Check out the Geyserville Stream Bank Stabilization Project After One Year on the CalTrans Live Web Cam.  Lets keep watching it as the high waters begin (if it ever rains again in NOCAL)
 
You can take a look at photos during construction and photos of the site during high water here: 
RockVanes:
Rock Vanes were an integral component in redirecting erosive flows away from the stream bank and managing the thalweg at the project site.
By the Way, if you want to learn more and watch more video, you should check out Dirt Time over at Forrester University.  Over there, you can watch a video, take a test and earn PDH.  It’s the perfect way to learn Environmentally Sensitive bank stabilization techniques or want to provide online training for their staff or earn Professional Development Hours.
UP and coming!!
John McCullah- owner Sailx Applied Earthcare and Donald Gray- from the Dept. Civil and Envl., Engr., University of Michigan, are presenting the paper “Bank Stabilization at Geyserville Bridge Site Using Re-Directive and Bioengineering Measures” at the ASCE GeoCongress in Oakland March 26-29 2012 https://content.asce.org/conferences/geo-congress2012/index.html

 

Hey Everybody!

Let’s talk some COMPOST, shall we!

Compost is such an effective, versatile tool in the world of erosion and sediment control.  Sadly though, it seems that it is often misunderstood, misued or too quickly dismissed.  A lot of that might be due to a lack of good information out there.  So, here at WatchYourDirt and Dirt Time, we thought we’d do our part and try to add some quality information to the mix.

So, we took some really good Compost-centric excerpts from our video and Erosion Draw Software libraries to give you a sampling of what those educational tools have to offer.  The video comes from the ‘Big Cover Up’ episode of our Dirt Time video series, while all the other information is taken from the Erosion Draw software tool.

ErosionDraw is a great tool that covers tons of erosion and sediment control techniques, giving not only the full information (description, advantages, disadvantages, comparisions, installation, etc.) but, ErosionDraw also gives access to the full CAD drawings as well.

If the information below looks good to you.  You may want to give our videos and software a quick look 🙂

 

COMPOST BLANKETS

Definition

A compost blanket is a layer of compost designed to prevent erosion, especially rills and gullies that may form under more traditional methods of erosion control. In many cases, a compost blanket can be more effective at vegetation establishment, weed suppression and erosion control than an Erosion Control Blanket (ECB) or Hydroseeding. Compost blankets can be applied by hand, conveyor system or compost spreader; however, the most cost-effective and efficient method is the use of a pneumatic delivery system, i.e. a compost blower truck.

Purpose

A compost blanket is used on slopes to prevent raindrop erosion and in some cases, to increase infiltration rates. A trademarked form of a compost blanket, the Rexius EcoBlanket™ increased infiltration rates and decreased sediment delivery by 99% as compared to bare soil, in a study conducted by the San Diego State Erosion Control Laboratory (Rexius). The success of compost blankets is dependent upon the blanket not being undermined by water; this can be accomplished by keying in the top of the blanket, or the use of a compost berm or sock at the top of the slope. When applied correctly, compost blankets provide nearly 100% surface coverage. (Faucette, 2002)

Advantages

  • Compost blankets can be more effective than ECBs, because they come in better contact with the underlying soil, reducing the chance of rill formation. (Faucette, 2002).
  • Compost is organic, biodegradable, renewable, and can be left onsite. This is particularly important near streams.
  • Compost has been shown to suppress weeds. Over two growing seasons, the mass of weeds on compost blanket plots was 1/3 of the amount on the control plots (Glanville, 2003)

 

Conditions Where Practice Applies

Compost blankets are usually used on slopes of 2H:1V or gentler, but can be used on slopes as steep as 1H:1V, with consideration given to the length of slope and depth of application (AASHTO). Adding components such as a tackifier, or using compost blankets in conjunction with other techniques can increase the allowable steepness of the slope to be treated. Compost blankets should be extended 3-6 feet over the top shoulder of the slope to prevent water from getting underneath. Compost blankets should not be applied in areas of concentrated flow, and can be used in conjunction with compost berms or socks.
Blankets can be applied in a variety of thicknesses from ½” to 4”, depending upon the intended purpose. As a general rule, the more precipitation an area receives, the thicker the application.

 

Compost Specifications

There are many types of compost, all with different properties, so it is best to determine what application the compost is being used for. Compost can be derived from feedstocks, biosolids, leaf and yard trimmings, manure, wood, or mixed solid waste, and must be treated with heat to remove pathogens and destroy noxious weeds.

