By John Thomas, Project Director and Fluvial Geomorphologist for the Hungry Canyons Alliance. This article is part of the Loess Country series--check back for more soon!
Erosion control or stabilization of deep gullies in the Loess Hills is challenging since filling the gully and excavating a core trench in an area of such deep ravines is often cost-prohibitive. The only practical way to stop gully erosion is with a pipe-drop structure that passes water runoff from the top to the base of the gully through a pipe.
The Hungry Canyons Alliance (HCA), in conjunction with the USDA-Natural Resource Conservation Service, is using directional drilling techniques to bore a hole at an angle through the loess soil from upstream of the headcut to the base of the gully wall. Polyethylene (PE) pipe is inserted at the base and pulled back up through the bore hole from downstream to upstream. The slurry used to drill the hole acts as a sealant between the pipe and soil making the borehole watertight as it dries. A vertical perforated PE riser is added to the angled drainage pipe to serve as an inlet. A water-retention basin is excavated upstream of the inlet, and a dam or terrace is built downstream between the inlet and the headcut of the ravine to collect water for gradual drainage through the riser and pipe. The basin allows a larger storm event to be controlled by the small drainage pipe. No filling or other work is done in the gully, dramatically reducing earthwork costs. The near-vertical gully slopes will gradually slump to a stable slope over time because collapsed debris will not be carried away by surges of runoff.
Twelve of these experimental Bored Headcut Basin (BHB) structures have been built in the Loess Hills since 2007 to control 20 – 80-ft deep gully headcuts with small drainage areas (0.5 – 37 acres). These BHB’s have averaged only about $11,000 to build, with a maximum of around $17,000. They have weathered up to 4-inch rain events without incident. Considering that a traditional pipe-drop structure may cost as much as $60,000, the BHB has proven very cost-effective. HCA continues to monitor the progress of these structures while planning future BHB projects.
If you are interested in controlling gully erosion on your property, please call your local USDA-NRCS office. Cost share for these projects have averaged 78%, so the average landowner cost for these projects has been only about $2,400. Plus, the USDA-NRCS provides survey and design assistance.
Golden Hills staff will be presenting at the Draft Meetup this Thursday evening at Barley's in Council Bluffs, discussing the many projects we do to build bikeable communities, develop regional trail systems, and promote bicycle tourism in southwest Iowa.
DRAFT is a nationwide meetup series that taps into people who love bikes, biz and beer. Our events bring communities together to celebrate the latest bike industry innovations. Speeches, announcements and conversations allow business leaders, product developers, tech innovators, advocates, artists and more to share big ideas—all while enjoying delicious craft beer.
Join us for a fast-paced event of ideas, entrepreneurs and bikes, capturing the exciting things happening in the bike industry at DRAFT: Iowa in Council Bluffs at Barley's Bar and Grill. Hosted by the Iowa Bicycle Coalition and RAGBRAI.
The event is free but registration is requested. Register here!
Barley's will be providing pizza as an appetizer for all registered attendees!
Pete Phillips - Pork Belly Ventures
Vince Asta - Ponderosa Cyclery
Julie Harris - The Nebraska Bicycling Alliance
Lance Brisbois - Golden Hills
6:00 - 6:30 pm: Beer and banter.
6:30 - 8:15 pm: Program + Speakers
8:15 - 9:00 pm: More beer and banter
We hope to see you there!
We've been working with Pottawattamie County staff to photograph the water trail using Mapillary. The imagery provides a 360° view of the West Nish Water Trail in Pottawattamie County. We have currently completed Avoca to Carson and hope to finish Carson to Macedonia in 2019. The images can be useful to paddlers and tourists, as well as to landowners and farmers along the river. It will be useful long-term to see how the river changes over time. It will also be a good way to imagine being on the river this winter when it's too cold to get out there!
A few sample images are below. Click here to see more.
By John Thomas, Project Director and Fluvial Geomorphologist for the Hungry Canyons Alliance. This is part of the Loess Country series--stay tuned for more!
