Channels

Geomorphic changes along the Winooski River, east of Richmond

The changes of this stretch of river from 1927 (post flood) to 2004 are as follows: The southern banks become fully forested. The oxbow lake is smaller. The river channel is narrower and less tortuous. Long, well established point bars are present on the south shore. The eastern half (left half) of the river no longer has a visible yazoo stream that was hugging the south bank. The yazoo channel on the north bank next to Rt 2 is no longer visible. The western half (right side) of the river, the island has a less of a “tear drop” shape and appears to have lost its vegetation. From 2004 to 2020, the island at the western end (right side) has markedly increased in size and can be considered to be a back channel has become partially vegetated.

Peak Yearly Flow SD = 11436, Average = 22263 %SD = 51.4%

Annual Average SD = 441 Average = 1817, %SD = 24.3%

Comparison of these two sets of data indicate that the variability is greater in the Peak Yearly Flow data set. Since the peak flow in 1927 is included in the Peak Yearly data set, this very large value contributes to the increased SD of this set. The 1927 average value is not part of the Annual Average data set. Also, statistically, the Annual Average data already has averages for each year, which by itself will lower the SD. When comparing the Peak Flow and the Annual Average Flow, the peak flow is 5.8 to 24 times larger than the average annual flow. This is based on 16 pairs of Peak Flow/Annual Flow data evaluated.

date flow rank RI prob.

11/4/27 113000 1 93 0.01075269

3/19/36 45300 2 46.5 0.02150538

8/29/11 35000 3 31 0.03225806

4/19/33 34600 4 23.25 0.04301075

9/22/38 34300 5 18.6 0.05376344

3/14/77 32000 6 15.5 0.06451613

4/13/34 31600 7 13.285 0.07526882

1/10/35 30900 8 11.625 0.08602151

4/18/82 30300 9 10.3333 0.09677419

6/4/47 28900 10 9.3 0.10752688

7/1/73 28700 11 8.454 0.11827957

12/31/48 28500 12 7.75 0.12903226

4/2/76 27900 13 7.15384615 0.13978495

4/1/87 27900 14 6.6428 0.15053763

1/20/96 27800 15 6.2 0.16129032

5/5/72 27400 16 5.8125 0.17204301

12/18/00 27200 17 5.47058824 0.1827957

4/16/14 26600 18 5.16666667 0.19354839

5/16/37 26400 19 4.89473684 0.20430108

5/20/06 26200 20 4.65 0.21505376

1/9/98 25700 21 4.42857143 0.22580645

6/2/52 24900 22 4.22727273 0.23655914

3/6/79 24800 23 4.04347826 0.24731183

4/17/94 24700 24 3.875 0.25806452

11/28/59 24100 25 3.72 0.2688172

4/13/32 23600 26 3.57692308 0.27956989

12/22/18 23300 27 3.44444444 0.29032258

12/22/73 23000 28 3.32142857 0.30107527

10/24/90 23000 29 3.20689655 0.31182796

5/3/40 22800 30 3.1 0.32258065

4/4/05 22700 31 3 0.33333333

4/11/31 22600 32 2.90625 0.34408602

3/24/10 22600 33 2.81818182 0.35483871

4/16/42 22400 34 2.73529412 0.3655914

3/27/92 22300 35 2.65714286 0.37634409

4/20/75 22200 36 2.58333333 0.38709677

5/11/00 22200 37 2.51351351 0.39784946

6/30/17 22200 38 2.44736842 0.40860215

4/22/58 22100 39 2.38461538 0.41935484

11/20/03 21900 40 2.325 0.43010753

3/10/46 21600 41 2.26829268 0.44086022

10/17/77 21600 42 2.21428571 0.4516129

1/9/30 21300 43 2.1627907 0.46236559

12/14/83 21300 44 2.11363636 0.47311828

4/19/69 20900 45 2.06666667 0.48387097

5/4/71 20700 46 2.02173913 0.49462366

12/2/96 20700 47 1.9787234 0.50537634

4/25/70 20500 48 1.9375 0.51612903

5/7/89 20300 49 1.89795918 0.52688172

3/31/86 20200 50 1.86 0.53763441

4/14/02 19900 51 1.82352941 0.5483871

3/25/53 19600 52 1.78846154 0.55913978

3/22/68 19600 53 1.75471698 0.56989247

4/11/90 19600 54 1.72222222 0.58064516

2/26/16 19500 55 1.69090909 0.59139785

10/29/06 19400 56 1.66071429 0.60215054

3/17/29 19300 57 1.63157895 0.61290323

4/8/62 19200 58 1.60344828 0.62365591

4/3/59 19000 59 1.57627119 0.6344086

4/3/67 18700 60 1.55 0.64516129

7/5/13 18700 61 1.52459016 0.65591398

2/25/81 18400 62 1.5 0.66666667

12/5/50 18300 63 1.47619048 0.67741935

4/20/39 18200 64 1.453125 0.68817204

11/9/43 18000 65 1.43076923 0.69892473

3/30/03 17800 66 1.40909091 0.70967742

3/6/64 17500 67 1.3880597 0.72043011

4/25/83 17400 68 1.36764706 0.7311828

6/10/15 17100 69 1.34782609 0.74193548

4/29/88 16700 70 1.32857143 0.75268817

4/5/50 16600 71 1.30985915 0.76344086

3/22/48 16200 72 1.29166667 0.77419355

4/4/63 16100 73 1.2739726 0.78494624

9/17/99 16000 74 1.25675676 0.79569892

5/28/56 15900 75 1.24 0.80645161

1/13/18 15500 76 1.22368421 0.8172043

4/13/08 15300 77 1.20779221 0.82795699

4/15/55 15100 78 1.19230769 0.83870968

4/9/54 14600 79 1.17721519 0.84946237

4/17/93 14600 80 1.1625 0.86021505

8/6/95 14600 81 1.14814815 0.87096774

12/30/84 14000 82 1.13414634 0.88172043

3/18/45 13500 83 1.12048193 0.89247312

5/12/43 12900 84 1.10714286 0.90322581

4/23/61 12800 85 1.09411765 0.91397849

4/4/09 12800 86 1.08139535 0.92473118

4/14/41 11900 87 1.06896552 0.93548387

11/27/79 11700 88 1.05681818 0.94623656

1/23/57 11400 89 1.04494382 0.95698925

3/25/66 10300 90 1.03333333 0.96774194

3/9/12 9600 91 1.02197802 0.97849462

SD 11436.6809

average 22263

% SD 51.3707987