Recent Research Projects

Physical Model Study of the Bond Falls Emergency Spillway
The Bond Falls Earthen Dam located in the Upper Peninsula is approximately 50 ft. high with a crest length of 280 ft. The existing spillway is rated for 4600 cfs but with minor gate actuator modifications could pass 6000 cfs. This however; is insufficient to pass the probable maximum flood estimated to be 13,500 cfs. The purpose of this model study was to investigate two proposed spillway designs. Design constraints consisted of a low automotive bridge just down stream of the gates and a shallow spillway channel that cannot contain the outflow and thus spills out of the system jeopardizing the integrity of the earthen dam. Additionally minimum bridge cord elevations were provided for the eventual construction of a new bridge. Design one specified a smaller two gate system just adjacent to the existing structure but did not modify the in place spillway. The entrance condition from the new system to the existing channel caused overtopping that would most definitely cause erosion of the toe of the embankment thus jeopardizing reservoir integrity. Design two was a larger double gate system centered in place of the existing. This was the most desirable design and with some minor modifications was able to pass PMF.

Hydraulic Model Study of the Folsom Dam Auxiliary Spillway
To assess the performance of the proposed stilling basin of the new auxiliary spillway system in dissipating 312,500 cfs under the PMF, a 1:26 model of the control structure, the chute, the stepped spillway and stilling basin was constructed at SAFL.  The model was about 150 ft long and 9 ft wide.  The maximum discharge through the model was 91 cfs, corresponding to 312,000 cfs at the prototype scale.  The Sacramento District of the US Army Corps of Engineers was primary client for the project. Modifications were proposed and tested in the laboratory with the final design safely passing the PMF.

Stilling Basin Hydraulic Model Study
To assess the performance of a stilling basin under the probable maximum flood, standard probable flood, and the reservoir draw down discharge conditions and different tailwater levels, and to determine the velocity magnitudes downstream of the stilling basin to design the necessary protection measures, a hydraulic model study was conducted at the St. Anthony Falls Laboratory. A series of three tests were conducted in this model study, with results showing the best stilling basin performance tailwater levels. These studies were commissioned by MWH Americas Inc.

San Antonio River Navigation Lock Chamber
The objectives of this study are to construct the hydraulic model of the San Antonio River Navigation Lock Chamber and to use it as a design aid to reduce the hazardous impacts of filling and emptying of the lock chamber on the vessels. The main goal of this model study is to evaluate the chamber performance during filling and emptying of the chamber. The chamber performance indicators are surface currents and turbulence, and hawser forces on mooring lines. This project has been commissioned by HDR Inc.

Homme Dam Safety Improvements Park River, N. Dakota
A physical model was constructed of the Homme Dam spillway and outlet channel in Park River, North Dakota to verify the adequacy and test the optimality of the proposed outlet-channel riprap protection, and to determine the spillway rating curve. The study showed that the proposed outlet channel protection withstood the probable maximum flood (PMF) without damage to the spillway structure and with only minor damage to the outlet protection. An even more economical design of the outlet channel protection was proposed and tested, leading to cost saving of about $200,000.

Siphon Intake to the Brasfield Dam Hydroelectric Facility
This study addressed the combined concerns of discharge water quality and intake vortex suppression in a three-megawatt hydroelectric plant with 41 feet of head and siphon intake for 1,000 cfs. Our studies indicated that for water quality protection, the withdrawal should be as shallow as possible. This necessitated an intake model test for design vortex suppression devices. The suppression device considered was an underwater grid which was proven to eliminate vortices even with just three feet submergence.

UNOCAL Pump Sump Hydraulic Model
Based on the engineer's preliminary design, SAFL constructed and tested a recirculating model of the proposed intake sump. The sump included two vertical turbine mixed-flow wet-pit pumps, withdrawing water followed by two large diameter inlet pipes. Our testing and recommendations led to design changes to improve the velocity distribution of the proposed intake screens and pump intakes themselves. Photos show the recirculating flow set-up, intake bellmouth and sump structure.

Busse Woods Reservoir and Drop Structure
The Busse Woods Reservoir and Drop Structure are located in Cook County near Chicago Illinois. The Illinois Department of Transportation (IDOT) planned to modify the conventional Soil Conservation Service drop structure and stilling basin to increase flood storage and decrease downstream flooding. In order to maintain both low flow and retain higher flows, IDOT proposed that a 2.3 ft high fixed gate be placed at 1.2 feet above the existing crest. SAFL was contracted to build and test a physical model of the altered spillway. The model was used to determine the beam elevation to achieve the design reservoir flood stage. A movable bed was included to evaluate the need for riprap to protect the stilling basin end sill from higher exit velocities.

Starved Rock Lock and Dam, Navigation and Sediment Study
SAFL assisted the City of Peru, Illinois, with its investigation of construction and operation of a new hydroelectric facility at the Starved Rock Lock and Dam on the Illinois River. The City's objective was to sell power to the local electric utility and use profits as a continuous revenue stream for the City. As a result of the FERC licensing procedure, the City was required to address US Army Corps of Engineers concerns regarding navigation and sedimentation which might result from changes in flow. SAFL built a physical model in its 155 ft by 28 ft river model basin for this study. For the navigation part, SAFL engineers cooperated with Waterways Experiment Station engineers who navigated a radio controlled tow boat and barge through the locks, with and without the hydro plant and for low through flood flow conditions. The study showed that changes in currents were small and caused only minor effects on navigation at the downstream lock entrance.