Water Supply Verdun North-East Quadrangle 1-50,000
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TITLE PAGE TITLE Water supply Verdun north-east quadrangle 1-50,000 TITLE TRANSLATION AUTHOR PUBLISHER .E.F., G.H.Q YEAR 1918 550—G. S. Schs., Fort Leavenworth—11-29-27—5M - : ;^v^;s. SE< PREPj EF ENGINEER W WATER SUPPLY VERDUN NORTH-EAST QUADRANGLE X 1-50.000 ^ • i \ .s .J3 _, g r i L • •JU^^J D TO noo;.j ic " !«.s?ificatior. or-s. iiif-j it v PRINTED AT THE BASE PRINTING PLANT 29TH END, U. S. ARMY 1918 6. H. Q.. A. E. F. SECOND SECTION, GENERAL STAFF PREPARED IN OFFICE CHIEF ENGINEER WATER SUPPLY VERDUN NORTH-EAST QUADRANGLE T-5O,OOO PRINTED AT THE BASE PRINTING PLANT 29TH ENG., U. S. ARMY 1918 WATER SUPPLY VERDUN NORTH-EAST QUADRANGLE 1:50,000 INTRODUCTION The sources of water within the Verdun N.-E. quadrangle are (1) surface water; (2) shallow wells; (3) springs; (4) drilled wells in hard rock. Before the war the civilian population was largely supplied with water from springs and shallow dug wells. Springs are fairly abundant in the quadrangle, and occur along certain lines determined by geologic formations. Dug wells are chiefly confined to valley bottoms, and are found in nearly every town and many farm houses. So far as known, no important use has been made of the surface water, though there are many streams, in addition to the Meuse River, which carry considerable water throughout the year. This water is, however, not potable. No records have been found of any deep drilling within the quadrangle, though there are known to be water bearing horizons in parts of the region. The distribution and quantity of streams, springs and other underground water, are in a large measure determined by the physical features, including both surface terrain and rock formation, as well as by precipitation and evaporation. It will be desirable, therefore, to briefly describe these physical features before the data on water are presented. PHYSICAL FEATURES An upland, characterized by flat or rounded summits and diversified by many valleys having gentle slopes, occupies the larger part of the quadrangle. The western part of this upland is made up of a series of rounded hills and interstreamed areas, whose summits mark a gentle undulating surface. Here the valleys are shallow and their floors merge gradually with the gentle hill slope. The rather even summit level is broken by small nobs and ridges, which stand higher than the general upland surface. Much of this western part of the quadrangle is underlain by hard limestone, covered usually with less than a meter of soil and weathered rock. The higher nobs and ridges west of the north and south line No. 301, are composed of chalk, with some soft sandstone, which rests on the limestone. These formations yield firm, well drained ground. Springs occur along the outcropping margins of the sandstone. A clay formation skirts the southwestern margin of the quad rangle. Its northern boundary is an irregular line running in a general westerly direction from Nantillois, and including the head 2 VERDUN WATER SUPPLY water of the Andon Ruisseau, and the valley of the Exermont Ruisseau. This clay belt offers soft ground, except during dry seasons. As far west as the north and south line No. 308, the clay- is capped by limestone, which forms a steep bluff along the upper valley walls. West of this line, chalk overlies the clay and forms the higher part of the upland. The upper contact of the clay and limestone, or clay and chalk, is marked by a line of rather strong springs. Tracing the upland to the north-east it becomes less broken by valleys as the Meuse River is approached. Here it is marked by broad, flat-topped, interstreamed areas having a general accordance of summit levels, and is, indeed, a dissected plateau whose surface slopes gently to the west and south-west. The Meuse Valley, in most places steep walled, is commanded on either side by the margins of the plateau standing 60 to 100 meters above the valley floor. East of the Meuse the plateau feature (Cotes de Meuse) is still more marked, and finally ends in a scarp (40 to 60 meters) from the foot of which stretches a gently rolling lowland (Woevre). The upper part of this scarp, made up of limestone, is steep; the lower part, underlain by clay, has a gentle slope. It is the most striking topographic feature of the region. The margin of the scarp is scalloped by a number of small valleys, and some still greater irregularities are introduced by isolated mesas, whose summits carry the plateau level well out into the lowland. The largest of these is the long, flat-topped ridge (Cotes St. Germain) north of