A Passable Stream

I have pleasant memories of the street near my grandfather's southern California ranch bordered by a three-foot wide concrete lined drainage ditch. Though I now live in a residential area that borrows its name from western ranch culture, we don't do gutters here much. Instead, we have some stormwater management ponds, lots of woods, and drainage ditches that are pretty much out of sight and mind. Fifty years has taken a toll on many of these ditches, so it may be time to restore them.

The restoration work that would qualify as a Best Management Practice (BMP) is much more than I had envisioned. Whereas my first thought was to simply use several wattles to filter runoff before it reaches the lake, Maryland prefers that long runs be totally retrofitted. An example that bears a strong similarity to one stormwater channel near my land is shown on pg. 60 of this presentation on the topic of Step Pool Storm Conveyances and copied here:

The step pools in the lower photo were created by emplacement of very large rocks and an equal amount of riprap in the stream bed. Underneath is a substantial amount of woodchips and sand mixed together to promote drainage. The banks have been reformed into a wider floodplain, but the stream elevation is unchanged. The engineering behind it all is pretty intense, so taking this on would be a real challenge for me.

Getting someone to fund all this might be a problem, but it is worth taking some time to grind through some calculations to see if the nutrient loading on Lake Lariat (which carries over to the Chesapeake Bay to some degree) could be reduced enough to earn nutrient trading credits. Who knows, the restoration might even pay for itself (besides doing nice things for the neighborhood and the lake). Fortunately, the HOA has equipment that might allow us to do it all in-house.

Wattles could still be the first step. They would be located near the outfall where the channel is shallow. The restoration work could take place upstream of the wattles, which would be useful for a few years and help reduce sediment spilling into the lake during restoration.

Git 'er Done

By Mark Rain

To get them all done in time to avert ecological armageddon, the thirteen prescriptions for healing the planet offered by the concerned scientists who signed the updated warning to the world would require coordination at the highest level conceivable. Coordinating implies a grasp of the larger system effects of any particular activity, prioritizing some over others as needed for the good of the whole. Though strategic coordination is sorely lacking on the environmental front, focused efforts may still help, if not just to allow more time for wiser leadership to ascend.

One of the ominous trends shown in the report is the 75% increase since 1992 in the number of dead zones in the oceans and estuaries.  The supplemental report's description reads,

Coastal dead zones which are mainly caused by fertilizer runoff and fossil-fuel use, are killing large swaths of marine life. Dead zones with hypoxic, oxygen-depleted waters, are a significant stressor on marine systems and identified locations have dramatically increased since the 1960s, with more than 600 systems affected by 2010.

The trend has been nearly linear for the past 50 years, in which about 12 additional aquatic zones have died each year. One of these is the upper Chesapeake Bay where I live. Dead zones are a degenerated condition of algae blooms that rampantly feed on phosphorus and nitrogen, overpopulate, and die, with the consequent breakdown of algal biomass starving the surrounding waters of oxygen and releasing chemical toxins. In 2016, toxins from blue-green algae were found in one-third of lakes and reservoirs in the U.S. One of those was the 90-acre lake in my neighborhood.

Agriculture is blamed for much of the nutrient runoff in the developed world. Fossil-fuel use is also implicated in the report as a cause of dead zones. In less developed areas, sewage is the main contributor. In that respect, my neighborhood belongs to the less developed category. With 4,500+ homes on 6 square miles of hilly land, the number of septic systems overloads the watershed.

While hilly land promotes more runoff, it may also be key to a solution. Most of the runoff does not flow directly into the lake, but into ravines that eventually empty into the lake. My idea to lessen the amount of nutrients in the lake is to install filtration wattles not along the entire lakefront, but one wattle per ravine at the endpoint of contributing septic drainage. Using a mixture of biochar and ablated clays, zeolites, vermiculite, and possibly peat, wood chips, mushroom spawn, or compost, the wattle can be imbedded at the surface of the streambed. This would be done initially at several of the largest ravines with test filters which could be used to measure phosphorus buildup after a year. The ravines with the largest amounts of phosphorus in their test filters would then receive a larger number of wattles to capture the major nutrient flows. I am hoping to get a grant to execute this plan, possibly teaming with a local biologist and academia as an innovative research project. Without funding, I could probably perform a limited version of the plan.

For those whose decisions lack global reach, thinking globally and acting locally at least gains you some cred, raises awareness, encourages replication, and offers the consolation of confronting the world's problems, though they may seem to mount. As one's credibility grows, one can possibly take a leadership role which could involve less hands-on implementation and more coordinating. I am not knowledgeable enough to adjudge priorities between the thirteen global solutions recommended by the thousands of scientists who issued the warning, but that doesn't stop me from taking action at a local level.

