biochar in order to slow the flow of water and hold it close to the plant.

There is enough of a dam behind the biochar to keep it from being washed away. Over time the biochar will break down into small particles and leach into the soil where it can do even more good.

I can see using biochar in a similar fashion on the uphill toe of a hugelkultur bed in order to reduce the tendency of the toe to erode where runoff sheetflow meets the mound. For highly steep slopes (> 25%), a deep swale on the uphill side of the hugelkultur mound containing some percentage of biochar could serve the same purpose.

Swales are an approved ESD practice in the Maryland Stormwater Manual. Hugelkultur beds aren't, but there may be enough latitude in the specs and descriptions that it would fit without requesting special approval. Beyond these practices, terracing is the next step for reducing runoff on steep slopes. For that, heavy equipment is needed, so it's better in most cases to think in terms of swales and mounds.

Getting Cred to Help the Watershed

Rain barrels are one of many changes you can make to your property for stormwater management. BayWise certification process and reading +Michael Judd's book, Edible Landscaping, I hadn't realized how important erosion control is to gardening. The organic layer of a garden is the first to wash away, so getting control of how rainwater flows is a must in setting up any planting area. The main things are to reduce the velocity of runoff and to capture nutrients before they escape.

The University of Maryland Extension notes many other features which I have incorporated into my hilly property, such as rain gardens, conservation landscaping, swales, fertilizer reduction, a pet waste station, and tree planting. Before going through Maryland's

Stormwater management is not the most tantalizing task, even less so when it requires many hands. That is why, in setting up a curriculum for the Watershed Stewards Academy, the University included lessons on educating and motivating groups to take action. County ordinances, such as Calvert's offer a negative incentive to meeting minimum standards, i.e. do it, or we will do it for you (on your dime). Right now, my church faces a choice between taking the initiative or the risk of getting negatively incentivized to remediate the erosion that has occurred over the past several years into their detention pond.

A motivator of those who seek certification through the university extension as a Master Watershed Steward Volunteer, or Master Naturalist Volunteer, or (in my case) Master Gardener Volunteer is the scale at which you can hope to have an impact.  It's not just on your own property, but in many parts of the locale.

Water is every bit as critical to our future as food, and even more urgent. Expanding local applications of biochar and mycorestoration as well as the exigent need at my church could draw me into making the jump to the Watershed Steward program, ne: Master Gardener. There is only a little while to decide, since the application deadline for the next class is April 22. There are information sessions tonight (March 23) and next Thursday for anyone interested.