The Montgomery advertiser., 1901-11-17
FORECASTING. FLOODS;
 HOW THE WORK IS DONE
Value Of the Weather. Bureaus River Service to
 People Who Live Along Alabama Streams.

1 The importance and value of tho river l and flood service of the Weather Bureau
 is doubtless but little understood by | many persons who do not live near some | river, the fluctuations of which vttally | affect their interests or their personal | cqgnfort
 Gp to a few years ago. it was no un- ! common event for a surging Hood to sweep down our large rivers, without warning. leaving devastation and often or ten years, however, thanks to tke thorough and beneficient hood service of the Weather Bureau, few, If any, serious hsvs n any o 1ns ing heralded well in advance Of the flood CT est. and the money value of this fca- ture of the Bureaus work in some one locality is often many times greater than the entire annual expenditure tor It's maintenance.
 In fact, on several occasions authentic reports collected after freshets in the Ohio and the Missouri or Mississippi riv- CTS has proven that the value of goods saved from a single cellar in one of the large commercial centers on these Water wayr, has been more than the annual cost or the entire river service of the co uhtry.
 The great value of this service has in the past eight or nine years been re- peatedly demonstrated by the timely warning of freshets in the rivers of Ala ba t.a Indeed, it is ascertained from the records of the Weather Bureau that not a single freshet has moved down the G osa or Alabama in the past eight yeats. without being preceded by warn ings from two to f)Lr days in advance of the flood, and that, during that period, as far as can be ascertained very little cts in these rivers that any warning could avert.
 Section Director Talks.
 It is often a matter of surprise to those
 unacquainted with such matters that the flut tuations of the rivers can be go accurately determined. The matter is considered of such general public inter- est particularly in view of the approach ing winter, or freshet season, that the following information on the subject has been elicited from Section Director Chaf- fee, of the local office of the Weather Bureau, who has charge of the river and flood service in this section. and who has e,inced such a keen interest in bringing this phase of the Bureaus work 1T. this region to its present high stand- ard.
 "The Weather Bureau maintains a numoer of river stations on the Alabama and tributaries from Resaca and Canton, Ga., on the OoStanaula and Etowah, and ali lssee on the Tollapoosa to Selma on tha Al ,bama he said At all these St tlt,ops the stagl of the water is ob- sarss1 on a graduated gauge at very nearly the same Et UT: this information, together wita ti.e fact that the river Is either sta,'cnary. falling or rising at the time of the observation, and the pre- yd;ling wind d drtttion and weather at ths san,e time, With the total rain or sn 1w fall during the previous twenty-four hours, is tGit SraE. cd to the Montgomery office, where, after being charted, 1t shows an almost instantaneous survey of the water levels of the entire system, with the amount of rainfall, if any over the drainage area and its effect upon the
 Each forecaster is familiar with the nns f,~, io1h hn rn. ports, the topography of the country and
 the permeability of the soil. A slow rain of considerable volume, on a nearly level and permeable soil, especially after prolonged drought, has but little ef- feet on the riverS; so in summer, when large portion of the drainage area is ubder cultivation and the soil loose and
 pe-meable, a general and heavy rain does not have near the effect on the river level as in winter. when the fields are clear and the soil hard. Then, again, the incline of the watershed is one of the important factors in calculating river changes.
 owing to the impermeable nature of the soil and the incline of the watershed tenn Northeastern Alabama and North western Georgia. one inch of rain in that section has as much effect upon the middle and lower rivers as would two middle section, where the soil is more permeable. or six inches in same time in the southern section where the ground Is quite absorbent.
 The Alabama's Floods.
 "The effect of heavy fainfalls over the area drained by either of the tributaries of the Coosa is usually felt quickly in the upper Coosa, but the most dangerous condition for the upper Coosa is gen eral and excessive rain falling at the same time over the areas drained by both these tributaries: for then the vol ume of water rushing into the Coosa pro Rome and for some distance below. The drainage from the Tallapoosa into the Alabama is also very rapid. as implied by the Indian meaning of the word Tai this section, freshets that occur in the as a rule, run into the Ala bama and flow off before the full effect of the inflow from the Coosa is felt; oc- Coosa is felt in the upper Alabama about the same time that more recent rains bring in a freshet from the Tallapoosa' in such a case. dangerously high waters may occur from Montgomery to Selma and a dangerous back water stage be caused in the lower Coosa. --,,
 There are many factors to be consid- cred in river forecasting, especially in the rivers of this section, which rise and fall so rapidly. but experience, which is the best teacher in nearly all phases of work, plays really the most important part here Constant association with the river changes from day to day and season to season equip the forecaster for his work, though certain rules which he may formulate from number of years record prove helpful.
 'As a rule. the most dangerous and sudden rises in the rivers of this system are caused by the excessive precipitation associated with decided atmospheric de- pressions which develop in Texas and move rapidly eastward over this region or immediately north of 1t.
 "During rain periods the rivers are closely watched and special reports from the river stations called for several times each day: in this way the effect of the rainfall and movement of the freshet is determined and necessary warnings is- sued Next in importance to accurately