The Solution to Pollution is Economic Revolution

It may have escaped most people's notice that availability of the earth's resources has been swiftly declining for decades. This will soon be reflected in a declining rate of goods available to the average world citizen, including food. Widespread hunger will be a faithful witness that we lack the basic necessities to sustain a growing world population. Those of seared conscience will begin to take notice when they sense it in their gut, if not in the food line.

This predicament simplifies decision-making considerably. When decisions deal with feeding a starving population in the interest of the common good, choices that improve food production and distribution should receive highest consideration. Problems that weren't formerly seen in those terms are brought into stark relief when recast in the context of famine.

Many issues could be boiled down to how well the possible solutions improve food availability, but one salient example in my neck of the woods is the health of the Chesapeake Bay. There are many eco-services that a vibrant Chesapeake Bay watershed offers to the economy (most currently valued more than food), but food production alone is more than enough to justify government expenditures toward restoring the watershed.

A 2014 peer-reviewed study for the Chesapeake Bay Foundation determined that the natural capital of the watershed offers a high economic return on our restoration dollars spent. Of the billions of dollars of benefits we reap from this unique ecosystem, only about 10% comes in the form of food production, e.g. seafood and agriculture. Nevertheless, a 10% increase in baseline food production, which could be expected from cleaning up the bay, is of sufficient economic value alone to pay for administering those cleanup efforts. On the other hand, if President Blowhard's proposed elimination of the program is approved and we go back to the old way where states were not accountable for making progress, there would be an estimated 11% loss of food production. That is an annual loss of $1.3 billion in food production as opposed to last year's cost of $73 million for the EPA to run the cleanup program.

Even if we discount the value of improved aesthetics, climate, recreation, waste treatment, and air and water quality (should those criteria become less important in the coming decades than putting food on the table) we would be money ahead by continuing the federally administered program to clean up the Chesapeake Bay.  However, while we are in transition to a sustenance economy, these other affected sectors will initially reap 90% of the multifarious economic benefits. Among the beneficiaries would be real estate, tourism and hospitality, outdoor recreation, and public health; and with the increase in our food supply, there are starving nations today who could use our surplus.

There is a cost to all of this ecological restoration beyond the amounts in EPA and state budgets. It is embedded in industry compliance with stormwater and sewer regulations, mainly in connection with property development and agriculture (mostly carried by Department of Agriculture subsidies). There are also municipal wastewater treatment costs. All these costs may offset the various GDP increases from the restoration and that will continue to be the case until we learn that failing to account for externalities in choosing how we coexist with nature will always come back to bite us. The way to avoid this unhappy result in the future is to adopt a different economic motive that prioritizes permaculture principles. As Richard Heinberg explains,

'Village 1860' by Stuart Williams

"growth is ending anyway: we need to restructure the economy so it can provide what we really need (food, basic services) without the expectation of continual expansion."

The Chesapeake Bay in Greater Peril Than Ever

While the estuary on a stick known as Maryland girds for legal battles over continuing the federal program to restore the Chesapeake Bay, the global force of climate change will increasingly hamper the region-wide effort even if the program ends up being fully funded in the official federal budget.

We are already able to discern the impacts of climate change on the Chesapeake. For example, though most of the world is losing access to water, the northern Chesapeake Bay area where I live has gained 6.6 inches of annual precipitation over the last century. In some respects, this is beneficial, but the major negative effect of more heavy rain is runoff into the bay and its tributaries, causing pollution by nutrients and sediment. This is exacerbated by urbanization throughout much of the watershed. Building codes and local governments are racing to keep up with the problem of stormwater runoff caused by development.

Rising temperatures affects a number of other aspects of the bay ecosystem. One is the profusion of Vibrio bacteria which spreads cholera and a similar disease either by ingestion or through skin lesions.

Before President Blowhard dispenses with climate change throughout the executive branch, government-funded scientists are valiantly assembling reports explaining its observable and anticipated effects. With the amount of rainfall increase we have observed with just a 1.5 C temperature increase, it seems that we should expect significantly more in the coming decades if global temperatures continue to go up exponentially.

From Albert Bates at The Great Change

The graph here shows a generic temperature curve along with several global macronomic indicators modeled in the Limits to Growth study. You might note that the human population is expected to drop in about thirty years (as food becomes too scarce) and think that this will flatten the temperature curve, but there is a delay between cause and effect in global warming as vertically circulating ocean currents cycle over a millennium meaning that increases in ocean temperatures and release of dissolved CO₂ will not achieve their full effect on the atmosphere until decades after the greenhouse effect is arrested by lowering atmospheric carbon.