Loess soil isn’t rare; what’s rare is the fact it is so thick in the Loess Hills along the Missouri River of Western Iowa. This thickness and the distinctive physical properties of loess make the Loess Hills a truly unique landform.
Loess is made up of pre-dominantly silt-sized quartz grains that are calcareous (chalky), porous, and lightweight, which cause it to be very cohesive when dry but easily eroded when wet. Vertical faces of loess in road cuts and gully walls have been known to stand for more than a hundred years, in contrast to loess slopes, which are prone to some of the highest erosion rates in the country. Old U.S. Geological Service records show a stream gage in Waubonsie Creek in the Loess Hills (Mills and Fremont Counties) recorded 2.7 pounds of sediment per gallon of water in 1947, almost three times higher than any other suspended sediment load measured on any other Iowa stream in history.
Also unique to the Loess Hills are the stair-like features found on very steep slopes called cat-steps. Gravity and water cause small rotational slips to form long, narrow benches, about a foot wide, with vertical scarps – like a flight of stairs – across the hillsides.
The deep loess soils, steep slopes, and propensity for erosion by water have created a high number of stream channels per square mile in the Loess Hills. Many of these channels are gullies that have cut deeply into the landscape, some reaching depths of more than 80 feet, and having near-vertical side walls with a semi-circular headcut, or overfall, at their upstream end. Gullies expand and erode upstream during rainfall when either surface runoff, entering the gully via the headcut, or groundwater flow, entering the gully at the base of near-vertical walls, de-stabilize the gully walls causing bank collapse. Runoff then carries away the collapsed bank debris, preparing the walls again for collapse.
While some of the larger gullies were likely present before Western Iowa was first settled in the 1850’s, many of the gullies we see today began after widespread unsustainable agricultural use on the steep, erosive uplands in the late 1800’s to mid 1900’s. The channels cut down even further after many streams in Western Iowa were straightened from 1900 to 1950. Dams, flumes, and other types of structures have been constructed throughout the Loess Hills to try to halt this channel degradation that has been so destructive to this unique landform.
We are excited to announce that we were recently awarded a $25,000 grant from the National Park Service and Outdoor Foundation for interpretation and programming along the Lewis and Clark National Historic Trail and Loess Hills National Scenic Byway through western Iowa. Golden Hills staff will work with regional National Park Service staff and byway stakeholders to inventory, update, and install interpretive panels at historic, cultural, conservation, and recreational sites in the Missouri River-Loess Hills corridor.
The project proposal includes two new interpretive signs in each of the counties that the Lewis and Clark National Historic Trail and Loess Hills National Scenic Byway have in common (Woodbury, Monona, Harrison, Pottawattamie, Mills, and Fremont). Three additional signs will also be placed in the six-county corridor, at locations yet to be determined. Most of the signs will replace existing exhibits which are several years old and weathered, with new panels containing updated content and designs to better engage visitors. In addition to the educational exhibits, Golden Hills will host three public educational events about Lewis and Clark and the Loess Hills during 2019.
The National Park Service Challenge Cost Share Program supports projects that “promote conservation and outdoor recreation, environmental stewardship, education, youth engagement” on sites administered by NPS, which includes the Lewis and Clark National Historic Trail.
Details about the project, including photos, can be found here. For more information, contact Loess Hills National Scenic Byway Coordinator Becca Castle at email@example.com or 712-482-3029.
By Bill Blackburn
(second in a series of Loess Hills articles. Stay tuned for future posts!)
Want to cut your energy bills dramatically? Build a loess home. One catch is that you have to be in the Loess Hills region which runs through Western Iowa, or in the Loess Plateau of north central China. Those are the only places where loess soil (generally a mix of wind-blown rock powder and organic humus) is found in deep deposits of 60 to 350 feet sufficient to make noteworthy hills. In both locations, the loess exhibits its unusual structural properties, which are evidenced by sheer cliffs of 50 to 100 feet or more. The material is also a good thermal insulator—cool in summer, warm in winter. So it’s no surprise that over the years, various people of limited means found it good for making homes.
