Another condition by which floods are greatly aggravated is the obstruction of the channel by insufficient bridge openings and other structures. The cause may be ignorance as to volume of flood run-off, or in the struggle to realize a large ultimate income from a small present investment the possibility of occasional damages may be carelessly disregarded. This encroachment on the channels of streams should be a matter for official regulation, and deserves more public attention than has yet been given it in this country.
Perhaps the complication which involves the most difficult problems of construction and operation of flood-control works is that of combining adequate flood protection with equalizing of stream-flow for the development of power and other purposes. To materially ameliorate flood conditions on large rivers usually requires the provision of an enormous amount of storage; logically, the larger the proportion and the greater the capacity, up to a certain limit, the better the control. On many streams it is doubtless feasible to build systems of reservoirs which would entirely do away with destructive floods, provided the reservoirs be intelligently operated solely for flood control. It must be frankly admitted, however, that the ideal use of storage for flood control is not entirely consistent with the best use of the same storage for equalizing the flow throughout the year. For the purpose of ideal flood control, the reservoirs should be emptied of accumulated flood waters immediately after the flood has subsided and as rapidly as possible without swelling the stream to dangerous proportions, in order to have the storage available for another flood. On the other hand, for the purpose of equalizing the flow as completely as possible throughout the year, the reservoirs should only be drawn upon when necessary to supplement the natural flow in the stream in order to maintain the desired average flow. Theoretically, if the extremes both of the rate and volume of flow of the stream can be determined (which usually requires very long records of discharge), and if sufficient storage be provided for the absolute equalizing of the flow, the solution of both problems would go absolutely hand in hand, and flood control by storage would be synonymous with ideal equalization of stream flow. The most practical solution, where conditions will permit, seems to be to provide an excess of reservoir capacity so that the portion of the reservoir above a certain elevation may be reserved entirely for flood control while the portion below that elevation may be used for equalizing the flow of the stream. This plan has been proposed by the Commission in the case of the projected Portage reservoir on Genesee river.
Undoubtedly the greatest economic problem involved in a study of flood control is that of the adjustment of the relative rights of the residents of the upper and lower sections of the river valley. From the point of view of each the matter calls for different modes of treatment. The up-river resident believes the solution of the problem will be found in facilitating the passage of the flood by his district. This may result in discharging a great volume of water on the communities down-stream at a time when it would swell the crest of the flood in that section. The down-stream resident naturally has to contend with a much larger volume of water, so that to restrict it to a channel of moderate dimensions is out of the question, and he therefore prefers an arrangement whereby the surface waters from the upper stream may be at least temporarily stored in the basins containing the lands of his up-stream neighbor. The Water Supply Commission has held that the proper disposition is the improvement which will work the greatest good to the greatest number, provided there is a distinct economic advantage to the community in the river valley as a whole.
The matter of municipal water supply is likely to be involved in some of the great storage projects, also the water supply for the canals of the State. Several streams on which water storage is practicable are at present or will be in the future used as sources for canal water supply. The plans contemplated by the Commission would result in insuring the sufficiency of these supplies, but the uninterrupted maintenance and protection of a constant water supply during the navigation season is undoubtedly essential to the proper operation of the canal system. In these times of extensive municipal water supply systems, it seems reasonable to assume that there may be instances in the practical working out of a comprehensive plan of water conservation where the project of water supply for a municipality or group of municipalities may be combined with a water-storage project to good advantage. At any rate the careful and prolonged study which has been made of municipal and domestic supplies by the Water Supply Commission has given it a full appreciation of their prime importance, and the Commission believes that in any water-shed the question of municipal water supplies should be given first consideration.
It has been believed by many that the State, in the exercise of its police power, could construct storage reservoirs which involved the use of some of the State's forest lands in spite of the constitutional provision that "The lands of the State, now owned or hereafter acquired, constituting the Forest Preserve as now fixed by law, shall be forever kept as wild forest lands," and that "They shall not be leased, sold, or exchanged, or be taken by any corporation, public or private, or the timber thereon be sold, removed or destroyed." The River Improvement Commission considered the constitutional question thus involved, and reached the conclusion that the force of this prohibitory clause in the constitution was paramount to all exercise of the police authority of the State to protect the public health and safety, and it declined further to consider any petitions involving the utilization of State forest lands for the construction of storage reservoirs. The Water Supply Commission has held practically the same view of this question and has accordingly recommended to the Legislature that the Constitution of the State be so amended as to permit the flooding of State forest lands for the purpose of constructing storage reservoirs which are to be forever owned, maintained, and controlled by the State for the public use and benefit and for the purpose of providing a public revenue.