Murvaux, which commands the adja cent lowland, and Meuse Valley. The plateau bordering the Meuse Valley on both sides is chiefly underlain by hard limestones, with here and there some shale beds. This limestone usually occurs within a half meter from the surface and is covered by a clay soil and sub-soil. The surface of the pla teau is fairly hard, well drained, and easily traversed. Where the limestone rests on clay, springs occur, notably along the eastern scarp of the plateau. The scarp bounding the plateau on the east is traced as an irregu lar line northward from near Crepion to Breheville, then turns westward, and at Sassey merges with the valley walls of the Meuse River. Beyond the Meuse it is continued to the margin of the quad rangle near Halles. East and north-east of this line is the Woevre Lowland, in places swampy, but generally with sufficient relief to be fairly well drained. Here the summits, rounded ridges and nobs stand from 20 to 40 meters above the valley floors. The formation of this lowland is clay shale, which also occurs in the lower gentle slope of the scarp, the overlying limestone forming a steep bluff or cliff. This clay shale weathers to clay, and PRECIPITATION 3 the formation being impervious, all water is held at the surface. Therefore, soft ground is to be expected in the lowland area. Much of it, however, has sufficient relief to be fairly well drained, except during the rainy season. In general, the lowland is difficult to traverse, except during the driest season. There are no springs in the clay area. To the north-east, the lowland merges with the lower slopes of a gently rolling upland. This is made up of limestone and some clay shales. In general, the surface is firm and well drained. Some springs occur in this region. PRECIPITATION The mean annual precipitation varies from about 1000 mm. (39.4 inches) on the higher parts of the upland to 729 mm. (28.7 inches) in the Meuse Valley and 682 mm. (26.9 inches) in the Woevre Lowland. There is an average of about 800 mm. (31.5 inches) over the entire quadrangle. No data has been found on the monthly precipitation on the plateau, but the following table gives the record at Don-sur-Meuse, which is probably typical of the Meuse Valley. The percentage of the total annual precipitation during each month is also included in this table. MONTHLY PRECIPITATION, DON-SUR-MEUSE Precipitation Percentage of Total Annual Millimeters Precipitation January 58 7.9 February 42 5.8 March 48 6.6 April 45 6.1 May 53 7.3 June 71 . 9.8 July 71 9.8 August 68 9.3 September 63 8.7 October 79 10.8 November 66 9.0 December 65 8.9 TOTAL ANNUAL 729 mm. (28.7 inches) The above table shows that nearly 30 per cent of the rainfall falls in the summer months. From the standpoint of runoff, the large summer precipitation is neutralized by the evaporation. Dur ing the hot months the evaporation exceeds the precipitation. The rainfall decreases from July to September, and greatly increases in October, the wettest month of the year. In June and July rainy days are frequent, but hard rains unusual. August is characterized by few rainy days (7 to 10), but by heavy storms. In September and October the rainy days average 8 to 10 in each month, and 4 VERDUN WATER SUPPLY heavy rains are infrequent. Of the winter months January has the greatest percentage of days with some precipitation, and February the least. Snow storms are likely to occur in the months between December and March, inclusive. The heaviest snow fall is in January. January is the coldest and July the warmest month of the year. It is probable that the greater precipitation on the plateau, as compared with the valley, falls during the nine coldest months, and that the rainfall during the summer is about the same in both provinces. SURFACE WATER The volume of streams is determined chiefly by the amount of precipitation and evaporation, and these, as shown above, vary greatly during different seasons of the year. It is also affected by the surface terrain, and by the permeability of the soil, distribution of springs, etc. In areas where the surface formation is clay, the precipitation runs off quickly after a rain, unless this has been preceded by a long drought. The streams, therefore respond quickly to a rainstorm, and also fall rapidly after the storm is over. There are also few or no springs in the clay or clay shale regions. Under these physical conditions the stream volumes vary greatly from time to time. If the country rock be limestone, or interbedded limestone and shale formation, much of the rainfall is absorbed by the soil and sub-soil to emerge as springs and seepages at a lower level.