The Most Effective Flood Mitigation Is A Blend of 3 Factors:Upstream Storm-water DetentionChannel Flow EnhancementLevee Height

Created by

Clark Rieke

319 521-5212

crieke@mchsi.com

These 42 mini-watersheds in the 26 sq. milesof Palo’s Dry Creek Watershed demonstrate potential locations for 42 watergates, many of which would only have to be 4’-8’ high.

This is an example of an experiment in water gate design.

This is an example of an experiment in water gate design in a 10’x8’ concrete culvert just outside of Palo, IA.

This channel between Shaver Rd. and the Cedar River can become the site for experimenting with different water gate designs.

This creek bed

has significant

temporary

storm-water

storage capacity

if water gates

are installed in

front of these

concrete

culverts under

I-35 west of

Swaledale, IA

Big Marsh in Butler County along the west fork of the Cedar River is 4400 acres. Its concrete culverts with partial water gates gives it potential as a temporary low-cost storm-water storage site.

The McCloud’s

Run and its

watershed in NE

Cedar Rapids

runs along I-380

and could be

used for

Upstream storm-

water detention.

Water gates in front of these three culverts would make McLoud’s Run basin a temporary storm-water detention site.

A water gate in front of this culvert makes the ditch alongside the railroad tracks parallel to McLoud’s Run a temporary storm-water detention site.

Waverly, IA is replacing its concrete dam with this 99% adjustable dam because this dam, with a channel flow restriction of only 1% when it is down, will reduce future flash flood crests by 2 feet and also has potential use as a valve in the river after the crest passes.

Dam in Nashua, IA, with largereservoir/lake needs to be adjustable so the reservoir can be emptied before a flood crest comes to this city as it progresses down the river basin.

This is an example of adjustable gates in a dam in downtown Cedar Falls.

If all the many dams throughout the Cedar River watershed were converted to adjustable dams, they could be used as valves to manage the height of a flood crest.

This bridge in downtown Cedar Falls demonstrates a design that does not restrict the river channel’s flow.

Both ends of the Cedar Rapids 5-in-1 Dam restrict the river’s channel.

This is a photo of the hydroelectric plant that currently blocks the Cedar River’s flow at this gate in the 5-in-1 Dam.

The hydroelectric plant at the 5-in-1 Dam restricts channel flow in one of the 10 gates.