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Explore the pipeline protection project near Denmark, Iowa, using bendway weirs and bank stabilization techniques to ensure stability in the area. Witness the pre-project conditions, installation process, and post-project effectiveness.
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SUB MAR SKUNK RIVER PIPELINE PROTECTION PROJECT NEAR DENMARK, IOWA
Looking US at Bendway Weirs and stable bank, flat slope depositional areas are an excellent indicator of stability. SUB MAR Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company
ANR Pipeline Company SUB MAR Pre-project: Looking US from the area where the pipeline was exposed by river forces Before Installation Skunk River Lee & Des Moines County, Iowa
Pre-Project: Looking US. The river was eroding the right descending bank, becoming over-widened, and eroding a top-bank farm levee. WE ARE GOING 1,000 FT OFF OF THE PIPELINE RIGHT-OF-WAY FOR A LONG-TERM SOLUTION. Before Installation Skunk River Lee & Des Moines County, Iowa
Looking US at Bendway Weirs and stable bank, flat slope depositional areas are an excellent indicator of stability. SUB MAR Flow Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company
Looking US at Bendway Weirs and stable bank, flat slope depositional areas are an excellent indicator of stability. 2 Hard Points 9 Bendway Weirs LPSTP & ACM SUB MAR Flow Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company
Looking US at Bendway Weirs and stable bank, flat slope depositional areas are an excellent indicator of stability. SUB MAR Bendway Weirs, LPSTP & ACM Flow LPSTP Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company
Looking US at Bendway Weirs and stable bank, flat slope depositional areas are an excellent indicator of stability. SUB MAR Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company
Looking DS at the ACM protection after the first flood, note erosion immediately US of the mats
Construction of Bendway Weirs, Hard Points, & LPSTP occurred in October 2001 SUB MAR
Well-graded stone, but few fines, for Skunk River project, Denmark, IA. To effectively use this stone we installed a granular filter of 1 to 3 inch stone, then installed this stone.
Key trench for Bendway Weir #9. Granular filter (1 to 3 inch stone) is installed, then overtopped with key stone.
Skunk River, Denmark, Iowa. Looking upstream. Keying into, and connecting the US Bendway Weir with the DS Articulated Concrete Mattress pipe cover protection using a section of Longitudinal Peaked Stone Toe Protection, (LPSTP, about 1.5 tons/ft.)
Looking DS after 2 yrs, at ACM protection over a formerly exposed gas pipeline Note: Pipeline was exposed at the toe of both banks, meaning the river had degraded (system-wide bed lowering) and overwidened (CEM Type III).
A system of Bendway Weirs, seen here in a physical movable-bed model, flow is left to right
UNREVETTED BEND REVETTED BEND Newly installed Bendway Weir Effects of Bendway Weir
Looking DS at flow over a series of Bendway Weirs, high water on Catt Creek & Savage Rd., NY 11/4/2004 8.0 ft/sec Thalweg 6.4 ft/sec Within the weir field 2.6 ft/sec
Looking US at Bendway Weirs and stable bank, flat slope depositional areas are an excellent indicator of stability. SUB MAR Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company
Looking US at Bendway Weir #9 on the Skunk River, 8 more Bendway Weirs up-river plus 2 Hard Points US of that, protecting 1,400 ft of bankline.
Looking US during high water, ACM mat placed to cover exposed sections of pipeline, flood has occurred since installation, weirs not in yet. Note eroded US bank.
Looking US. Sediment is being trapped by weirs. Banks are stabilized, vegetated (a good sign) with the bank building (deposition, not retreating).
Looking US at Bendway Weirs and stable bank, flat slope depositional areas are an excellent indicator of stability. SUB MAR Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company
Skunk River, looking US from pipeline crossing, two years after installation
Before Installation 1 Year After Installation SUB MAR After Installation 1 Year After Installation 2 Years After Installation Skunk River – Mats Lee & Des Moines County, Iowa Submar Drawing No. AB643 ANR Pipeline Company
Looking DS at Bendway Weirs and ACM, Skunk River, Denmark, Iowa SUB MAR Submar Mats Keys for Bendway Weirs Post-project thalweg location Bendway Weir Pre-project thalweg location ANR Pipeline Company
This last flood we had (July 2008) was pretty severe and flooded the fields on both sides of the river at the site. After the water receded a few feet and the levee was visible again, it appeared to be undamaged. Also from what I could see from the opposite side of the river (I couldn't get very close), the vegetation was undisturbed on the river side of the levee and there were no signs of erosion. The thalweg looked to be following the line of the ends of the weirs and the water close to the bank was moving very slow comparatively. And this was with a water level several feet above the tops of the weirs (about five feet from the top of the levee)........nice! Nick Beach, Construction Manager, Submar SUB MAR
Bendway weirs are a proven technology developed & used by the U. S. Army Corps of Engineers. Bendway weirs have been used in large rivers such as the Mississippi River & in small streams. Demonstration projects in small streams have found that in addition to stabilizing the outside of a bendway, weirs have provided improved fish habitat (quantity and diversity) to the stream. Bendway Weirs Redirected Flow Skunk River Lee & Des Moines County, Iowa ANR Pipeline Company Uncontrolled Flow Captured Flow Point Bar Three pipelines are covered with ACM mats in the river, seen here at low water stage. Upstream of the right-of-way bendway weirs were installed in the bend. The water is just over the top of the weirs in this photo. Flow Flow Flow Flow Flow Constructed Oct 2001