Bottom line: we can't restore the bay by taking our current inadequate measures. Rising atmospheric temperatures make it necessary to exercise even more severe measures to avoid pushing the bay beyond recoverable limits.  We should not only continue to limit runoff from new and existing development, but we also need to rethink urbanization in terms of permaculture and apply afforestation wherever we can.

Flood Warning

When I attended the Lake Lariat Preservation Committee meeting earlier this month, I was told that I should become a member of the committee in order to have legitimacy in the eyes of the HOA. However, I am not sure that lake preservation is what I want to advocate. What about doing away with the lake and letting Mill Creek be what it was 60 some odd years ago? Would removing the Lake Lariat dam eventually lead to cleaner water flowing into the Chesapeake Bay? This is a question any community with a dam should ask about their own watershed.

Photo by Anders Sandberg

Aside from the water quality question, dams can lead to rampant destruction and loss of life, as South Carolina learned in the wake of floods last year causing 36 dam failures! Not all dam failures cause loss of life, but 81 of 336 dams in Maryland (including Lake Lariat) are high risk hazards by virtue of the potential consequences of a failure. Thirty-six dam failures in one state weighed against 71 dam failures nationwide in the five years prior points to a possible tipping point. If it is, three factors can be blamed for placing many at higher risk of flooding catastrophes: more extreme rainfall, more development, i.e. impervious surface, and aging of dams.

Dams have been built over the last 100 years or so with liberal safety factors for maximum probable precipitation. Aging of those dams beyond their 50 year design life makes them vulnerable to rainfall extremes even under their designed capabilities. Add to that the furious climate-driven increase in rainfall in the Eastern U.S. and you get catastrophes like South Carolina's.

We are in the middle of one of those rain spells here in Maryland. After a 4" rain last week, we have totaled almost 5" in the last two days, with lots more to come in the next few days. Rivers are predicted to flood. Hurricane Matthew may drop more rain here next week. I doubt if our dams would be able to hold it all. If you live downstream of one, don't be like one of the 17 people killed by dam failure in South Carolina last year. Take any flash flood warning very seriously.

Maps for Every Occasion

It wasn't too many years ago that everywhere we went, one of the first things we bought was a street map. Years before I needed those, I was always sending off in the mail for topographic maps, as a good Boy Scout, to plan and carry out hikes wherever I happened to be living. With our lives these days being so digitized, it's a relief that cartographic resources are so freely available to us through personal computers. The kind of maps that I am able to pull up through my county's geographic information system (GIS) portal may be the truest reflection of local geospatial reality in all of cyberspace.

The type of map that has recently been most beneficial to me is a combined street, topographic, and property map. I printed a collage of these showing every house in the area around Lake Lariat at a scale convenient to paste on a foldable piece of cardboard, which I can carry wherever needed. The resultant map allows me to plan my bike rides in search of dog walkers and to track where I have found allies in my quest to improve our poop scooping score.

My foldable map also helped me to locate and size up a particular private property that is a prospect for limiting runoff into the lake through work that I hope to do as part of my Watershed Stewards Academy capstone project. After contacting the owner, I found out that the area where I hope to work is also part of an easement, which my street/topo/property map does not show. There may be other links or layers available that could have shown me this, but I suspect that there are still significant datasets that are not yet loaded into the county's GIS.

In planning this capstone project, another GIS, the Web Soil Survey, will be helpful in knowing how to treat the soil for all the plants we will be putting in, though soil tests will be performed to corroborate and refine that information.

Once the project is complete, we can apply yet another map-based tool, the Stormwater Management and Restoration Tracker (SMART), to claim credit for how much this project will help the watershed. Anybody can use SMART to claim credit for particular stormwater practices that have been installed on their property. In my case, that includes four rain barrels, a rain garden, and conservation landscaping. A good way for a watershed steward to get to know how in-tune people are to stormwater management is to do a local survey in order to populate SMART for those households. This would also be a way for organizations such as the Lake Lariat Preservation Committee to track and map work done in the lake watershed to improve water quality and reduce runoff and to reach out to constituents in order to raise issues related to lake preservation.

Saving the Bay, One Turd at a Time

I ran into local award-winning environmentalist, +Nancy Radcliffe and shared with her my new resolve for picking up any of my dog's droppings that might cause problems for the watershed. Nancy, who is a leader in the movement to ban plastic bags, suggested that I use newspaper instead of the dog poop pickup bags so freely available. I told her I would do that, so here is the method I came up with. Easier to grasp this idea through demonstration, so a 3 minute video was made. You can tell I'm a little nervous at first, but my voice slows down to a normal timbre at the end.

