50 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Feb. 3, 



THE DRAINAGE OF THE COUNTRY. 



By W. MULUNGAR HiGGiNS, Esq., C.E., &c., formerly Professor of 

 Experimental Philosophy at Guy's Hospital. 



During the nest three or four years there will probably be such an 

 opportunity of improving the internal resources of the country, as has 

 never before occurred. It is generally understood that the Govern- 

 ment intends to introduce, during the next session of Parliament, a ge- 

 neral measure, whicli will, probably, embrace the sewage of towns and 

 the drainage of the land. That sucli a measure, wisely planned and 

 carried out with skill, will be an invaluable boon to the nation, every 

 one admits ; but it may be doubted whether the public is at all aware 

 of the extent of its value, and perhaps not many of its most sanguine 

 promoters. The health of the population in towns, and the improve- 

 ment of cultivated lands, are the two results which are generally ac- 

 knowledged ; but the effect of a good system of drainage will be 

 scarcely less beneficial to the internal navigation of the country, than 

 to the agricultural condition of the lands whicli are now, or may be. 

 brought into a state of cultivation. This view of the subject is so 

 important, that a few remarks may not be inappropriate in the present 

 state of the question. 



There are numerous rivers in this country vthich would be of im- 

 mense value to the districts through whicli they flow if thev were 

 navigable, and would become competitors with the railways for the 

 carriage of niPrchandize, and the transit of passengers. Many of 

 these have been at former periods large and deep rivers, and have 

 carried vessels of considerable burthen. By great ignorance, or want 

 of attention, and small temporary expenditures, natural causes, which 

 man ought not only to control but to render subservient to the accom- 

 plishment of his objects, have, in various ways, so changed their 

 former condition, that tliey are not only altogether useless for naviga- 

 tion, but are scarcely sufficient channels for the drainage of the country 

 through which they'lazily flow. As soon as the commercial wants of 

 some'town situated on or near their banks demand a rapid and_ com- 

 modious transit by sea, an engineer is required to give his opinion as 

 to the method of improving the river; dredgings and embankments 

 are immediately commenced, and the strpams which had before only 

 tended to the destruction of the channels, are made to assist in their 

 excavation. The difllculty and expense which attend these local im- 

 provements, are only known to those who have been engaged in con- 

 ducting or performing them. And aftpr the expenditure of millions 

 in various parts of this country, during the present century, the good 

 which has been effected is confined to a few districts, and is not appre- 

 ciated, if in any degree felt, by the country at large. 



Should a general plan of drainage be adopted, there will be an op- 

 portunity of improving, and perhaps rendering sufficiently navigable, 

 every river in the kingdom. They are the natural and proper channels 

 by vvhich all the waters that fall on the surface of the island should be 

 conducted to the sea. In the present state of the country, these waters 

 are allowed to lie upon cultivated lands, to be evaporated by the heat 

 of the sun, or to collect in low lands, forming bogs and marshes. But, 

 carry them by a perfect system of drains into the rivers, and with a 

 little assistance thev will deepen the channels, and improve the out- 

 falls. 



It is not ray intention, at present, to enlarge upon this subject, as I 

 may, at some future time, offer a few suggestions upon the manner in 

 ■which this drainage, as a national measure, should be performed, and 

 take a more enlarged view of the benefits that may be obtained. The 

 importance of the measure, however, will entirely depend upon well 

 devised plans and careful execution. The subject is one almost un- 

 known to a large number of engineers, and there is no work in the 

 language which treats the subject systematically. My attention 

 has been many years directed to this and similar pursuits, but although 

 I could mention many admirable reports delivered by British engineers 

 during the last two centuries, in wliich the great principles of drainage 

 are fully enforced for particular localities, 1 do not know of any paper 

 containing so excellent a practical view of the subject as is given in 

 one chapter of Gughehnini's work on rivers, i have, therefore, 

 been induced to offer a translation of it. The Italians still look to the 

 writings of this great man as authorities on all questions relating to 

 the motion of water, and although in some particulars he has erred in 

 judgment, the credit given to him by his countrymen can scarcely be de- 

 nied by us, notwithstanding the advance tli.it has been made in both the 

 theory and practice of liydraulic engineering. It is at present uncer- 

 tain to whom may be intrusted the works necessary for carrying out 

 the intentions of the Government, hut 1 have no hesitation m saying 

 that a careful study of the following pap^r, considered in connexion 

 with the works which have been jicrformed in this country, particularly 

 in the Fens, may be the means of preventing many errors that would 



be fatal to the success of the plans, in the ever varying conditions of 

 the districts in which the iiniirovements are to be made. It is with 

 the view of assisting those who may be thus employed, and the agri- 

 culturists who are attempting to secure the effectual drainage of tlieir 

 particular districts, that I have made the following translation. 



