‘p a yeomans-keyline in new caledonia (20 min) 1965’ (film descriptive paper & calculations)

P.A. Yeomans (Producer) (1965). Keyline in New Caledonia: Operation ‘Flood-Flow’. Sydney, NSW: Keyline Production. Film Descriptive Paper and Calculations written from watching the Film and reading the Script only.

Written for Keyline Archive. www.youtube.com/channel/UCUPgPJZAlkxt207sxcdp4DQ/about P A Yeomans-Keyline in New Caledonia (20 min) 1965 www.youtube.com/watch?v=gkrZVIeaYxk © Geoffrey Booth Nov 2011. Acknowledgement Required. For Educational Purposes Only. Not for Commercial Use.

v 2.0 1

Film Descriptive Paper and Calculations for ‘P A Yeomans-Keyline in New Caledonia (20 min) 1965’

This is one of the first films depicting a Keyline Flood Flow System consultancy by P A

Yeomans, on the tropical flatter land of the swampy upper Salée River valley, near the coastal port of Népoui, 146 miles (235.0 km) northwest of the capital Noumea, New Caledonia.

The wet season is at the end of the year and the dry season in the middle. Annual rainfall is

33 inches (~0.8 m).

Photo 1: On the left, the water from the river flows in the diversion channel to the newly constructed Keyline lake.1

Water from a braided stream of the river is directed through a water-gate (see Photo 2) into

a gently falling diversion channel (and, away from the swamp, changes shape to intercept rainfall run-off in the encountered undulating country) all the way into a shallow creek valley.

In order for this river water to irrigate the greatest area of land, a flat channel takes the

shortest path (making the water available higher in the landscape) and short circuits the shallow creek valley by going straight across the valley on a viaduct wall, incorporating in it an access road.

(The diversion channel section beyond the swamp will become the source of water for a

future Keyline Pattern Irrigation System on the downhill side, and is not the subject of this film) This 35 foot (~10.7 m) wide viaduct wall forms a lake behind it of 90 acres (~36.4 ha) area.

1 Yeomans, P.A. (1965). Film Script: Keyline in New Caledonia: Operation ‘Flood-Flow’. Sydney, NSW: Waite & Bull Pty

Ltd. (out of print) Yeomans, P.A. (1965, 1968). Water For Every Farm. Sydney, NSW: The K.G. Murray Publishing Company Pty Ltd. opposite p144, i.e. Plate 23 (out of print) Yeomans, P.A. (1978). Water For Every Farm Using The Keyline Plan. Sydney, NSW: Murray Book Distributors Pty Ltd. p145, i.e. Plate 23 (out of print) Yeomans, P.A. (1981). Water For Every Farm Using The Keyline Plan. Katoomba, NSW: Second Back Row Press Pty Ltd. p145, i.e. Plate 23 (out of print)



v 2.0 2

Photo 2: The open river water-gate, right, and the flow from the river in the diversion channel.2

Photo 3: This earth wall across the creek has a 35 ft wide elevated channel (left) and a roadway (right) on its crest.3


Ltd. (out of print) 3 Idem



v 2.0 3

River water is diverted by a water-gate into the lake or across the slightly lower flat twin

bank wall channel, at a dry season minimum of 250,000 imp. gallons/hour 4 (~1.1 ML/h), to a wide single bank irrigation channel (with a fall of 1 in 5,000) and on to the 200 acre (~80.9 ha) irrigation area, finally terminating at the straight property boundary.

Despite losing some potential irrigation area, Yeomans chose this falling single bank

irrigation channel to act also as a conservation channel for an additional irrigation area (see later) higher in the landscape.

The wall access road is on the lake side of the channel (see Photo 3), and rainfall run-off

drains towards the storage. The wide single bank irrigation channel continues this access road on its high side, all the

way to the property boundary and onto the public road. In lieu of an overflow channel from the lake, two flooded water-gates, each 6 foot (~1.8 m)

wide at the end of the 600 yard (~548.6 m) long arm of the storage (parallel to & uphill from the irrigation channel) on the lower side, can release the top 18 inches (~0.5 m) of water back down the plain into the now lower height irrigation channel. The maximum volume available is 135 acre-feet (~166.5 ML), with a flow rate of 750,000 imp. gallons/hour (~3.4 ML/h).

Calculations of claims from the film:

1. In this manner twenty 10 acre (~4.0 ha) bays can be irrigated in one day. With a water irrigation rate of 50,000 imp. gallons/acre5 (~0.6 ML/ha), it follows that: otal ater e ired ater rri ation ate a rri ation rea a otal ater e ired . a . a . w i i ade p o One arter ro t e i er ie i er ater ortion . pl ree arter ro t e a e ie a e ater ortion .

