Jon E. Rasmussen, P.E., CPESC, LEED AP BD+C

What is the most typical way to attenuate storm water runoff today?

Static Control Structure

Description/Capabilities:• Fixed opening;• Attenuate the peak flow rate;• Discharge is proportional to depth of water;• Attenuate single or multiple design storms;• Discharge by reservoir routing equations.

Limitations:• Do not control the volume of runoff;• Naturally delay basin peak time;• Discharge higher flow rates during the trailing end

of the storm;• Can contribute to downstream erosion;

Static Control Structure

So what is Flood-Con?1. Patented automated flood control

device;2. Composed of a rain gauge, depth

sensor and uses program logic to emulate (re-create) pre-developed storm water runoff from a site development.

Description/Capabilities:• Provides downstream channel protection by replicating the

natural pre-developed flow rate;• Attenuates actual storm events in real time for any rain event; • Prevents downstream flooding resulting from delayed peak flow

time;• Replicates pre-developed developed peak flow time(s);• Variable orifice openings;• Follows the pre-developed hydrograph;• Discharge is independent of depth of water;

FLOOD-CON

Pre-Development DataDrainage area: 16.1 acresCN = 59Tc = 22.8 min.

Post Development DataDrainage area: 17.5 acresCN = 86Tc = 10.8 min.

24hr DesignStorms1yr, 2yr, 5yr,10yr, 25yr, 100yr

Static Structure Outlets: 6”, 18”, 18”, 20” dia.

Flood-Con Gates:18 Gates- 2” incr. (0”-36” dia.)

5 TIMES MORE DISCHARGE

4 TIMES MORE DISCHARGE

2.5 TIMES MORE DISCHARGE

2.5 TIMES MORE DISCHARGE

2.5 TIMES MORE DISCHARGE

2.5 TIMES MORE DISCHARGE

POND

DEVICE

GATES OPENAND CLOSE

TEST COMPARISION

Pre-development data

Drainage Area: 200 Sq. ft.CN = 73Tc = 5 minutes

Post development dataDrainage Area: 200 Sq. ft.CN = 85Tc = 5 minutes

Design Storm2yr-1hr

Depth (in)1.8

Static Structure Outlet:5/16” Circular Orifice

Flood-Con Gates:4 Gates- 1/8”, 3/16”, 1/4”, 5/16”

Pre peak flowrate: 96.25 gphPost peak flowrate: 300 gph(simulated with 500 gph pump)

VALVE

75 GAL TANK

POOL

1/8”

5/16”

STATIC STRUCTURE VS FLOOD-CON- LIMITED TO DESIGN STORMS;- CONTRIBUTE TO EROSION;- DISCHARGE IS BASED ON DEPTH;- LIMITED ATTENUATION OF REAL

STORMS;- PEAK TIME DELAY;- NO RECOGNIZED WATER

QUALITY

- CONTROLS ALL STORMS- BEGINNING TO END;

- NATURAL RUNOFF;- DISCHARGE IS INDEPENDENT OF

POND DEPTH;- ATTENUATES ALL STORMS;- NO PEAK TIME DELAY;- EXTENDED DETENTION AND

RUNOFF REDUCTION FOR IMPROVED WATER QUALITY;

- Wi-Fi COMMUNICATION;- 24/7 CLOUD BASED MONITORING;- WEB APP TO VIEW REAL TIME

PERFORMANCE