The conservation of the water resources of the State on a broad and comprehensive basis, which shall give practical consideration to the most favorable natural opportunities and produce the most beneficial results necessarily involves the flooding of relatively small areas of State forest lands in the Adirondacks. The surveys indicate that 55,000 acres of State land would be required for a complete system of water storage, including many reservoirs likely to be built only in the distant future, if ever. Even this total of 55,000 acres is only 3.9 percent of the State's holdings within the boundaries of the Adirondack Park; of this amount about four-fifths is low swampy land or is under water, and only one-fifth, or eleven thousand acres, is of any considerable value for forest purposes. This question of the amendment of the Constitution is under consideration by the State Legislature.
The drainage of swamp lands is another problem which tends to complicate rather than simplify the water-storage situation. There are within the State extensive areas of swamps whose owners would like to have them drained and reclaimed for agricultural purposes. Some projects of this character have already been carried out, but the questionable constitutionality of most drainage laws has interposed to retard any very widespread reclamation movement of this character. Here again the desires of the up-stream and down-stream residents do not harmonize. The down-stream riparian owner, especially if he operates a water-power, objects to the drainage of those marsh lands on the ground that they constitute a natural storage reservoir which operates to steady the flow of the stream. His solution of the problem would be to build dams across the outlets from these great swampy tracts and thus increase their capacity for storage. In some instances it appears to be entirely feasible to do so, while at the same time it seems equally practicable to secure the necessary storage by raising the surface of some existing lakes and subjecting them to some fluctuation. The question enters as to whether it is not better to flood a comparatively small additional area around the shores of existing lakes in order to secure the required storage and then drain and reclaim swamp lands for agricultural purposes.
By special act of the Legislature in 1909 the Water Supply Commission was given jurisdiction over certain local improvements to streams which contemplated the betterment of both the sanitary and scenic conditions. Certain lakes in the State are bordered with large areas of unattractive swamp and stump land which the local residents would prefer to have permanently submerged. It is claimed that the scope of improvement would include not only benefits to the conditions affecting the health of the community, but that such improvements would in a number of instances result in rendering the region more attractive, especially to summer visitors seeking recreation and health. It is also pointed out that in some instances the interior navigation on some of the lakes would be materially improved, and that the community would materially benefit from the improvement in this manner. The State has already carried out some improvements of this nature, and it seems quite probable that there are possibilities of a number of similar improvements. The problem does not appear to enter into the larger storage reservoir projects, and has not been given very extended consideration by the Water Supply Commission.
New York State and her citizens are justly proud of her scenic falls. Of these the American Falls of Niagara are doubtless the most widely known. There are, however, other falls on streams within the State which constitute local attractions of great interest in their respective communities. The Salmon Falls on Salmon river in Oswego County, the series of falls in Letchworth Park on the Genesee, and High Falls on the Ausable are prominent examples. The Water Supply Commission entertains a deep appreciation of the esthetic value of these beautiful masterpieces of the hand of nature, and believes intrinsically in their preservation. This attitude of the Commission is exemplified in the plans for the proposed Portage Falls power development, which provide for a flow greatly in excess of the minimum flow over the falls for a period of twelve daylight hours in each day. On the other hand, the Commission sees also the wonderful amount of quiet comfort which would be afforded to modern civilization by electric light and the many other applications of power which can be generated by the waters running over some of the falls of the State. The major part of the surplus water is wasted in the spring months of the year, and does not contribute in any appreciable measure to the scenic beauty of the falls; on the other hand, the natural flow of the streams frequently is reduced to such a low rate that the falls lose something of their attractiveness. It will doubtless prove practicable in connection with power developments at some of the naturally attractive falls in the State to insure a larger minimum flow in the dry weather as well as to conserve the great amount of power at present running to waste over the falls in the wet season.
In humid climates irrigation is admittedly more or less of an experiment. Its financial feasibility seems to depend on its being considered a matter of insurance against the failure of crops in seasons of low rainfall. There have been a number of scattered experiments carried on at different places in the State, but the plants used, especially in the older experiments, were comparatively complicated and expensive. The equipment for one particular set of experiments cost about $500 per acre. More recent experiments have been conducted in sections of the State where the precipitation is light during the growing months, and in fact throughout the year, and with a less expensive and a more generally practical equipment. In a few instances, which have been brought to public attention, the experimenters have been able to raise excellent orchards and garden products by means of a comparatively inexpensive irrigation plant, whereas other portions of the gardens and orchards of the same farms did not produce results nearly as satisfactory. One successful experimenter claims that he has made 20 percent interest on his investment by the installation of a small irrigation plant. The precipitation records show that there are portions of New York State where the rainfall during the crop-growing months does not amount to more than one-fourth or one-fifth of the water which is applied to the same crops where irrigation is conducted on a broad scale. The subject has not been entered into in great detail by the Water Supply Commission owing to the fact that its statutory jurisdiction does not seem to justify such a study, but it appears that the possibility of such use of at least a portion of the water supply of the State should be borne in mind and its development carefully watched in connection with the formulation of a general plan for the conservation of the water resources of the State by means of storage reservoirs.