4 Imperial Dimensions are only presented in the film and here use:

Values written as whole numbers and Units written as lower case words, not symbols.

Metric Dimensions follow the Imperial Dimensions in brackets (in most cases) and here use: Values rounded to the nearest first decimal place and Units written as symbols according to the Sy tè e nternational d’Unité nternational Sy te o Unit or SI

Units adopted in Australia. Imperial Dimensions only and format remain in the original photo captions and quotes.

5 Yeomans, P.A. (1965, 1968). Water For Every Farm. Sydney, NSW: The K.G. Murray Publishing Company Pty Ltd. p93

Yeomans, P.A. (1978). Water For Every Farm Using The Keyline Plan. Sydney, NSW: Murray Book Distributors Pty Ltd. p160 Yeomans, P.A. (1981). Water For Every Farm Using The Keyline Plan. Katoomba, NSW: Second Back Row Press Pty Ltd. p160 (each out of print) Yeomans, K.B. (1993, 2002, 2003, 2008). Water for Every Farm: Yeomans Keyline Plan. Southport, QLD: Keyline Designs. p244



v 2.0 4

Checking each of the irrigation flow times:

a i ater ortion Flow i e t al ater ortion ol e

ini ater ortion Flow ate

a i a e ater Flow i e .

. . o r

a i i er ater Flow i e .

. . o r

2. The lake, at eight feet deep, is relatively shallow, but the surface size is such that two

hundred acres of irrigation lowers the lake only a few inches.

t al S r a e rop a . o i le rop t al a e rri ation ol e

a . a e rri ation ol e

t al S r a e rop . .

. . in e 6

3. It (the lake) is fully replenished by the water from the river diversion channel in two days.

The maximum time to replenish ~36.4 ML of lake water is:

a i epleni ent i e t al a e rri ation ol e

ini i er i er ion Flow ate

a i epleni ent i e .

. . o r

6 Throughout for all calculations:

The shorter approximate metric values were used for calculations. In some cases the approximate metric answers were then re-converted back and rounded to whole number

imperial answers. Following the answers, the Imperial Units themselves were re-written as lower case words, not symbols. Inevitably some progressive inaccuracies ensured.



v 2.0 5

For additional Keyline Flood Flow Irrigation higher in the landscape, Yeomans installed a

low lift (4 foot or ~1.2 m)/ high capacity (750,000 imp. gallons/hour or ~3.4 ML/h) pump 500 yards (~457.2 m) along the same long arm of the lake on the upper side.

Photo 4: A site for a low lift pump was selected on the long arm of the lake formed by the old flood channel.7

The 150 acre (~60.7 ha) upper irrigation area can be watered by one man in less than a day.

The Maximum Pumped Water Flow Time is in proportion to the smaller upper irrigation area.

a i ped ater Flow i e . . a

. a . o r

To maximise this higher irrigation area, the pumped water is sent into an upper flat twin

bank irrigation channel following a contour all the way to the same property boundary as above.

This upper irrigation channel also serves as an access road from the property boundary and public road to service the pump.

Both the lower irrigation channel access road and the viaduct wall access road give access to the wall channel water-gate (to select water diversion to the lake or to the lower irrigation bays), the lake water-gates and to operate the pump.


Ltd. (out of print)



v 2.0 6

Photo 5: The three quarters of a million (imp.) gallons per hour discharge from the pump flows into the new irrigation channel.8

The upper irrigation procedure is as follows:

1. The low lift/high capacity pump supplies water from deeper in the lake to the upper irrigation channel and is used in the upper irrigation bays.

2. Any irrigation bay overflow is collected across the access road in the lower irrigation channel.

3. The irrigation bay water-gates are left open for drainage and rainfall run-off.


Ltd. (out of print)



v 2.0 7

Returning to the final calculation of a claim from the film:

4. The three-quarters of a million (imp.) gallons per hour (~3.4 ML/h) discharge from the pump now flows into the newly constructed irrigation channel and irrigation proceeds exactly as before. In the meantime the diverted river flow has raised the lake water level a further ten inches. A peak (dry season) irrigation cycle can average about ten days9 and wit a ‘ pple ental’ reserve (from a dam), reduce this realistically and logistically down to seven days10. Consider for a seven day irrigation cycle, the volume gain or loss ( or ) of lake water: [Each irrigation day (24 hours) runs from 6am to 6am the next day; irrigation times start at 6am] ay Upper rri ation ped o e a e o . . . ay i er ater i er ion to a e ain . . . ay i er ater i er ion to a e ain . . . ay ower rri ation no ain all a e o . . . ay i er ater i er ion to a e ain . . .

otal a e ol e ain or o . The cycle repeats: ay repeat Upper rri ation pin . ay repeat i er ater i er ion to a e all day et

a e ei t ain otal a e ol e ain

a e rea

t en or nit an ellation t e Unit atio i

i ilarly

a t en or nit an ellation t e Unit atio i

a t en

a e ei t ain .