I jumped on Nancy's suggestion of newspaper as a collection device because it enables easier composting and doesn't waste plastic bags. It is possible to dump a dog turd from a poop bag into a compost bin, but the newspaper allows it to drop out easily and, if you are careful, the poop pickup bag can be used repeatedly.

In an effort to further reduce plastic bag use, I plan to transition to using paper bags to hold the newsprint protected poop. It's just a matter of being particular where I shop and making sure they offer paper bags. I might have to start buying wine by the bottle :).

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.

Filling the Berm

Biochar is well suited to Environmental Site Design (ESD) for stormwater management applications. Its ability to absorb up to six times its weight in water and its long drying time can be used in slowing down runoff to maintain discharge timing while increasing infiltration and evapotranspiration.

Many ESD standard practices include a gravel underlayment to promote drainage. Some of those same ESD practices do not contribute sufficiently to meeting the Channel Protection Volume (Cpv) requirement, i.e. the amount of water that is allowed to run off from a 24-hour one year storm (that is, the average of the largest 24-hour storms historically occurring in an area each year). Since Cpv is sometimes difficult to meet with ESD alone, traditional structural practices must sometimes augment the more distributed ESD practices.

One of the practices that does not contribute to Cpv is infiltration berms. These are long mounds

built orthogonally to the flow of runoff. They consist of 6" of topsoil over an aggregate core. If, like the Stockholm tree planters, we were to load the gaps in the aggregate with biochar, that much more channel protection volume could be earned based on the additional water holding capacity of the biochar.

Of the other practices that already contribute to the channel protection volume, a thick layer of unground biochar between the soil and the aggregate or gravel underneath would help prevent clay particles from blocking the drain, contributing thereby to a more sustainable solution.

Since these two modifications deviate from the specifications in the Maryland Stormwater Design Manual, special review and approval of the innovations would be required at the county and/or state level. MARVALUS Engineering may be the one to request approval of these innovative practices and then earn royalties on their application. Developers and owners probably wouldn't mind paying a small fee along with the price of using biochar if it saves them the expense and real estate of added structural devices or maintenance of the aggregate layer.

Filling the Niches

While our structural practices have barriers to innovation inherited from earlier versions of the Maryland Stormwater Design Manual that would impede adoption of Stockholm's approach to planting trees, the newer Environmental Site Design (ESD) practices appear to be more flexible. In Calvert County, additional flexibility is written into the stormwater ordinance that allows alternative treatment methods to be approved and used, as long as they meet the performance criteria of the Manual.

Photo by Donghee Bae (CC BY-NC-SA 2.0)

Among the ESD practices that lend themselves to inclusion of biochar in their construction are green roofs, reinforced turf, micro-bioretention, rain gardens, landscape infiltration and infiltration berms. The specifications for these practices not only offer biochar niches, but call for the added  performance that biochar so uniquely provides. 

• Green Roofs: the planting media spec calls for "a soil-like mixture," the base gravel layer could also be mixed with biochar, allowing longer roots and even more drought tolerance.
• Reinforced Turf: the spec requires that the turfgrass inside the permeable interlocking concrete pavers be grown on sand or sandy loam, which doesn't exclude the use of biochar to make the grass more resilient against drought and vehicle traffic.
• Micro-bioretention, rain gardens, landscape infiltration and infiltration berms: the spec allows for amendments to the loamy sand or sandy loam to bring pH to within 5.5 to 7.0. Acidic soils in the Coastal Plain could use biochar to raise the pH. The spec also discusses breaking up compaction from construction at the bottom of the bioretention basin. This refracturing step would be a good time to mix biochar into that 12" zone.

These aren't the only ESD practices that offer niche opportunities for biochar. One that might use great quantities of char in gravel niches is Submerged Gravel Wetlands. We just need to identify and quantify the costs and benefits of using that much char. 

At my first U.S. Biochar Initiative symposium, +Chuck Hegberg confided to me that the sector that offered biochar its best shot was not agriculture, but water. That sounded right at the time, but even more so now.

Breakthrough!

Fragipan is one thing, but what about soils that are highly compacted from the top down? This is a problem common in urban landscaping, and not uncommon in parts of suburbia as well. Compaction makes it hard to start and grow plants, including trees, which serve many important functions, especially in cities. The solution is excavation and replacement of the compacted soil with a suitable growing medium.

