Opinion ID: 355551
Heading Depth: 2
Heading Rank: 4

Heading: Captain Friedkin's Experiments.

Text: 109 The final proofs which defendants and the trial court relied on to establish accretion as the cause of the river's movement were Captain Friedkin's experiments and general principles of hydrology. Both Friedkin's experiments and principles of hydrology, however, provide strong evidence that avulsive change may have produced the 1879 movement. Friedkin noted that when a meander bend reaches its limiting width, 50 as it is conceded Blackbird Bend had here, it does not stop caving its banks. Instead, (t)he flow short-cuts over the convex bars of bends, chute channels form, and a new bend develops a little farther downstream. J. Friedkin, Meandering of Alluvial Rivers 14 (1945) (footnote omitted). Such chute channels 51 are avulsive since the channel moves around or over, not imperceptibly through the interjacent land. One of the defendants' witnesses, Dr. George R. Hallberg, testified that it was quite possible that chutes similar to those described by Friedkin could have formed along the eastern edge of Blackbird Bend, although he felt the area was probably submerged when this occurred. Hallberg's testimony concurred with the government's expert, Dr. Paul McQuivey, a research hydrologist, who testified that, when a river is at high flow it tends to increase its radius, that is, it tends to take a more direct course rather than a meandering one. 52 To do so, he continued, the thalweg moves to the inside of the bend, and erodes new chute channels 53 through the point bar. Eventually, the record shows, one of the chute channels becomes large enough to carry the main flow of the river, and the river abandons the old channel. 54 Cf. Veatch v. White, 23 F.2d at 70. 110 In addition to the evidence suggesting that the movement of the river in 1879 could have occurred through a series of chute channels, the evidence also supports the possibility that during this same time a cut-off could have occurred across the neck of Blackbird Bend. 55 Friedkin also described the conditions when a cut-off is likely: 111 Natural cut-offs occur when a meandering river develops and finally erodes through a narrow neck between the upper and lower arms of a bend. . . . In over 50 laboratory streams in uniform materials not a single cut-off of this type developed. This fact indicates that natural cut-offs result from local differences in the erodibility of bank materials. 112 With all bends in a meandering river migrating down the valley at the same rate, a cut-off cannot possibly develop. The upper arm of a bend never catches up with the lower arm. For a natural cut-off to develop, erosion on the downstream bank of the lower arm of a bend must be slower than along the upper arm. Generally, when a cut-off develops, erosion in the bend proper has taken place so that the flow in the lower arm of the bend has become directed up-valley . . . and a narrow neck has developed. It is, therefore, indicated that it is the local differences in erodibility of the bank materials in natural rivers which cause narrow necks to form and cut-offs to develop. Friedkin, supra at 16. 56 113 NOTE: OPINION CONTAINS TABLE OR OTHER DATA THAT IS NOT VIEWABLE 114 There exists strong corroborative proof of such occurrences from Barrett's field notes made during his 1867 survey. He wrote: 115 Until very recently, appearances indicated that this point was increasing in size from the deposits and drift of the river; but, during the present season, the river, rising to a great height, partly worked a channel across it, which may, eventually, entirely detach it from the Nebraska shore, rendering it an island in the river. 116 Tribe exhibit 26E, at 6. 117 The evidence also demonstrated that the Iowa south bank of the Blackbird Bend area was composed of erosion resistant material which would have prevented the southerly movement of the meander bend and made a cut-off possible. Cf. Friedkin, supra at 16-17. 57 In addition, the record shows that the potential for breakthroughs in the 1875 through 1879 period was enhanced by high water flows during those years. 58 118 Based on the foregoing analysis we find the factual predicate, supporting defendants' theory as the causative reason for the river's movement, is in large part conjectural and the opinions drawn therefrom must be viewed as speculative. Under the circumstances we hold that the defendants have failed to meet their burden of proof that the significant and marked changes of the Missouri River between 1875 and 1879 were the result of erosion and gradual imperceptible accretion to the Iowa bank. 119