Beside the large rivers, which have their origin in high mountains, 

 and the torrents which, although they are not fed bv s|irings, have 

 also their birth in mountainous districts, there are channels which carry 

 rain water only, and these commence in the plains. They have seldom 

 if ever been formed by nature alone, but by the art of man, who, to 

 drain his fields and render his ground fit for cnllivation, has excavated 

 ditches, into which the rain water immediately flows, and these uniting 

 with others, are finally discharged into a common bed, formed by 

 manual labour, an<l called a drain,' or by other names, according to 

 the custom of the country, and such drains have their own proper 

 names, in the same manner as rivers. Jlost of these drains are public 

 property, because the right of introducing the rain water into them 

 is comrnim to many, and by their channels the united waters flow 

 towards their outlet. It happens, however, that some fields have no 

 need of the public drain to keep them dry, and these are they which 

 are contiguous to rivers properly embanked, into which, by means of 

 private d'itches, their wateis are introduced; but these do not need 

 any explanation, as they are but few, and nature herself teaches the 

 mode of managing them. 



The declivity of pi dns is generally so small, and the surface so iin- 

 equal, that it is not possible for the rain water, unless it moves with 

 great impetuosity, to run off from the high to the low lands, and leave 

 the fields in a state of perfect cultivation, particularly in the time of 

 spring and summer, when the grasses greatly impede its discharge. 

 It is true that the waters are ultimately united in \ov/ places, and 

 leave the higher free, but it is also true that for this end a long time 

 is necessary, during which the earth, imbibing an excess of moisture, 

 becomes barren; and as there are in the plains, low places shut up on 

 all sides by more lofty grounds, the water is collected in them, and 

 not being able to escape, necessarily forms a marsh or bog, as frequently 

 occurs in countries unoccupied or neglected by man. Tliis has made it 

 necessary for civilized n.itions to cause all the plains to he connected by 

 excavated ditclies, and to direct the outlet of these ditches to the 

 places where experience has proved they may find basins or continued 

 low grounds, and along these to excavate a capacious canal to receive 

 the atmospheric water from the drains of the country. From this 

 artifice arose tiie drainage of all the provinces, which have been 

 brought into a fertile state, but they can only be kept in that condi- 

 tion by the preservation of the first excavations. 



These drains have their termination, either in neighbouring rivers, 

 in marshes, in ponds, or in the sea. Those that discharge themselves 

 into rivers can serve only those fields that are at least higher than 

 their beds, if temporary, or than the lowest surface of their waters if 

 permanent. The mouths of drains, where they discharge themselves 

 into a river, mav be either open or closed. Those only can have their 

 mouths free, that is open at all times, which have their beds higher, 

 or at least as high, as the greatest flood of the river, for othervvise, if 

 the river be turbid, regurgitation through the drain would stop it with 

 deposits, and close the outfall; hence it is that only higher grounds 

 can be drained bv open conduits in rivers. But if these channels 

 are embanked, (a certain evidence that the flood rises over the surface 

 of the country,) it will not be possible to have the mouth always open, 

 but some mechanical arrangements will be necessary to prevent tlie 

 floods of the river from being introduced into them, and that the rain 

 waters, if there are any, should be retained either in them, or in the 

 ditches of the fields, until after the flood has subsided, when the 

 impediments at the mouth may be removed, and the water dis- 

 charged. 



Many artifices have been adopted to prevent the regurgitation of 

 rivers 'in drains; but this is not the place to speak of them : they 

 may be seen in Baratteri's " Architettura dell'Acque," part I, lib. 8, 

 cap. 19. The most common are the beloie mentioned. We should, 

 however, in these cases, carefully observe the conditions of the 

 districts, which give occasion for as many rules. 



1. If the lands which are to be drained 'by ^ '^'i^""^'''^"'"'^'"''' ""''' ^ 

 gate, are on the same hoi izontal plane, it is not necessary that the sides 

 of the conduit shiuild be embanked ; because when the gate is closed 

 the water is unable to overflow any one part, or if through loo great 

 an abundance it should overflow a part, it will distribute itself equally 

 over all the country, an effect embankments could not prevent, which 

 are therefore of 'no utility; but if the inundation of the country 

 should not be prevented, (in case the gate should break, an accident 

 very rare,) other cautions will be demanded. 



1 Scolo, fossa di scolu, tundotto, tralturo, discuraorio, o in allra maiiiera. 