One of the most important criteria for quality compost is the temperature it was “cooked” at and the duration of composting. For instance, California Compost Regulations require that “windrowed compost” be kept at 131°F for 15 days and turned 5 times. Compost manufactured in bags is referred to as “in vessel” which the regulations require be kept at 131°F for only 5 days. Quality compost will then be cured for 60 days (D.Carvalo, personal communication, 2004).

Click Here for California Department of Transportation Specifications for Compost Blankets

 

Installation

Compost blankets can be applied in a variety of ways, however the most efficient and cost-effective way is through the use of a pneumatic blower truck.

  • Prepare the slopes by removing loose rocks, roots, clods, stumps and debris over 2” in diameter.
  • Trackwalk slopes if feasible before application.
  • For very steep slopes, compost berms can be installed at intervals over the compost blanket in much a similar manner as Straw Rolls.

 

GET MUCH MORE INFORMATION:

For MUCH MUCH more information on Compost Blankets and Berms including CAD design drawings, pick up a of Erosion Draw software!! 

For more video, you can purchase our ‘Big Cover Up’ DVD or go all out and get the Dirt Time Ultimate Set – which contains our Big Cover Up episode, as well as Compost applications in 3 other episodes.

Tons of information is right at your finger tips – all available through the WatchYouDirt and the WatchYourDirtStore.

Any questions or comments, give us a ring in the comments below!

Bioengineering in the Silicon Valley – Circa 2003
I just came across this project paper in our Salix archives – thought it was worth sharing.  At the turn of the century, San Jose CA was one of the fastest-growing regions – read “uber-urbanization”.
The Santa Clara Valley Water District has had some HUGE challenges over several decades – challenges to reduce flooding, recharge the aquifers, and simultaneously restore aquatic and salmonid habitat.  How does an agency restore stream function in deeply incised streams with no room to move horizontally because urbanization has encroached into the floodplains? 
The Guadalupe River is one such stream, running right through the middle of San Jose.  To prevent flooding the SCVWD once had a duty to reduce flooding armoring many miles of stream with sack concrete walls. 
Improperly installed coir netting – the rolls wer installed downslope direction instead of with flow
This paper describes the challenges in achieving “Green Solutions”, agencies going “overboard” a bit by not allowing any rock once the concrete sacs had been removed and, most importantly, how it is imperative that TRMs are installed properly.

DOWNLOAD THE PAPER HERE

Installed properly as a TRM should be, check slots, rolled with flow direction etcAfter one year and several high flows – success

Hey Everybody,

We’re thinking of doing a series of posts about different Erosion & Sediment Control and various Streambank techniques.  Kind of a basic knowledge, information-rich, get-to-know-your-tools type of thing.  So, let’s give it a go shall we?

Let’s talk Live Silitation! 

TWO QUICK NOTES

DESCRIPTION

 Live siltation (also known as Vertical Brush Layering) is a revegetation technique used to secure the toe of a streambank, trap sediments, and create fish rearing habitat. The system can be constructed as a living or a non-living brushy system at the water’s edge.

PURPOSE

Live siltation helps to secure the toe of a streambank, and trap sediments.

CONDITIONS WHERE PRACTICE APPLIES:

Live siltation is an appropriate practice along an outer bend with sufficient scour or toe protection.

PLANNING

Useful for Erosion Processes:

  • Toe erosion with upper bank failure
  • Scour of middle and upper banks by currents
  • Local scour
  • Erosion of local lenses or layers of noncohesive sediment
  • Erosion by overbank runoff
  • General bed degradation
  • Headcutting
  • Piping
  • Erosion by navigation waves
  • Erosion by wind waves
  • General bank instability or susceptibility to mass slope failure
  • Erosion by ice and debris gouging 

Spatial Application:

  • Instream
  • Toe
  • Midbank
  • Top of Bank

 Hydrologic / Geomorphic Setting

  • Resistive
  • Redirective
  • Continuous
  • Discontinuous
  • Outer Bend
  • Inner Bend
  • Incision
  • Lateral Migration
  • Aggradation

Design Guidelines / Typical Drawings:

Cuttings should be placed adjacent to the water’s edge to ensure effective sediment trapping and velocity reduction at the toe of slope. At least 40 branches per m (12 branches per ft) should be installed.

ENVIRONMENTAL CONSIDERATIONS / BENEFITS

This is a very effective and simple conservation method using local plant materials. This technique is particularly valuable for providing immediate cover and fish habitat while other revegetation plantings become established. The protruding branches provide roughness, slow velocities, and encourage deposition of sediment. The depositional areas are then available for natural recruitment of native riparian vegetation.

