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    A Facebook Update!

    Earlier this week - we blogged about John McCullah - our beloved host of Dirt Time, being busy in no where else than Malaysia (AGAIN THIS YEAR!)

    Yes! Pictures are up here on how the project is going - but another update has been spotted on our Facebook Page! WAIT! WHAT? YES! We are on the FB!

    Like us on FaceBook @ 



    John is in Malaysia... AGAIN!

    Hello! This just in from the other side of the GLOBE!!!

    John is in Malaysia with Wing where they are working on and Engineered Newbury Riffle and the first Bendway Weirs in that part of the world.

    John says the first few day were filled with construction logistics - getting equipment lined up and visiting local quarries to get the right rock.

    The project is about 30 km below a large dam near the border with Thailand.  The purpose for the work is to raise the water elevation so a large series of pumps can utilize the river water for irrigation of farms and rubber tree plantations.  

    First thing was to dismantle an old gabion check dam that had been built to serve that purpose - unfortunately the river had “blown out” around the check dam.

    Check out the HOT OFF THE PRESS PICS!!

    More on the design and construction later.  



    StormCon Conference August 2014 Attendees

    Hello Hello!

    As John McCullah and David Derrick promised - their presentation are up and ready for your viewing here at ! Please see to our Navigation Bar and click on the "WYD FIles" Link! There you will see our StormCon Presentations Folder! Or simply CLICK HERE !!!

    Evaluations of the course will be out soon!

    Thank you all for attending!

    - The Dirt Time Team


    Project: OPAL CLIFFS (Chapter from Bioengineering Case Studies)


    PROJECT TYPE: Bluff Repair
    and Stabilization




    CLIENT/OWNER: Local Homeowner


    TRM, Live Staking, Hydroseeding


    Drive, Santa Cruz, CA 


    GEOMORPHIC SETTING:   Sea cliff subject to active erosion and periodic retreat.  The Opal Cliffs-Capitola reach is characterized by an irregular shoreline backed by cliffs ranging from 35 to 75 feet in height.  The coastal cliffs throughout most of the city of Santa Cruz and neighboring Capitola are composed of erodible sediments of the Purisma Formation (siltstone and sandstone) along with the Santa Cruz Mudstone.  These sedimentary rocks are often capped by 6 to 20 feet of unconsolidated marine and non-marine terrace deposits.  The horizon-tal bedrock stratigraphy is easily visible in exposed or bare sections of the cliffs.

    SITE CONDITIONS AND PROBLEMS: The Opal Cliffs section of the coastline is at high risk from erosion, the narrow beaches provide little protection from wave attack at the base of the cliff.  Urbanization and house building at the cliff top causes further sub-aerial erosion threats, viz., concentrated runoff and subsurface seepage from streets, drains, downspouts, and excessive lawn watering.  The face of the cliff at the location of the residence was actively eroding and retreating (see Fig. 20.1).

    Figure 20.1 – Coastal bluff before treatment


    TREATMENT OBJECTIVES AND CONSIDERATIONS: As a result of the high erosion risk from wave attack large sections of the sea cliff are protected by struc-tures including sea walls and rock revetments.  The base of the cliff at this location is protected by a sea wall and rock armor.  The main problem appeared to be erosion and shallow sloughing at the face of the bluff.  The goal was to arrest this erosion and stabilize the face.  Adjacent stable sections of the cliff were well vegetated.  If the face of the bluff was stabilized sufficiently this would allow the establishment of vegetation which in turn would help control erosion problems.  There was insufficient evidence of emergent seepage at the bluff face to warrant installation of horizontal drains (hydraugers) on the bluff face or a trench interceptor drain atop the bluff. 



    •  Anchored TRM: A three-dimensional, turf reinforcement mat (TRM) was draped over the cliff face and anchored (nailed) to the slope by driving pins with large washers through the TRM into the slope (see Fig. 20.2).  Workers rappelled down the bluff face on ropes to drive the pins.  Two-foot long anchor pins were inserted on 3-foot centers (see Fig. 20.3).


    • Live Stakes: Once the TRM was securely fastened to the slope, live willow stakes were inserted through the mat into the slope (see Fig. 20.4).  The near vertical inclination of the cliff face required that this installation be done by workers suspended by a rope and sling system from the top of the bluff.
    • Hydroseeding: A specially designed mixture was sprayed on to and through the turf reinforcement mat by workers suspended on ropes from the top using hand held spray nozzles (see Fig. 20.5).  The mixture consisted of Flexterra @ 4000#/ac, native grass seeds (Maritime mix), Jumpstart (Profile) humic acid, and BioPrime (Profile) mychorrizae.

