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

Detectabilityl Time needed for
Graph Source of Level of certainty sensitivity measuring a
number Description of hypothesis information, if any (feasibility) (feasibility) response
Sedlment augrnentahon nr Overton of 1 u5 0i)0 tonslyr under
exisbng tlr,w iuyunc and 225,000 tonslyr uncler GC proposed Need ewsbng wnditions
ftow reflime achieves a sediment balance. Sed augm Back calculation of exposed Medium because based on flown at mdex flow.
Sediment combined with mech actions (channel consolidation, bars in remaining braided empincal observations on Easily detectable with air 5• 10 years
#? widening) and proposed Flow regime, will increase and ??ons downstream
of centralllower Platte River photos if (lown at index
mamtain exposed bar area greater than X acres beriveen Ov Keamey tlow.
8 Gr Isld at an index flow of 1,200 cfs (at Overton).
Sediment augmentation of 225,000 tons/year near Overton High because this estimate is

will achieve a sediment balance under proposed flows, and
based on a combination of Difficult to estimate

Sediment
when implemented with the proposed flow regime and
Sed Veg, topographic
sediment transport capaclty sediment Contribution

#2
mechanical actions (Channel cAnsolidation & wldening) will
differencing
esUmates as well as estimates Nom tnbs, Sediment 5-10 years

pror,iote braided channel morphology between Overton and
of tributary sediment budget is diffiCUlt to

Grand Island.
contribution measure
e imen augmen ion o 225.000 on year ne r ve on
Nnll acfifeve a sediment balance under proposed flows, and
when implemented with the proposed flow regime and Braiding index easily

Sediment
mechanical actions (channel consolidation 8 widening) will
Empirical observations on Medium because based on
computed once it is

#3
convert anastomased reaches to braided, and help maintain
the Central Platte empirical observaGOns
on
defined tor the central
years
?10
braided roaches of the Platte River, beNveen Overton and central/lower Platte River platte Rvier
Grand Island with an average braiding index in the main
Increasing the average braiding index to greater than 3 for

the mam channel in the sediment deficient reach near None yet, need to develop
Sediment
Overton will increase and maintain expased bar area greater this relationship from Low because there is no basis Easdy detectable wrth air
? r, y,•; n,
#4 than X acres in the reach between Overton and Grand Island observa6ons downstream of for these numbers yet photos
at an index Row of 1,200 cfs (at Overton). Keamey