Native Americans in the Glenwood, Iowa region and elsewhere in Iowa’s Loess Hills often built earth lodges, with support columns of logs covered with smaller wooden limbs or reeds and then mounded with loess soil and grass. Until a few years ago, a reconstructed lodge of this type could be seen at Glenwood Lake Park.
Early pioneers to Western Iowa often created “dugouts” burrowed into a loess hillside, with a wooden front wall with door and maybe a window, and ceiling support timbers. The excavations of several pioneer dugouts—a former blacksmith shop, a barn and a cellar--are still visible at the Green Hollow Center, my nature preserve in northern Fremont County. My father, who grew up in the loess hills near that location in the 1920s and 30s, often visited people living in such structures in the Hollow. He said they were simple dwellings, a bit claustrophobic for new guests, occasionally visited by burrowing wildlife, but pleasantly climate controlled.
In the Loess Plateau of northern China, prehistoric peoples were living in underground loess dwellings as early as the Chinese Bronze Age, the second millennium BC. It’s estimated that loess homes, called yaodongs or “cave houses” are still being used by an estimated 40 million Chinese. Three types of yaodongs can be found. Cliffside yaodongs are dug into the side of a loess cliff, creating a flat floor and arched roof. The front of the cave has one to three holes for lighting and ventilation.
Sunken yaodongs or “pit yards” are constructed by digging a large square pit that serves as a courtyard, then excavating caves into the sides of the pit. The pit is reached by an excavated ramp, or if the pit wall is not far from a cliff, by a tunnel excavated from outside the cliff through the pit wall.
Hoop yaodongs are arched structures formed with most or all of the dwelling on top of the ground. As with Native American earth lodges, loess covers the outside of the hoop yaodongs, but the Chinese version often features windows high in the arch to allow light and the warmth of the sun in winter. The inside walls of yaodongs are often plastered with white lime, and the outside may have a façade of stones or brick.
Yaodongs have had their place in important events in Chinese history. In 1556, an earthquake centered on the Loess Plateau in China’s Shaanxi province killed over 800,000 residents, many of whom died in collapsed yaodongs. The most famous yaodongs are those in Yan’an, which served as headquarters for Mao Zedong and his Communist leaders during the 1935-1948 resistance movement.
In China, loess homes continue to be popular. With the age of “eco-design” in the U.S., perhaps we’ll see their return to the Loess Hills of Western Iowa. What’s old is new.
By Bill Blackburn
(first in a series of Loess Hills articles. Stay tuned for future posts!)
Take a drive along I-29 any fine day and you will see an extremely rare site—the Loess Hills. “Loess,’ which according to Webster can be pronounced as “luss,” “Lois,“ or “less,” is a German term meaning loose or crumbly. It refers to a yellowish deposit of wind-blown rock dust found in Germany, Argentina, New Zealand, U.S., China, and many other parts of the world. However, it forms hills of significant height (60-350 feet) only in two places: in the Yellow River region in and around Shaanxi province, China, and in the mini-mountains (bluffs) in the Midwest U.S. running parallel to the Missouri River 220 miles from Mound City, MO to Westfield, IA. In Iowa, the beautiful sharp-cliffed hills pass through the western sides of Fremont, Mills, Pottawattamie, Harrison, Monroe, Woodbury, and Plymouth Counties.
Our 640,000-acre bluffs are geologically speaking relatively new, having been formed only 12,000 t0 115,000 years ago when glaciers were grinding rock into powder in the north, which was carried down the Missouri River, deposited on the bottom ground and eventually blown westerly into dunes.
But the granddaddy of loess hills is the Chinese “Loess Plateau,” which covers an area only slightly less than the entire state of Texas located several hundred miles southwest of Beijing. In China, the loess eroded from various mountain areas over millions of years, was collected in the Gobi and other deserts and from there was blown into the plateau. But the wind is still at work there, causing the plateau to gradually move to the southeast over time. As in the U.S., the Chinese loess is highly erodible, so much so that the Yellow River which passes through the plateau was named because of the vast amounts of yellow-brown loess it carries downstream.
