Hydrodynamic Separators

Jensen Deflective Separator

With no moving parts, the JDS is a hydrodynamic separator that is able to screen trash and debris, including floatables and both neutrally and negatively buoyant materials, from stormwater runoff without blocking the screen. Built with durable precast concrete, the JDS hydrodynamic separator also captures total suspended solids (TSS), oil, grease, and other total petroleum hydrocarbon pollutants. Captured pollutants are retained without scouring, even under high flow bypass conditions. Capable of treating flows from 0.7 to 72 cubic feet per second, the JDS Hydrodynamic Separator is certified and approved by various agencies. Contact us today to learn more about our hydrodynamic separator offerings.


Configure Product and Download Drawings

Jensen Deflective Separator Inline

Treatment Flow Rate (cfs)
Manhole Diameter (ft) Download Drawings
0.3 3 JDS36-1813 JDS36-1813
0.6 3 JDS36-1818 JDS36-1818
1.0 3 JDS36-1827 JDS36-1827
0.7 4 JDS48-2418(G)6 JDS48-2418(G)6
0.7 4 JDS48-2418 JDS48-2418
1.1 4 JDS48-2424 JDS48-2424
0.7 5 JDS60-2418 JDS60-2418
1.1 5 JDS60-2424 JDS60-2424
1.6 5 JDS60-2430 JDS60-2430
2.0 6 JDS72-3624 JDS72-3624
2.4 6 JDS72-3630 JDS72-3630
3.0 6 JDS72-3636 JDS72-3636
3.8 6 JDS72-3642 JDS72-3642
2.8 7 JDS84-4230 JDS84-4230
3.7 7 JDS84-4236 JDS84-4236
4.6 7 JDS84-4242 JDS84-4242
5.6 7 JDS84-4248 JDS84-4248
4.5 7 JDS84-4836 Contact Us JDS84-4836 Contact Us
4.5 8 JDS96-4836 JDS96-4836
6.5 8 JDS96-4848 JDS96-4848
7.5 8 JDS96-4854 JDS96-4854
8.5 8 JDS96-4860 Contact Us JDS96-4860 Contact Us
9.0 10 JDS120-6748 JDS120-6748
11.0 10 JDS120-6758 JDS120-6758
14.0 10 JDS120-6764 JDS120-6764
15.2 10 JDS120-6770 JDS120-6770
19.0 10 JDS120-6782 JDS120-6782
25.0 10 JDS120-6794 JDS120-6794
25.2 12 JDS144-8484 JDS144-8484
26.0 12 JDS144-9480 JDS144-9480
31.0 12 JDS144-9490 JDS144-9490
38.0 12 JDS144-94102 JDS144-94102
44.0 12 JDS144-94114 JDS144-94114
44.0 16 JDS192-12096 Contact Us JDS192-12096 Contact Us
53.0 16 JDS192-120108 Contact Us JDS192-120108 Contact Us
62.0 16 JDS192-120120 Contact Us JDS192-120120 Contact Us
72.0 16 JDS192-120132 Contact Us JDS192-120132 Contact Us
81.0 16 JDS192-120144 Contact Us JDS192-120144 Contact Us
102.0 16 JDS192-120168 Contact Us JDS192-120168 Contact Us

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How It Works

Jensen Deflective Separator hydrodynamic separator diagram

The JDS Hydrodynamic Separator offers a unique non-blocking and non-mechanical screening process with no moving parts and no power requirements.

  1. Stormwater enters the JDS hydrodynamic separator unit from one or more inlet pipes, a grated drop or curb inlet.
  2. Incoming water collects in the forebay of the inlet trough.
  3. Waters enter the separation and screening cylinder through the volute entrance in the diversion weir wall.
  4. Water entering the separation cylinder forms a spinning vortex, capturing all floatables and swirl concentrating suspended solids to the center of the separation chamber of the hydrodynamic separator.
  5. The vortex flow pattern produces a washing force across the screen face, preventing it from becoming blocked while allowing stormwater to pass through the screen and flow beneath the oil baffle.
  6. Oils, greases and other Total Petroleum Hydrocarbons (TPHs) are trapped within the integral oil baffle attached beneath the inlet bay of the separator.
  7. Settled and swirl concentrated suspended solids are captured in the sump which is typically cleaned out by a vactor truck.
  8. Flows larger than the JDS hydrodynamic separator unit’s design treatment flow bypass over the diversion weir. Bypass flows do not scour out previously captured pollutants.


JDS Hydrodynamic Separator Applications

  • 100% trash and debris removal
  • 50% TSS removal
  • Sediments
  • Oil, grease, and other TPH
  • Standalone treatment applications
  • Pretreatment applications
    • Detention and infiltration systems
    • Biofiltration systems
    • Media or membrane filtration systems

Agency Certifications and Approvals


Delivering value at every stage of the project lifecycle


  • Leverage proven continuous deflective treatment process for full capture of 100% of trash and debris ≥5mm.
  • Treat large flow ranges from .7 to 83 CFS with inline and offline hydrodynamic separator units.
  • Save with the most cost-effective treatment method per cfs of stormwater as compared to other structural BMPs.


  • Meet full capture requirements with a state-certified hydrodynamic separator.
  • Bid an equivalent system directly from the manufacturer to save time and money.
  • Receive a complete package quote that includes all your precast sewer and storm drainage products.


  • Install using standard methods with a JDS hydrodynamic separator unit configured inside a precast manhole set below grade.
  • Maintain your system easily and safely by opening the unit through multiple large accessways and removing trash and debris from your hydrodynamic separator with a standard vacuum truck.