Assessing the Performance of a Sloped-Block Ice-Control Structure
Publication: Journal of Cold Regions Engineering
Volume 21, Issue 1
Abstract
Hardwick, Vt., having experienced 10 ice-jam floods in , has not experienced one since construction of a sloped-block ice-control structure (ICS) in 1994. This innovative structure consists of four sloped granite blocks spaced across the Lamoille River upstream of the village and adjacent to a treed floodplain. It arrests ice runs, forms partially grounded jams, and retains these jams for hours to days. The measured ice-hydraulic characteristics of the breakup runs and resulting ice jams (e.g., wave celerities and amplitudes, porous-flow seepage coefficients) are similar to characteristics obtained from the 1:10-scale model tests used to develop the structure. Seepage coefficients, and hence jam porosities, generally increase with increasing discharge, and only two breakup events have caused floodplain flow. Water temperatures of measured during a breakup event confirm that ice melting can account for the rate of porosity increase. Field and model data indicate that ice-jam holding time and jam-release discharge increase with increasing ice-piece thickness to a threshold of 6–7% of ICS gap width, beyond which no releases occur. Consistency between prototype and model ice-hydraulic characteristics and ice-holding capacity reinforce the conclusion that the sloped-block ICS can reliably retain ice jams during breakup events that pose the greatest flood threat: thick, strong ice, and large breakup waves. This ice-retention behavior can account for the observed reduction in ice-jam flooding in Hardwick during the past 11 seasons.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Nearly everyone in CRREL’s Ice Engineering Group has contributed over the years to the design, construction, and monitoring of the sloped-block ice-control structure: J.C. Tantinclaux, Kate White, Steve Daly, Andy Tuthill, Ed Foltyn, John Gagnon, Charlie Clark, Bob Haehnel, Jesse Stanley, and Carrie Vuyovich. The writers sincerely thank them for their efforts and continued interest in the project. The Town of Hardwick and the Federal Emergency Management Agency split the construction cost of the prototype ICS, and Hardwick continues to maintain it. We also gratefully acknowledge the support of the U.S. Army Corps of Engineers civil works research program for initial development and continued monitoring of the ICS.
References
Bear, J. (1972). Dynamics of fluids in porous media, Dover, New York.
Beltaos, S. (1993). “Flow through breakup jams.” Proc., Canadian Hydrotechnical Conf., Fredericton, N.B., Canada, 643–652.
Beltaos, S. (1999). “Flow through the voids of breakup ice jams.” Can. J. Civ. Eng., 26, 177–185.
Beltaos, S. (2005). “Field measurements and analysis of waves generated by ice-jam releases.” Proc., 13th Workshop on the Hydraulics of Ice Covered Rivers, Hanover, N.H., 227–249.
Buttle, J. M. (1994). “Isotope hydrograph separations and rapid delivery of pre-event water from drainage basins.” Prog. Phys. Geogr., 18(1), 16–41.
Calkins, D. J. (1985). “Ice jam prevention measures, Lamoille River at Hardwick, Vermont, USA.” Proc., 2nd Int. Conf. on the Hydraulics of Floods and Flood Control, Cambridge, U.K., Paper C3, 149–168.
Federal Emergency Management Agency (FEMA). (1987). “Flood insurance study, Town and Village of Hardwick, Vermont, Caledonia County.” FEMA Community No. 500027, FEMA, Washington, D.C.
Hopkins, M. A., Daly, S. F., and Lever, J. H. (1996). “Three-dimensional simulation of river ice jams.” Cold Regions Engineering—Proc., 8th Int. Conf. on Cold Regions Engineering, R. F. Carlson, ed., Fairbanks, Alaska, 582–593.
Lever, J. H., and Daly, S. F. (2003). “Upstream effects of Cazenovia Creek ice-control structure.” J. Cold Reg. Eng., 17(1), 3–17.
Lever, J. H., Gooch, G., Tuthill, A., and Clark, C. (1997). “Low-cost ice-control structure.” J. Cold Reg. Eng., 11(3), 198–220.
Liu, L., and Shen, H. T. (2005). “Numerical modeling of 2003 Grasse River ice jam and scenario analysis.” Proc., 13th Workshop of the Hydraulics of Ice Covered Rivers (CD-ROM), Hanover, N.H.
Nislow, K. H., and Lever, J. H. (1998). “Assessing the ecological impact of an ice control structure.” Ice in Surface Waters—Proc., of 14th Int. Sym. on Ice, H. T. Shen, ed., Potsdam, N.Y., 787–792.
Prowse, T. D. (1990). “Heat and mass balance of an ablating ice jam.” Can. J. Civ. Eng., 17(4), 629–635.
U.S. Army Corps of Engineers (USACE). (1998). HEC-RAS river analysis system, user’s manual, version 2.2, Hydrologic Engineering Center, Davis, Calif.
Wong, J., Beltaos, S., and Krishnappan, B. G. (1985). “Seepage flow through simulated grounded ice jam.” Can. J. Civ. Eng., 12(4), 926–929.
Information & Authors
Information
Published In
Journal of Cold Regions Engineering
Volume 21 • Issue 1 • March 2007
Pages: 19 - 39
Copyright
© 2007 ASCE.
History
Received: Jan 11, 2006
Accepted: Mar 20, 2006
Published online: Mar 1, 2007
Published in print: Mar 2007
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.