Photo of urban landscaping by thanh.ha.dang (CC BY-NC-SA 2.0)

In Stockholm, Sweden, one enlightened leader grasped the choice of replacement growing medium as an opportunity to introduce biochar into the mix whenever trees are being planted in civic landscaping projects. Biochar brings many advantages over commonly used peat moss, including its resistance to compaction. The biochar techniques used by Bjorn Embrén, head of landscaping for the city, were developed over decades and have shown stupendous results in the growth rate and survival of trees. The mixes they use include relatively little soil, but massive amounts of various grades of gravel and biochar. Tree roots find the open structure very accommodating.

Embrén's advice to cities who are interested in these techniques is "Dare to try it and you will be convinced!"  What we, in Maryland, must do first is make a few changes to the specifications for growing media in the Stormwater Design Manual, which dictates a loam/sand mix for infiltration devices. Adopting these techniques would make it possible to select from a wider range of vegetation in bioretention and filter devices, as biochar-based filters drain more quickly than those that rely primarily on soil.

At any rate, we shouldn't have to take the full development and test approach to begin adopting these designs - that part has already been done. All we need is a few delegations visiting Stockholm to see how to make them successfully. They can start by reading this manual. It is a bit old and doesn't use the term "biochar." The term they use instead, "structural soil," could have been key to adoption of the changes since it sounds so common sense and familiar.

Biochar to Improve Soil Drainage and Save the Bay

In Maryland, the Environmental Site Design (ESD) standard for water runoff is that it should mimic woods in good condition. This is difficult when impervious surfaces are being added, since the water collected and treated in stormwater management devices must then exceed what would be impeded and filtered if woodlands completely covered the unbuilt portions of the site, i.e. the additional effectiveness required increases with the amount of impervious surface introduced. The Design Manual qualifies the standard to require that it be achieved to the Maximum Extent Practicable (MEP). This is not as big of an escape clause as it may appear, since the manual also includes a checklist that helps determine whether the design process demonstrates a sincere MEP effort.

The idea of using wooded areas as the standard for all sites is very suitable for Maryland, as a glance at Google Earth will show how very wooded our state is. Yet, rumor has it that the next update to the manual will not be so stringent. As it is, the absolute minimum standard already obviates the wooded area criteria, if it turns out to be impractical on any given site. That minimum standard in the eastern part of Maryland is to design stormwater devices to hold an amount based on 1" of rainfall, ensuring that a specified portion of that water volume drains into the ground to recharge the aquifer. I hope they hold to the more rigorous ESD standard because the Chesapeake Bay will flourish if we can insulate it from the effects of our exploits on the land.

Photo by Birgit Speulman (CC BY-NC-SA 2.0)

Deep biochar-soil mixtures in planting beds would be an effective way to improve drainage, thus helping to meet the recharge volume requirement. Wet ponds are preferred to dry ponds, but you get less aquifer recharging since the water drains slowly in a wet pond. What you could do is use biochar to improve drainage of combination pond forebays, possibly allowing smaller overall pond size.

Here in Southern Maryland, we have a lot of Beltsville soils which are typified by a fragipan layer that is practically impenetrable. It may even reform after being broken up. Here again, biochar could help if it could be injected in fragipan layer breaches, preventing it from reforming. For the gardener, this might involve digging with a post hole digger and dropping biochar into smaller holes that have been chiseled through the fragipan. This would improve drainage considerably and, if the biochar was inoculated first and enough added, eventually eliminate the fragipan through microbial action.

Storming and Norming lead to Underperforming

Just from my brief exposure so far, I have concluded that the management of stormwater runoff is typical of our engineered environment in that much effort is put into the design and construction of a device, after which ensues a lifetime of neglect. It's not due to lack of regulation or even oversight, but a lack of attention by owners and a failure of governance. A well constructed stormwater pond can degrade due to erosion, poor control of vegetation, or flowpath blockages and remain that way for years, all the while earning its full TMDL credit, though performing only half as well as it should. The local authorities are loath to penalize or even notify violators of their maintenance obligations out of fear of having a negative economic impact on business. State and federal enforcers are just as remiss.

Now that Environmental Site Design has downscaled the control of stormwater to smaller devices spread throughout a new development site, it will be interesting to see whether things will be better maintained due to aesthetics and scale. Education will be key. Fortunately, the Design Manual spells out the maintenance requirements for each device type.

Here's the type of problems that degrade a stormwater pond. The photo here is from a place I frequent that has not been maintained much for about 5 years. Trees grow on embankments where the roots compromise the dam's ability to hold water. Banks are eroded into the pond, reducing the vegetation inside, causing pooling of water, and reducing the overall pond capacity. Cut trees are left inside the pond, putting more nitrogen into the watershed as they decay. I hope to catalogue many stormwater devices such as this in Calvert County over the coming months and use this in presentations to those who need to know. They will be posted on my newest tab on this blogger site.