    OBSTACLES TO IMPLEMENTATION: The main obstacle to implementation was the need to work on a near-vertical slope which required the use of ropes and slings.  A system was quickly developed, however, that overcame this challenge without the need for an elaborate scaffolding or support system.

    PERFORMANCE EVALUATION: A vegetative cover was soon established that was initially held in place by the anchored TRM.  This provided enough time for the live stakes to root and gain a toe-hold on the steep slope.  Erosion and shallow sloughing on the face has been arrested (see Fig 20.6).  Only time will tell whether this treatment will suffice in the long run, or whether other measures such horizontal drains and/or an interceptor trench drain will be required.

    Figure 20.6 - Views of bluff site immediately after treatment




    1. Bio-stabilization measures can be used effectively to repair and stabilize the face of coastal bluffs. Special anchoring provisions may be required when attaching a TRM to a near vertical slope face.
    2. The combination of an anchored TRM and live staking were used in conjunction with a site adapted hydroseeding mix to stabilize a bluff face.




    Brabb, E. (1997).  Geologic Map of Santa Cruz County.  US Geological Survey, Menlo Park, CA


     This is another great chapter out of Bioengineering Case Studies . Please see to the previous link for information on ordering your copy today!

    Thanks for Reading!!!

    - The Dirt Time Team



    John and David Teaching Course in Portland 


    Hey Stream People and Potomologists

    David Derrick and John McCullah are teaching a course  in Portland on August 4th at StormCon.  This will be a great chance to catch John and Dave "together again”, teaching a new course entitled “Repairing Entrenched, Incised, and Degraded Urban Streams - Techniques and Case Studies”.  

    Go to for more information.


    Portland is August!, what could be better?  And attending the StormCon Conference should be a wonderful educational and networking opportunity.  How better to catchup on the new NPDES and General Permit requirements AND solutions. 
    Dave and I are hoping to get a Stream Restoration Track as a regular part of the StormCon Conference.  Please help us by attending if you can.

    Repairing Entrenched, Incised and Degraded Urban Streams – Techniques and Case Studies


    Urbanization, with its associated decrease in overall infiltration and increases in impermeable surfaces, along with a proliferation of hydrologic and hydraulic sciences that “get the water off the site”, frequently result in incision of the associated urban streams.  Not just urbanization but also other anthropogenic factors such as dams, heavy long-term grazing, highly roaded timber areas, and instream gravel mining.

    Urban stream entrenchment, incision, and degradation are a high-priority, national issue leading to poor water quality, loss of riparian function, loss of aquatic habitat and costly threats to infrastructure. The new provisions of the Clean Water Act are an attempt to deal with these issues.  Post-construction BMPs and revegetation requirements, along with LID and other reductions of hydromodification during development and construction are now required as part of the NPDES program.

    Urban streams which are “properly functioning”, are often mimicking pre-development conditions - with healthy stream buffers, riparian zones, and instream function that can often ameliorate the effects of urbanization and other anthropogenic land use problems.

    This course will deal with some of the tools needed to design and build naturally-functioning stream, river, and creek reaches.  The material will be presented with the extensive use of Case Studies.  John McCullah will present projects utilizing Bioengineering and Environmentally-Sensitive techniques from US, and Canada, to New Zealand, some spanning over 15 years. John will also use some Dirt Time Video Clips to present projects. You can almost smell the diesel and dust!

    David Derrick will present many projects from his extensive collection of stream projects.  David promises a new Case Study from a Urban Steam project in the Cleveland area.  He says, “this project has it all - all the urban area concerns from stormwater to Riparian Buffers to Parks …"

    In 2005, the Transportation Research Board and National Cooperative Highway Research Board published NCHRP Report 544 – Environmentally Sensitive Channel and Bank Protection Methods Report 544- Environmentally Sensitive Channel and Bank Protection Methods.  This report, authored by J. McCullah, D. Gray, and D.F. Shields was published on CD and includes over 50 Techniques, from re-directive Rock Vanes and Bendway Weirs to Vegetated Rip Rap and Longitudinal Stone Toe with Live Siltation. It incorporates design considerations, construction specifications and detailed drawings.  An Educational Version of this design guidance document will be provided free to all StormCon class attendees. $100 value