The above estimation, concerning summer crops, was based on years of low yields. It is likely that other crops suffered some damage, although the cotton crop was less affected. Public opinion was that the water supply was insufficient.

This deficit was accounted for in the case of Middle Egypt, as shown below. The most significant result of this deficit was the delay in irrigation for the *sharaqi* (summer irrigation), which received very little water before August. This means that some water was available for the period from August to December, whereas it should have been included in the calculation for the period from April to July.

As for the period from August to December, the estimation was based on actual quantities used. This is undoubtedly more than the required quantity, as the farmer finds water readily available and uses more than he needs. Furthermore, a lot of water is wasted.

It was expected that the irrigation system would improve in the future, and that water losses during distribution would decrease. The aforementioned estimation of the total water required annually is unlikely to be significantly underestimated. However, its division between summer crops and Nile crops, as presented here, is not entirely accurate for the desired outcome.

Comparison of Estimations - 6 a) Colonel Cooper's estimation was based on data taken from Giza to the Delta. It is likely that this estimation leans towards conservatism. Mr. Molesworth's and Monsieur Bidon's estimations were based on farmers' desires, and it is likely that they lean towards extravagance. Most of the difference between the two estimations lies in the flood months.

Water Requirements at the Head of the Canals It is observed in the estimations of Messrs. Hurst, Molesworth, Bidon, and Colonel Cooper that the main canals were estimated based on the quantities required in the fields. This was obtained either by consulting agricultural engineers or farmers, or by considering the amount of water lifted by pumps for a relatively small area, then multiplying the required quantity per field by the area of the Egyptian cultivable land to derive the total quantities needed for cultivation. After that, an estimated quantity was added to these quantities to account for water lost during its flow from the main canals to the fields.

Not all water in the fields is drawn directly from the river or canals. Some is drawn through wells from soil moisture. This quantity should not be included in the calculation of the required quantity from the river at Aswan, as it is either originally from water lost from the river or from water previously used for irrigation that has seeped into the ground and joined the subsoil water. It is difficult to estimate the quantity of water drawn from wells, and it may range between 100 and 110 million cubic meters.

During the period from February to July To compare the estimation made by Mr. Hurst, the estimations should account for the quantity drawn from the subsoil during the period of low river levels from February to July, which is approximately 1.5 million cubic meters per year or 1.01 million in the future. This quantity should be deducted from the field estimation of the required water at Aswan, as this quantity is either from the river or canals, or from water previously used for irrigation. It is also noted that the difference of 11.5% found by Mr. Hurst between Aswan and the head of the canals during the low Nile period is partly accounted for by pumps drawing from the river, which is included in the estimation for the fields. In addition, another part of this difference is due to the silting of the riverbed, estimated at about 4% or 5%. The quantity drawn by pumps is estimated at approximately 2%. If calculated according to the number of machines operating on the Nile, the remaining difference of 2.5% is due to water lost and silting of the riverbed.

The estimation of this lost water was based on dry years. In normal years, it is likely that what returns to the river through seepage is more than in dry years, due to the higher water levels in the soil and the higher water levels in the canals.