Wet Meadows: Hypotheses 1-8 ‎(2)‎

• File Number: 8461.100
• Description: Adaptive Management Workgroup
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 6/5/2006
• Author: PRRIP
• Title: Wet Meadow: Hypotheses 1-8
• Water Supply Pro - Doc Type: Report/Study

Detectability/ Time needed for
Graph Source of Level of certainty sensitivity measuring a
number Description of hypothesis information, if any (feasibility) (feasibility) response
Indlrectly narrowing hydre,oiic curn ;or (preferred width less High because based on empirical <5 years, as luny as
Mechanical than 3,000 ft) by consohdaGng channels under proDOSed flow Empincal observations on observations on CenUal Platte Easily detectable, there is at least a flow
#1 repime and balancina the sediment budqet will convert the Central Platte River. Feasibiliry: medium,
tik
lih
d t
t braiding index easily
t gfeater than 05 dunng.
anastomosed reaches of the Platte River between Overton uncer
ain
e
oo
o compu
ed that period
and Grand Island to a braided channel morphology.
successfully constrain flaw.
Reducing the number of channels in a transect to 3 or iess High because based on empirical <5 years, as long as
Mechanical under prooosed flow reoime and balanced sediment budQet Empirical obseroations on observations on Central Platte Easily detectable, there is at least a flow
#2 will convert anastomosed reaches of the Platte River the Central Platte River. Assumes certain percent braiding index easily greater than 05 during
between Overton and Grand Island to a braided channel distnbution of flow among computed that penod
morphology. channels.
None yet, need to develop
Mecharncal Increasing the Braiding Index to greater than 3 in the mam this relationship from Low because there is no basis EasUy detectable with

#3
channel wdl prpmote In the Platte River between Overton and
observations on the lower
for these numbers yet
air photos 5.10 yrs
Grand Island a total main channel wetted width exceedmg Platte River
500 to 750 ft.
Narrowing the hydrauhc corndor through consolidated flows Easily detectable for
Mechanical
to three or less channels m a transect, and a balanced
None yet Low because there is no basis individual flow by
5 10 yrs
? sediment budget, will tncrease the area of In-channel bars. for these numbers yet ground survey and aU
photos at index f1ow.
Note: #4 is revised version of hypothesis we debated adding on sand bar movement. Changed focus from bar movement to more bars
N6on of braidmg index for main channet (as used here) is: Average number of
based on limded measurements hom 1998 inha-red air photos.