Timber on the Levees
Guttenberg, Iowa — Before locks and dams were built on the Upper Mississippi River, riverbanks in many rivertowns were lined with parks. Tall trees provided shade and ambience.
All that changed when the Army Corps of Engineers determined that the only flood-safe levee is a treeless levee. Only communities with treeless levees and floodwalls are eligible for post-flood assistance from the Corps.
Apparently the people in Guttenberg didn’t know the rule, because in the last ten years they’ve planted 72 trees along three-quarters of a mile of floodwall in Ingleside Park. The tree-planting has been a project of the town’s second graders. Now the town will have to remove them, obtain a variance from the Corps or turn down post-flood assistance.
City council member John Hess estimated removal will cost $600 per tree, or $46,800.
So far the Corps has refused the variance request and citizen petitions. Tree roots fracture and break up the compacted soil in a levee, leaving it more permeable and vulnerable to flooding.
Guttenberg isn’t the only town with trees in the levee area, according to Rick Hauck, the Corps’ St. Paul District levee safety program manager. The Corps stepped up its levee inspections following Hurricane Katrina. More than half the levee systems in the St. Paul District, which extends form St. Paul to Guttenberg, have trees in the vegetation-free zone. Dubuque will also have to remove all vegetation within 15 feet of the toe of the levee along 6.2 miles of riverfront this summer. (Dubuque Telegraph-Herald 2-6-11)
Hastings, Minn. — The story continues in Hastings, where a hydropower developer yanked its turbine a year ago because of high water.
The turbine, which was suspended from a barge, will go back in the water just below Lock and Dam 2, at Hastings, as early as March, according to Hydro Green Energy LLC of Houston, Texas.
In the meantime, the existing hydropower plant at Lock and Dam 2 underwent maintenance that required shutting off the flow of water to the conventional hydro unit. That meant the newfangled barge-hung turbine would get virtually no current.
“Conditions to return the unit in the summer were not ideal,” said Mark Stover, spokesman for Texas-based Hydro Green, “so we kept it in storage,” in St. Paul.
Hydro Green’s modest 35-kilowatt installation at Hastings is an experiment. At least one other firm plans to harvest energy with turbines in river currents, but Hydro Green says the Hastings project remains the only one ready to feed the grid.
Hydropower has been used to generate electricity at dams for decades, but Hydro Green uses a new technique that doesn’t require a dam. Current turns the 12-foot-diameter blades in the same way that wind drives a wind mill. The firm’s turbine, which Hydro Green calls the first U.S. commercial hydrokinetic project, began operating at Hastings in 2009. Though it requires no dam, Hydro Green chose to piggyback on Hastings’ existing hydro plant license to streamline the regulatory process. Even then, the process took three years.
Traditional dam-based hydropower requires even more years of planning and regulatory approval.
Hydro Green and at least one other developer are testing dozens of Mississippi River sites and may eventually install hundreds of generators. Other hydrokinetic turbines may eventually be mounted on the river bed.
Hydrokinetic technology may someday generate sustainable electricity close to existing power lines along the Mississippi.
Investors evidently still like Hydro Green’s prospects. The firm, founded in 2002, still has no other blades in the water but has raised $4 million and plans to close a new round of investor financing this spring. Meanwhile, it seeks licenses for “several new, low-head hydro projects” at existing dams “with a modified version of the Hastings turbine,” said spokesman Stover. Hydro Green hopes to install projects ranging from five megawatts to 15 megawatts in late 2012.
One of the touted benefit of its generators is the relative ease of removing a barge-hung unit. So, in a way, the experiment is a success, so far.
Zoo to Playscape
La Crosse, Wis. — Financial constraints have forced the Myrick Hixon EcoPark to alter its ambitious plans for creating exhibits of living indigenous animals. The new proposal calls for four “playscapes” designed to teach kids about water, forest, prairie and farm ecosystems while they play.
The new plan would cost about half as much as the $12 million to $14 million for the previous plan, which called for a zoo featuring native animals, such as bears, otters and a bobcat, in natural settings.
After the EcoPark Board raised $2 million for the new nature center building, it found funding drying up as cost estimates grew.
The Myrick Park Zoo opened at the site in 1929 and closed in 2007. People who loved the monkey exhibit were partly mollified by the promise of otters. New plans call for a frog pond, bird feeders, a butterfly garden and cut-away ant hill and beehive.
Jeff Su, EcoPark director, noted that the new plan better fits the site, which is about a fifth the size of the Midwest’s smallest zoo. It also better fits the EcoPark’s $300,000 budget. Keeping animals is extremely expensive, Su said. (La Crosse Tribune, 1-19-11)
It looks more likely that some silver and bighead carp have moved past the barrier that is supposed to keep them out of the Great Lakes.
Conservation Letters, A Journal of the Society of Conservation Biology published the first peer-reviewed paper on the use of environmental DNA (eDNA) to detect the presence of Asian carp in the Chicago canal system. The paper “’Sight-unseen’ detection of rare aquatic species using environmental DNA” was published online January 4, 2011. Three of the four authors are from the University of Notre Dame and the fourth is with The Nature Conservancy.
The study compared test results from several controls, including other waterways without Asian carp. The results bolster the likelihood that eDNA testing is an effective method for detecting the presence of unseen fish species in a body of water. Testing has found eDNA of both silver and bighead carp on the Great Lakes side of the electric barrier between the Illinois River and the Great Lakes.
The paper acknowledges that there may not be enough of either carp on the Great Lakes side to establish a viable population.
At the end of 2010, the Obama Administration announced it is adding 13 new initiatives to battle the spread of Asian carp in 2011, including expanded eDNA testing. This includes expanding the U.S. Fish and Wildlife Service laboratory in La Crosse, Wis., to increase its ability to perform eDNA tests in all of the Great Lakes.
Despite pressure from Great Lakes states and provinces, the Obama Administration has refused to close the artificial waterways connecting the Great Lakes to the Illinois and Mississippi rivers.
Another project aims to reduce the algae that the Asian carp eat in the Illinois River by reducing phosphorus and nitrogen discharges from wastewater treatment plants.