. a

a

. in e

9 Yeomans, P.A. (1965, 1968). Water For Every Farm. Sydney, NSW: The K.G. Murray Publishing Company Pty Ltd. p93

Yeomans, P.A. (1978). Water For Every Farm Using The Keyline Plan. Sydney, NSW: Murray Book Distributors Pty Ltd. p161 Yeomans, P.A. (1981). Water For Every Farm Using The Keyline Plan. Katoomba, NSW: Second Back Row Press Pty Ltd. p161 (each out of print) Yeomans, K.B. (1993, 2002, 2003, 2008). Water for Every Farm: Yeomans Keyline Plan. Southport, QLD: Keyline Designs. p77

10 Yeomans, K.B. (1993, 2002, 2003, 2008). Water for Every Farm: Yeomans Keyline Plan. Southport, QLD: Keyline Designs. p77



v 2.0 8

The lower irrigation cycle is as follows:

1. The river water-gate is opened & the river diversion channel starts flowing. 2. The wall channel water-gate at the beginning of the viaduct wall is left opened and the river

water flows on into the irrigation channel. 3. This irrigation water is supplemented by water from the top of the lake, via the lake water-

gates. 4. The combined water flow of 1,000,000 imp. gallons/hour (~4.5 ML/h) is used in the lower

irrigation bays. 5. Any irrigation bay overflow re-enters the Salée River. 6. The irrigation bay water-gates are left open for drainage and rainfall run-off. 7. The viaduct wall channel water-gate is temporarily closed to divert river water back into the

lake. All steering banks are 150 feet (~45.7 m) apart and run from their respective irrigation

channel down the steepest fall of the plain. Two water-gates, each 6 feet (~1.8 m)11 wide release water into each bay from both the upper and lower irrigation channels.

For geometric consistency and ease of stock movement, P. A. Yeomans recommended that

the steering banks (later fenced) of both the upper and lower irrigation bays be made parallel and aligned. Some minor grading may have been required.

See additionally, the photographic plates in any of these references12, or online: Keyline in New Caledonia (The Nine Photographic Plates from Water For Every Farm) 1965 11 Yeomans, P.A. (1965, 1968). Water For Every Farm. Sydney, NSW: The K.G. Murray Publishing Company Pty Ltd.

p112 Yeomans, P.A. (1978). Water For Every Farm Using The Keyline Plan. Sydney, NSW: Murray Book Distributors Pty Ltd. p176 Yeomans, P.A. (1981). Water For Every Farm Using The Keyline Plan. Katoomba, NSW: Second Back Row Press Pty Ltd. p176 (each out of print) Yeomans, K.B. (1993, 2002, 2003, 2008). Water for Every Farm: Yeomans Keyline Plan. Southport, QLD: Keyline Designs. p243

12 Yeomans, P.A. (1965, 1968). Water For Every Farm. Sydney, NSW: The K.G. Murray Publishing Company Pty Ltd. Plates (without page numbers) 10, 11, 23, 24, 25, 26, 27, 33 & 40 Yeomans, P.A. (1978). Water For Every Farm Using The Keyline Plan. Sydney, NSW: Murray Book Distributors Pty Ltd. p56(2), p145, p146(2), p147(2), p152, p205, (i.e. Plates 10, 11, 23, 24, 25, 26, 27, 33 & 40) Yeomans, P.A. (1981). Water For Every Farm Using The Keyline Plan. Katoomba, NSW: Second Back Row Press Pty Ltd. p56(2), p145, p146(2), p147(2), p152, p205, (i.e. Plates 10, 11, 23, 24, 25, 26, 27, 33 & 40) (each out of print)

http://issuu.com/gboothy/docs/21._keyline_in_new_caledonia__the_n

‘p a yeomans-keyline in new caledonia (20 min) 1965’ (film descriptive paper & calculations)

Documents