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MMWD Blog: Think Blue Marin

Welcome to our blog! Written by staff at MMWD, “Think Blue Marin” explores all things water in south and central Marin—water supplies, conservation, new projects, watershed management, and more.

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Oct 28

Choosing Permeable

Posted on October 28, 2016 at 8:36 AM by Ann Vallee

by Charlene Burgi

Several months ago a stonemason completed the face of my fireplace with Three River rock. There was a fair amount of stone left over from that job, so I asked the stonemason if he could install a patio in the backyard using the remaining rock.

Shortly after my query, he submitted an estimate for the job that included concrete curbing, a 4-inch concrete base pad, and mortared joints. In putting the estimate together, he was no doubt considering the frost heave here in Lassen. He wanted to prevent the stones from moving as the earth undulates due to freezing and thawing. 

But my vision for the back garden was to maintain the excellent drainage from the permeable soils we have here. What this stonemason didn't consider is my home is built on rock cap—perhaps from Mt. Lassen's lava flows thousands of years ago. This rock cap, which is found several inches below the soil, curtails the frost heave. In sum, a permeable patio is a viable and beneficial option. 

You might ask what is permeable material, and why choose it for landscaping patios, walkways and even driveways? Permeable material is open to the soil. In other words, it is porous and allows water to flow through. This material can include rock, mulch, loamy soil, and even some types of asphalt that absorb surface water and carry it to the ground underneath, rather than forcing water to runoff or puddle on roads or sidewalks.

As to the why: Misdirected surface water and poor drainage can play havoc with landscaping. By allowing rainwater to work its way back into our soil via a porous medium, we can eliminate potential problems. For example, if a site is not properly graded and an impermeable material such as concrete is poured without thought to surface water, that water may end up under your house!

Drain pipes can carry water away from collection points, but permeable materials go beyond that to help evenly distribute rainwater throughout the landscaping. Just as bioswales on a hillside slow down sheeting rain, permeable surfaces provide an opportunity for water to spread out and sink into the ground. This recharges groundwater supplies instead of funneling runoff directly into to storm drains.

Finally, when water falls on impermeable surfaces—whether from rain or errant irrgation—it can collect pollutants and carry them to those same storm drains, local creeks, and the Bay. This polluted runoff harms our waterway ecosystems. In contrast, permeable surfaces help to filter contaminants. 

Misty on new patio
 Misty on the new patio
With all these benefits, permeable walkways, patios, and driveways are well worth investigating. Ask your landscape professional what options are best for your garden. As for the installation of remaining stone here ... much to the consternation of the stonemason, he installed the patio as directed by yours truly. Now I only need wait for spring to intersperse vibrant blue, low-water-using Turkish speedwell (Veronica liwanensis) into the areas where mortar was to be used. 
Oct 21


Posted on October 21, 2016 at 1:54 PM by Ann Vallee

by Charlene Burgi

Many years ago, Harve Presnell sang a song, "They Call the Wind Maria," from the movie and hit Broadway musical Paint Your Wagon. Lines in the song spoke of loss and of hearing the wind "wail and whinin'."

Wind can be so destructive. As an arborist, I know the damage that can be done by falling trees and broken limbs to everything in their wake. For many years I have recommended pruning evergreen trees to prevent them from forming sails and being ripped apart by the wind. During those years I had not considered the possibility of a deciduous tree falling into that niche. Last week's storm, however, told a different story.

Yellowwood remains
 Remains of yellowwood tree showing signs of heart rot
The gale winds we experienced in Lassen did their wailing and whining relentlessly during the night. In the morning, I assessed the property for damage. The greenhouse door was askew but fixable. The view to the chicken house, however, exposed itself in a way never seen before. The American yellowwood tree, Cladrastis kentukea, that stood proudly between the house and chicken coop had mysteriously disappeared. In its stead was a 3-foot piece of wood—what was left of the tree trunk. I found the rest of the tree 30 feet away. 

A conk, or mushroom growing on a tree, is an indicator of wood decay.
The tree had yet to turn its brilliant yellow before shedding its leaves for winter. Instead, the thick foliage created that deadly sail used by the wind to fell it. The remaining portion of the tree told another story, too. Though the tree was relatively young, the broken trunk revealed signs of a fungal disease known as heart rot. The disease had not yet progressed far enough to disclose telltale signs of conks (mushrooms growing on the wood). Unbeknownst to me, the tree trunk was weakened. Eventually the fungus would have taken the tree.

Winter is rapidly approaching, and with oncoming storms we need to be cognizant of trees in our gardens and outlying areas that can be affected by winter conditions. Marin has many native and non-native trees that are naturally weak-wooded. Eucalyptus, pine, cypress, fir and bay trees can have difficulties withstanding the high winds experienced in Marin. Before branches are compromised, or roots fail to hold up these magnificent trees, consult with a good arborist to ensure Maria doesn't play havoc as she did with the yellowwood tree in my garden. The time and expense now will be well worth it in the near future.

Oct 14

Irrigation Components

Posted on October 14, 2016 at 10:44 AM by Emma Detwiler

By Charlene Burgi

A friend came over to the ranch in Lassen this morning to help me winterize the outdoor plumbing and install various heaters to prevent water from freezing in the troughs for the horses and donkeys.

The process seemed simple enough, until a 3/4 inch plug was requested and the hunt was on. If you have ever walked through an irrigation supply business, or just sauntered down the irrigation aisle at a hardware store you understand what I faced.

Within the business existed buckets of various irrigation components in sizes ranging from 3/4 inch to 4 inch diameters. PVC tees were mixed with street ells, couplers, 90's, caps and slip fixes - to name a few. Other buckets contained drip components too numerous to mention. It would take a long time to find what we needed and I recognized it would be faster to drive somewhere to buy a new plug than spend hours trying to locate one in the dozens of buckets filled with PVC parts. Mentally I put those buckets on my bucket list to organize - a worthy winter project.
Sample of irrigation parts
You might ask why the need for all those parts and pieces? Irrigation systems require having spare parts in case there is a break. Typically people only need a slip fix or compression coupler for a broken pipe equal to the size of pipe they have in the ground. On occasion, a riser will break that holds up a sprinkler. Even a few nozzles held in supply are good insurance in the event of breakage. Drip systems frequently throw off a drip emitter, pop an end cap or find a split in the tubing. Spare parts are needed.

The key to being prepared for these water wasting leaks is knowing what you have and matching the component to your irrigation system. For example, if your sprinklers are spraying out 15 feet, you would want to have the same brand nozzle that also sprays 15 feet at the ready if replacement is needed.

Matching brands is important since each company produces nozzles that may emit the same amount of water but they are constructed to produce a different amount of gallons per minute if it is an overhead spray system. By mixing and matching brands, your irrigation system will cause an uneven spray pattern. Equal water sprayed for each valve is known as distribution uniformity. You will find your garden thriving, running efficiently and effectively as if it was raining outside by matching nozzles to what exists on the system, matching the spray pattern and the distance the water sprays.

Sizes and manufactures matter
Have you checked your irrigation system lately? Do you have any leaks or breaks? Do you have the necessary irrigation components to make repairs or are you also facing vast quantities of mixed and matched parts? Worse still - perhaps there are no parts that exist to fix the problem.

Have a great weekend, and don't forget, the California Native Plant sale is this Saturday!