Showing posts with label Shadow Lake. Show all posts
Showing posts with label Shadow Lake. Show all posts

01 July 2014

Corps to Consider Public Works Wetland Filling at Elmwood

The U.S. Army Corps of Engineers has been asked to investigate the possibility of illegal filling of wetlands at Shadow Lake, Elmwood Park.

The filling activity would involve the placement of numerous sandbags by the Omaha Public Works department within the water of the park pond and on the east pond bank of the berm.

Section 404 requires a permit to place material within waters of the United States without a permit. Placing sandbags within the pond, would involve such an activity.

Omaha Public Works apparently does not have such a permit, according to a Corps spokesman visited with later in the morning on July 1st.

Shadow Lake is considered a jurisdictional wetland because of its hydrologic connection via the brook west of Shadow Lake, which connects to Wood Creek, that flows through Elmwood Park. This eventually connects to the Missouri River, a well-known waterway where most all wetlands are jurisdictional.

There is also the likelihood that any repair work at the lower west side of the berm would require earthwork, that would more than likely involve placement of a minimal amount of dirt within the flowing brook.

The following pictures were taken late morning on July 1, at the problem site.

The western portion of the berm, showing the gully due to the erosion and the spot where the water enters the ever-flowing brook. The pipe on the left side of the picture was put in place a few years ago to provide pond drainage.

View from the brook-side to the west.

The next three images show were sandbags were placed within the waters of Shadow Lake. On the south side is where the water has already bypassed this now useless barrier, and continues to flow improperly. Due to the advanced loss of integrity in the dam berm, some of the bags have already fallen into the large hole present.

View from the south.

The green plant in the picture is duckweed (Lemna species); this is the reason why the pond is such an attractive haven for the numerous Wood Ducks and Mallards now present

View from the north.

A view of the plastic fencing and cone placed upon the berm top. The northern section of this fencing was repositioned during my first Tuesday visit, because it was mostly fallen over and was providing a barrier less than two-feet in height, rather than its entire possible barrier capacity.

View to the south.

The sewer line which traverses the berm, showing the extensive erosion to the supportive earthwork due to the adjacent stream of water.

Apparently, some time Monday, the sand bags were put in place, along with additional fencing at the problem site. These items were not present mid-morning Monday, but were there mid-morning Tuesday, July 1.

Update: According to an email received from Public Works, this site was visited by department staff on July 2nd, and that the Army Corps of Engineers was contacted that afternoon. Temporary repairs were made on July 3rd when the sewer line was stabilized, and numerous additional sandbags were placed in the pond waters, to make certain that any drainage would occur through the pipe. As of July 7th, Public Works indicated no further work will occur at Shadow Lake until a site visit occurs with Public Works and Corps staff.
Update, July 14, 2014: "It appears that the City has done what they needed to do to avoid losing an existing sanitary sewer line and the pond. At this time, the ground is super-saturated and heavy equipment cannot access the site. The City is working on a permanent solution and will contact me when they have something to propose. For now, the sandbags are preventing berm failure due to the heavy erosion on the downstream side of the berm, which is quite severe. The work they have done qualifies for a Nationwide 3c, which is a non-reporting nationwide permit." - email response received from staff of the Corps of Engineers after the site visit

26 June 2014

Dam Damage Threatens Pond at Elmwood Park

Shadow Lake at Elmwood Park is threatened by extensive erosional damage to its dam. In response, the following email with four pictures was sent to the director of Omaha Public Works, the director of Omaha Parks and Recreation, as well as the office of Omaha's mayor.

Attached are some pics showing the severely damaged condition of the dam at Shadow Lake, as noted on June 25th.

When this is repaired, how will water be kept in the pond to allow survival of the more than 20 pre-flight wood ducks now present? Draining of the pond will threaten their survival and this will be their status for another month.

This situation would not have occurred if the berm had been fixed soon after the initial report of damage as noted on May 15th...

The dam damage is significantly greater now than it was six weeks ago. It is also a greater hazard as well as a threat to the large sewer line, which can readily be seen down in the deep hole caused by the ongoing erosion.

Water improperly flowing through the earthen dam structure, rather than the installed drain.

Painted turtle enjoying the sunny setting at Shadow Lake.

Midday view of Shadow Lake on June 25th. There were more than 20 Wood Ducks present during the first, mid-morning visit.

Damage here had been originally noted on May 15th, and reported then to Public Works. There was no repair work done in response, other than placement of sandbags in an attempt to inhibit the improper drainage.

The dam which created Shadow Lake, was built to provide a route for a neighborhood sewer line.