“Earthworks are much like the skeletal frame of our bodies they support the system allowing us to fill the body or land with a living muscle and skin”.

Earthworks are like hardware and software. When designing it’s always essential to keep in mind what will run water off (called hardware) e.g. roads, roofs (will give almost a 100% run off) and what will absorb water (software) i.e forest, healthy soils, and gardens. We are always looking at hardware as water harvesters to divert to our software, water storages.

For a copy of our brochure click here EarthWorksCourse6_7AugustPermaWorksBrochure

About the location

Northern NSW, Farrants Hill is on the north east extent of the Tweed Caldera, the remnant of the Mt Warning Shield Volcano that erupted 23 million years ago. The property is 2 acres of undulating semi-cleared land overlooking the Tweed Valley. It exhibits many elements of this volcanic origin and will be further explored in the course.

The property is halfway between Murwillumbah in the centre of the Tweed Valley and the beaches of Cabarita and Kingscliff. It is just 5 minutes off the Pacific Highway and there is ample accommodation in the area. For a list of accommodation in the area please click on this link.

Objective

Students will understand the basic principles of permaculture design in earthworks: reading the site, interpreting contour maps and using surveying tools, and placing elements in a design. Students will be able to use the basic terminology for earthworks and soil water management.

Contents

Thinking Earthworks

When thinking earthworks design the aim is to keep water as high in distance and long a time in the landscape as possible. Water and the water’s edge is 30 times more productive than other land, this is the classical edge effect. Earthworks are the major element in design when we start with any design.

Terms Used in Earthworks

Surveying-Learning how to survey is a simple process once you have been shown using water levels/bunyip levels to the high tech laser levels.

Keyways - When constructing a dam/pond, or excavate below original ground level for the keyway much like a woodruff key on a drive shaft it locks the wall in place also excavating below ground level you stop water from leaking under the wall. The keyway is constructed with the best quality material you have from the site.

Keypoints -Keypoints are where the land form goes from convex to concave, the point of transition, the highest economical place in the landscape for dam placement, not all landforms have them, its only in the humid climates they are formed.

Planning of Earthworks

Swales - A water harvesting ditch on contour, swales are a tree growing mound and have multiply benefits.
Aid the reforestation of landscape through the rehydration of soil across a section of land and providing seed for dispersal by wind or gravity.
Flood proof and drought proof land.
Swales can be a link to dams/pond to help charge the dam once full, plus act as an emergencies back flood system for the security of the dam if the swale is linked to the dam spillway.
Swales don’t work if there are no trees they become a contour drain.
It is essential that swales are planted out with a mix of tree species which aid in the water peculating into the subsoils through the roots of trees.
Swales help clean water before leaving the site allowing sediments, manures, detritus to drop out by gravity to swale floor, fertilizing trees and anything else below.

Dams - Barrage/valley dam, consist of constructing a compacted earth wall across the valley.
Keypoint dam is the same as a barrage dam but much higher in the landscape constructed so the high water mark is at the keypoint of the valley, it is the most economical dam to build; also using the natural ley of the land to harvest water.
Contour dam is as the name suggests it is constructed on contour of usually gentle country with interlinking swales or diversion drains to fill the dam.
Ridge point dams are constructed at the end of a ridge usually it’s the highest dam on a farm.
Saddle dam is similar to a ridge point but much cheaper to construct as there is less earthmoving required it consists of constructing 2 walls either side of the saddle on the ridge.
Turkey’s nest or ring dam is mainly constructed on flat country as an open earth tank for either flood irrigation or water storage for stock.

It’s best to plan all aspects of the earth-moving process before the machines or labourers arrive.

1. Peg out site using a level (laser level, dumpy level, a-frame, bunyip level)
Making the final decision of placement of dams, roads, swales ect.
2. Test soil by auger holes, soil samples and soil pits to check if suitable for your needs (ie. Dam needs at least 30- 40% clay). Seek professional advice or do more research before deciding conclusively.eg test holes
3. Quantify volumes of earth to be moved, to hours of machine hire to give you real figure of cost involved.
4. Plan a space to store all the TOPSOIL. Never allow it to be mixed. Remove carefully to be returned later as growing medium.
5. Have on hand as many seeds and plant material as is needed to immediately cover disturbed soil.

Dam sealing - Sealing of problematic dams that are leaking, with gleying, manurial pugs or bentonite.
Dam wall and spillway repair and retrofits
Often exiting dam walls don’t have enough freeboard and the spillways are badly placed, it’s really a simple matter of raising the wall height and fitting back flood swale and a level sill spillway.
Minor land forming for benches, house/shed sites, terraces etc.
Weather your retrofitting or building new infrastructure installing gardens there is allways minor earthworks to be done.
Level-sill-spillways-

Diversion drains - A maximum fall of 1m in 400m or less, for every meter it falls 2.5mm which is hardly perceptible but enough to make water move to a point usually storage point e.g. Dam/pond but not fast enough to erode or carry sediments.
Earth moving machines types and uses.
There all sorts of earth moving machines finding out what’s best for your job can save you $1000’s.

Roads as water harvesters - Roads can cause erosion and concentrate overland flow of rain events to culverts/pipes where the water is speed up when forced through the pipe coursing more erosion.
But they can be a great source of hardware to harvest water from. In farm roads where possible we can design roads with a 1m in 400m fall to harvest water to charge dams, we can get multiply functions from a road ease of access water harvesters, fire breaks ect.
roads-as-water-harvesters

About the Trainer

David Spicer grew up in the snowy Mountains, this hard cold and bloody hot environment made him what he is today. His father was a heavy machinery operator on many large construction sites, David grew up around this machinery. David followed in his Father footstep with his love and great skills to use machinery.

David Spicer’s approach to design and education is based upon a proven emphasis on practicality, having over 16 years experience in Permaculture education working and teaching with Bill Mollison at the Permaculture Institute (Tasmania) and Geoff Lawton, the managing director of the Permaculture Research Institute of Australia and Zaytuna Farm. He is renowned for his ability to explain concepts and ideas simply, and getting to the basics. David previously worked as farm manager of the renowned Tagari Farm and Zaytuna Farm in northern New South Wales.

He has taught and worked extensively within Australia and internationally on various projects, covering six Australian states, Morocco, Jordan and Palestine covering a broad array of different climate zones. David is a valued member of the permacultureconsultants.com team headed up by Geoff Lawton. He has the distinction of being Registered Teacher #5 with the Permaculture Research Institute of Australia.

David currently serves as Lead Consultant and Educator for http://www.permacultureworks.org/

About the Course

Venue: 116 Farrants Road, Farrants Hill

Meals: Morning Tea, Lunch and Afternoon tea will be provided.

What to bring: Work boots, hat, water bottle, wet weather gear, ear and eyer protection, note book and pen, and sunscreen.

When: 6 th and 7 th of August 2016 from 9 am till 5 pm

Fee: Early Bird rate $360 on available till June 2016 only maximum of 20 places available!

Standard rate: $400

Accommodation: Some camping is available at the site, there are limited places available so please make sure that you let us know if you would like to camp (just add this note to the emailed form (see below).

Booking information: All booking will have payment made at time of booking. Please click on the link below this will take you to our website for booking and payment.

Enrolment Form: Enrolment form for course with Permaculture Works