The Dikes of Holland 



an area of 417 square miles, it is esti- 

 mated consume annually no less than 90 

 millions of cubic meters of water from 

 adjacent rivers. 



The climate of the Netherlands pre- 

 sents therefore an interesting anomaly. 

 In spite of its small rainfall it does not 

 exhibit any of the characteristic features 

 of a semi-arid country, with the excep- 

 tion of some sandy, barren areas which 

 are incapable of producing anything 

 and are actually to be classed as desert 



Norm al Monthly .Precip.talion .n Inches , 



j|f|m|a|m|j|j|a|s|o|n|D 



AMSTERDAM 

 Period : 



OMAHA 



Period: 

 27 years 



Normal . 

 31 >* inches 



SACRAMENTO 



Period . 



47 years 



Normal. 



34.8 inches 



WASHINGTON 

 Period: 



m i l l 



■■■i l ll lii .. 



te 



Mm 



lands. Though an equal annual rain- 

 fall in the Great Plains region is not 

 sufficient to produce forest growth, the 

 Netherlands were practically entirely 

 forest-clad at a period not so very re- 

 mote, and probably would be so now 

 but for the deforestation which has nat- 

 urally attended its settlement. This 

 anomaly is easily explained by three fac- 

 tors : the consistency of the Dutch soil, 

 which renders it capable of absorbing 

 and holding large quantities of w^ater ; 

 the inexhaustible perennial streams and 

 other bodies of water that feed it, and 

 last, but not least, the even distribution 



of the rainfall throughout the year. 

 The lack of ample precipitation is thus 

 more than offset by the humid condi- 

 tion of the soil, which makes aridity 

 impossible. 



After reviewing all the difficulties and 

 perils with which the Hollander has 

 had to contend in the building up of his 

 country, it at first sight appears strange 

 that he should ever give up any portion 

 of his valuable lands to the dangerous 

 element that he has for centuries fought 

 so desperately. But as in the course of 

 the history of every nation it sometimes 

 becomes necessary that the welfare of 

 one or more individuals should be sacri- 

 ficed for the good of the country or of 

 the world at large, so there are times 

 when the people of the Netherlands do 

 not hesitate to cause large areas of land 

 to be inundated in order to save what 

 is dearer and more valuable. Recourse 

 is had to such practice during the season 

 of high waters on the rivers and also 

 during times of war. 



MEANS OF PROTECTION AGAINST 

 FLOOD DISCHARGES 



The rivers that flow through the 

 Netherlands, like most streams of the 

 northern hemisphere that flow in a 

 northerl}^ direction, are subject during 

 the earl 3^ spring months to ice jams and 

 sudden flood discharges along their 

 lower courses — a condition well nigh 

 inevitable, as their waters flow from a 

 warmer to a colder climate. In the 

 Netherlands the Rhine, owing to the 

 many channels into which it divides, can 

 be controlled with far greater security 

 than the Meuse, which, though a much 

 smaller river, has a greater fall, and in 

 its narrow, tortuous bed becomes when 

 swollen a source of great danger, threat- 

 ening to overtop its dikes. Sandbags 

 and the many other devices employed 

 so extensively in similar cases of emer- 

 gency along the Mississippi levees are 

 then used, but the most efficient relief 