HYDRAULIC LOADING

This technique may be used for velocities up to 2 m/sec (6.6 ft/sec), but velocities should be at least 0.25 m/sec (0.8 ft/sec) for the system to function properly.

COMBINATION OPPORTUNITIES

Live siltation techniques can be constructed in combination with rock toes, Rootwad Revetments, Coconut Fiber Rolls, Live Fascines, and Brush Mattresses.

ADVANTAGES

This is a very effective and simple conservation method using local plant materials. This technique is particularly valuable for providing immediate cover and fish habitat while other revegetation plantings become established. The protruding branches provide roughness, slow velocities, and encourage deposition of sediment. The depositional areas are then available for natural recruitment of native riparian vegetation.

LIMITATIONS

If using a living system, cuttings must be taken during the dormancy period.

MATERIALS AND EQUIPMENT

Natural stone, willow wattles, logs or root wad revetments are needed for toe and scour protection. The live siltation will require live branches of shrub willows 1-1.5 m (3.5–5 ft) in length. The branches should be dormant, and need to have the side branches still attached. Any woody plant material, such as alder, can be installed for a non-living system.

CONSTRUCTION / INSTALLATION

Construct a V-shaped trench at the annual high water (AHW) level, with hand tools or a backhoe. Excavate a trench so that it parallels the toe of the streambank and is approximately 0.6 m (2 ft) deep. Lay a thick layer of willow branches in the trench so that 1/3 of the length of the branches is above the trench and the branches angle out toward the stream. Place a minimum of 40 willow branches per m (12 branches per ft) in the trench.

Backfill over the branches with a gravel/soil mix and secure the top surface with large washed gravel, bundles/coir logs, or carefully placed rocks. Both the upstream and downstream ends of the live siltation construction need to transition smoothly into a stable streambank to reduce the potential for the system to wash out. More that one row of live siltation can be installed. A living and growing siltation system typically is installed at AHW. A non-living system can be constructed below AHW during low water levels. If it is impossible to dig a trench, the branches can be secured in place with logs, armor rock, bundles made from wattles, or coir logs.

COST

0.7-2 work hours per linear m (0.2-0.6 work hours per linear ft), plus willow stock if not readily available on site.

MAINTENANCE / MONITORING

During the first year, the installation should be checked for failures after all 1-year return interval and higher flows, and repaired as necessary. During summer months of the first year, ensure that cuttings are not becoming dehydrated.

COMMON REASONS / CIRCUMSTANCES FOR FAILURE

Cuttings will not promote siltation as well if not located at the water’s edge. If located further up the bank, cuttings may dry out, and will only trap sediments and slow velocities during high flows. Cuttings may not grow well if not handled properly prior to installation. See The Special Topic: Harvesting and Handling of Woody Cuttings for proper handling instructions.

For more information, pictures, diagrams and examples, sure to check out our erosion software program E-SenSS (click here)

Hey All

Remember the Schenk Creek project?  It was the little seasonal creek below Highway 330 in San Bernardino National Forest that got inundated with DG sediment when a landslide occurred in the winter of 2010.  Remember District 8 had to design and build some really huge wire mesh-reinforced walls and also remove over 16,000 CY of material from the creek.

I got called in to restore the stream.  See this post for more information.

Well, Jason Bill recently sent me some photos taken on August 3rd – Three months later.  See how well the willow worked when incorporated into the restoration work.

The most interesting and informative techniques/prescriptions used for the stream bank stabilization included Longitudinal Stone Toe (LST) , Live Siltation , and the RSP Soil Flapping.  The LST and Live Siltation techniques are available in the ESenSS Manual (or NCHRP Report 544) and the RECP Soil Flapping Technique comes from a recent course we are teaching for Caltrans Landscape Architecture (See https://www.dot.ca.gov/hq/LandArch/ec/steep_slopes/recp_wrap.htm)

The Soil Flap method is really beneficial for steeper slopes (>2H:1V) that require a some reinforcement.  The horizontal element embedded in the slope provides geotechnical reinforcement while the “flapping” element provides erosion control.  Soil Flaps are not as strong as Soil Wrap but they are super cost-effective and constructible!

https://www.dot.ca.gov/hq/LandArch/ec/steep_slopes/recp_flap_with_brush_layering.htm

Just a reminder that these techniques and more are available on ESenSS or in the NCHRP Report 544, 2005.  See index to techniques PDF 

Hope you all recall that soaking willow branches for a few days to a month will increase the successful establishment. 

Some more photos here to see how the structures were built in Schenk Creek back in May.

Hope to see you all out in the field and keep your willow branches wet!!

-John

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