Agriportal

Request for information Water requirements Diyala

 

Note: This question involves major project planning

Associated Documents:

 Ag Assessment Articleof Diyala Province 6 Sep 07

Irrigation Application Estimates 

 References for Diyala Irrigation

 Water Use Tables

Question:

The Army Corps Engineer is trying to justify if bringing online 24 to 40 stationary water pumps on the Tigris to supplement an irrigation cannel system is justifiable. It needs 12 to 16 Mega Watts of electric power so this is a substantial project under consideration. These pumps are not on the current ministry of water infrastructure systemic. They must be relatively new. For my part the question is do we already have enough water if managed correctly for the entire system.

1. The Agriculture assessment for the Diyala province is still in draft form. But what we have is for a water source is the Diyala River fed by the Hamerin Reservoir.
2. The planned water release rate is 60 cubic meters per sec. starting in early spring and increase to 80 and then 100 cubic meters per sec. by late summer.
3. A footnote stated that no one has seen it reach the 100 cu/m/sec level. The soils being irrigated in the subject area are Vertisols. However some crops are grown in other areas with include Aridisols.
4. The average Max-Min temperature regime e is: Jan 60-50, Feb 63-54, Mar 76-64 Apr 83-73, May 95-84, Jun 106-93, Jul 110-96, Aug 111 – 96, Sep 102 – 87, Oct 92-78, Nov 71-60 and Dec 63-52. Annual rainfall is 4 inches from  Oct-Apr.
5. The crops include both summer and fall crops.
6. The Deputy General for Agriculture’s baseline is 1 cubic meter per second for every 3,300 donums (.25 hectors) for orchards and 1 cubic meter per second for every 7,700 donums.
7. Diyala’s total tillable acreage is: 1,244,876 donums. It is not clear if this includes dryland.
8. Crops based on a 2006 data base are:
1. Citrus 1,999,777 total trees plus 78,788 in propagation Orange trees, lemon grapefruit and narange.
2. Pomegranates 2,460,642 trees plus 141,121 in propagation
3. Grapes 2,154,640 vines plus 92,385 in propagation.
4. Figs 13,270 total plus 486 in propagation. (Note these are really good when soaked in honey!!)
5. Apples I think this is not grown in the subject area, but may require some water from the reservoir. Trees 113,929 Pears 48,352 plus 947 in propagation
6. Apricot 77,521 with 3,705 in propagation
7. Olive 10,392 with 2938 in propagation
8. Season vegetables Eggplant 6,559 donum Pepper 2,063 donum Cucumber 7,475 donum Zucchini 2,967 donum Watermelon 19,155 donum Cantaloupe 1,851 donum Okra 4,058 donum Black bean 3,708 donum Onion 600 donum Bean 1,212 donum
9. Agronomic crops Rice suggested 14,000 donum but in 2006 only 4,860 donum Wheat 457,788 donum Barley 106,675 donum Cotton 6,000 donum Corn 76,920 goal only 42,093 donum planted in 2006 potential is approx. 100,000 donum Soybean – none reported Milo none reported Peanuts 31,105 donum Sunflowers 2,500 donum
9. Livestock assume beef and dairy in the same subject area 139,000 head Sheep goats camel in rangeland Poultry 654,584 chicken 92% turkey, duck geese 8% 37 ponds produced 17,150 of fish

 

Finally a substantial part of the population uses the water in this drainage area. Total population is 1.5 million. Baqubah is over ¼ mil. This looks to be far too hard to make a close estimate. Here is my short method approach.

 

The canal that would fed the supplemental water from the Tigris would benefit about 500 fields a average of 1000 to1200 by 250 to 300 meters in size. This can be read as 50,000 to 72,000 donums, which is based on counting the area from a 1:50,000 scale map. Note all of the land use appears to be vegetables or crops and no orchards were observed in the AO. If one half of the tillable acreage notes is arranged and if this should be the smallest of five irrigated valleys the math is close to reality.

 

Finally the engineer stated that at the weir 20 percent of the water was being diverted into this canal or 12 c/m/s in April 15 c/m/s in Jun and 20 c/m/s by August. The pumping stations are called "Sadism's Gift and the project is "Lower Khalis".  Currently, the amount of water that this pump station can draw from the Tigris is not known. That RFI (request for information) was sent to the Diyala Director General for Water Resources (irrigation) but no response. More important, the Dam that Turkey is building on the Tigris, which may reduce the flow of this river by 50%. Clearly this is a major Water management engineering issue at the Ministry level for Iraq.

 

It is hard to estimate the potential flow of the pumps that are on the Tigris because we still do not have the level that the pump manifold reach into this river. The pump capacity should exceed what is currently able to be utilized. People believe that only the lower Khalis will be supported by these pumps. The water saved would be used by the upper Khalis or more would be diverted to the four other principle canals.

 

All canals at this site start just below the dam. Orchards are close to the Diyala River while Khalis have few orchards only. Water requirement for normal crops is one cubic meter for every 7,700 donums. There are two pump houses. The first (South) has 24 pumps and the second one (North) has 19 Pumps that are slightly smaller.

 

 

Response:

 

Based on the data you sent plus some of my experience, I would estimate the required canal capacities in the Diyala area as follows for each 100 hectares.  You can convert to whatever you think in the actual area.  I am not sure what the conversion is between dunams and hectares.  Cms/1000 ha, Jan 0.4 Feb 0.42 Mar 0.81 Apr 0.97 May 1.34 Jun 1.63 Jul 1.78 Aug 1.71 Sep 1.29 Oct 0.92 Nov 0.47 Dec 0.38

Somewhere I read that the 1950 census of agriculture showed the lower Diyala area serving about 32000 ha of irrigated land.  If this is the case, the capacity of the canal system based on July demands would be about 56 cms.  I have not visited Iraq for about 20 years, but in my opinion those canals are very unlikely to have the original capacities due to poor maintenance over the last few years. 

 

1.  The general definition for a donum is 4 donums = 1 ha (hectare). 

2.  On the baseline of 1 m3/s per 3300 donums (or 330 ha by the above definition), this amounts to about 1 inch per day for orchards and similarly 2 inches per day for other crops.  Even considering conveyance losses in the canals, this would be adequate.  (Note: assuming a 24 hours day - if they divert or pump less than 24 hours a day, then this affects the calculations).

3. Based on estimation from the map, the total command area of 500 fields (1100 m x 275 m) is about 15,126 ha.  If the total water supply is 80 m3/s, then this provides 1.8 inches per day (24 hours) or 0.9 inches (12 hours) - plenty of water.

4.  not sure what "the weir at 20%" means.  If this means that you get only 20% of the water to the command area, assuming 20% of 80 m3/s, this provides 0.37 inches per day.  Assuming 50% losses, the this provides only 0.16 inches a day - not adequate for this size of an area.

 

Based on the goat and sheep specialist for A&M, 150 lb ewe would require 1 to 2 gallons of water per day.  As the temperature increases, the ewe would drink more water and would be closer to the 2 gallons per day.