Constructed Wetlands Bioswales and More

Constructed Wetlands, Bioswales, and More, Oh my!: 

Constructed Wetlands, Bioswales, and More, Oh my!

Hydraulic Zones: 

Hydraulic Zones

Vegetative Zones: 

Vegetative Zones

Water Quality Considerations: 

Water Quality Considerations

Example: 

Example Pre-development: 40 acres of ag row crop Post-development 40 acres of commercial

Sizing for Water Quality: 

Sizing for Water Quality Rv = 0.05 + 0.009(0.85) = 0.05765 WQv = (1.2*0.05765*40)/12 = 0.2306 ac-ft

Storage Volume: 

Storage Volume For small drainage areas, a preliminary estimate of the storage volume required for peak flow attenuation may be obtained from a simplified design procedure that replaces the actual inflow and outflow hydrographs with the standard triangular shapes shown in Figure 2.2.4-1. The required storage volume may be estimated from the area above the outflow hydrograph and inside the inflow hydrograph, expressed as: VS = 0.5TI (Qi - QO) (2.2.6) Where: VS = storage volume estimate (ft3) Qi = peak inflow rate (cfs) QO = peak outflow rate (cfs) Ti = duration of basin inflow (s)

Storage Volume Example: 

Storage Volume Example VS(1 yr) = 0.5Ti (Qi - QO) 0.5(.4hr*3600sec/hr)(24.7cfs -6 cfs) 13,464 cu ft (.31 ac-ft)

Alternate Method: 

Alternate Method An alternative preliminary estimate of the storage volume required for a specified peak flow reduction can be obtained by the following regression equation procedure (Wycoff and Singh, 1976). (Step 1) Determine input data, including the allowable peak outflow rate, QO, the peak flow rate of the inflow hydrograph, Qi, the time base of the inflow hydrograph, tb, and the time to peak of the inflow hydrograph, tp. (Step 2) Calculate a preliminary estimate of the ratio VS/Vr using the input data from Step 1 and the following equation: (2.2.7) Where: VS = volume of storage (in) Vr = volume of runoff (in) QO = outflow peak flow (cfs) Qi = inflow peak flow (cfs) Tb = time base of the inflow hydrograph (hr) [Determined as the time from the beginning of rise to a point on the recession limb where the flow is 5% of the peak] Tp = time to peak of the inflow hydrograph (hr) (Step 3) Multiply the volume of runoff, Vr, times the ratio VS/Vr, calculated in Step 2 to obtain the estimated storage volume VS.

Water Quality Volume: 

Water Quality Volume

TR-55 (for Detention Storage): 

TR-55 (for Detention Storage)

Slide26: 

Ag Devel. Commercial Devel.

Storage Volume: 

Storage Volume

Examples: 

Examples

Robert Murase – Treatment Plant: 

Robert Murase – Treatment Plant

Murase – Willamette Treatment: 

Murase – Willamette Treatment