The Loess Hills are rich aesthetically, ecologically, and historically. The U.S. Loess Hills Byway, which threads through the hills, was named one of the 10 most scenic roads in the country by nonprofit Scenic America. The state of Iowa has cited 39 rare animal and plant species in the hills. Hills animals such as the plains pocket mouse, ornate box turtle, Great Plains skink (lizard), and spadefoot toad are becoming rare and even endangered. Bald eagles and a wide range of other birds reside there or pass through annually. The bluffs contain three-fourths of Iowa’s remaining natural prairies.
The Bluffs region is one of the country’s prehistoric gems, having been traversed by humans for over 12,000 years. It is home to more than 800 archeological sites, including late settlements of Mill Creek (900 AD), where predecessors of the Mandan tribe resided, and the Glenwood site (1000 AD or so), where 80 lodge sites of Pawnee and Arikaras ancestors were discovered. The region opened the gates for pioneers moving westward from there through the Mormon, California and Oregon Trails, and later, from the eastern terminus of the transcontinental railroad.
The history of China’s Loess Plateau is even more impressive. It is the location of the 1.3 million-year-old site displaying the oldest use of fire by Homo erectus, the predecessor to modern humans. The fertility of the region around the Yellow River valley enabled it to become the cradle of Chinese civilization. It was an important trading center on the famous Silk Road. Its military importance was reflected by the famous terra cotta army of the Qin Dynasty Emperor that was buried there. The region served as the home to subsequent Chinese dynasties up to the 900s AD, when the capital was moved, eventually to Beijing.
By the time the center of Chinese culture had move out of the Loess Plateau, the area had become massively eroded from overgrazing and deforestation, with the resulting erosion filling the Yellow River with deposits of so much loess that devastating flooding of croplands became common. A huge restoration project funded largely by the World Bank set out to partially restore the plateau over an area roughly the size of New Jersey.
Whether in China or Western Iowa, the loess hills are a rare gem of past, present and future importance—aesthetically, ecologically, historically and economically. They deserve our appreciation.
The Iowa Department of Natural Resources, Golden Hills RC&D and the Loess Hills National Scenic Byway are excited to announce the Waubonsie State Park Artist in Residence awards for the Spring of 2019! Many quality applications were received from a variety of disciplines and artists in six different states. Three artists were selected to fill residencies from January through April of next year. Artists receiving the residency awards for 2019 include Thomas Harnack, Vanessa Lacy and Zack Jones. The goal of the residency program is to reach a broader audience of park-goers, thus increasing the number of visitors and ultimately educating more people about the Loess Hills ecosystem. The artists and visitors will engage with the natural resources of the park through a visual arts lens. This year’s residency program’s three artists will use their time at Waubonsie to immerse themselves in the landscape as a source of inspiration and opportunity to intensely focus on their work.
Tom Harnack was born and raised in Carroll, Iowa area and has been a dedicated artist for the past 37 years. While at Waubonsie he plans to focus his work on ceramics. Excited about the opportunity for a residency program at Waubsonsie State Park, Tom reflects on the Loess Hills, “I feel as an artist, nature is my main inspiration. When I fire my wood kiln, it takes 7 days outdoors. Whether it be the owls in the grove, or the stars before sunrise, it’s being in the natural environment that inspires my creativity.”
Vanessa Lacy grew up in rural Adrian, Missouri. She currently owns a gallery in Kansas City, Missouri, although she often escapes the city to paint in rural areas to seek nature as a source of inspiration and tranquility. Vanessa’s vision for her residency fits well with that of the program as a whole. “I believe art and the parks have always gone hand in hand. The park inspires the artist and the artist’s work inspires more visitors to visit.” Vanessa’s work will be primarily oil paint on panel, and her outreach will feature painting workshops.
Zack Jones was raised in Malvern, Iowa but began his self-taught art career while living in Tempe, Arizona. While there, he was mentored by lifetime artist Sergio Ladron De Guevara, who taught Zack traditional art and to paint with love. Since returning to his hometown in 2006, he has done just that –connecting his art to historical preservation, recreation and rural Southwest Iowa. Zack is currently doing a residency program at Whiterock Conservancy, which ties into his goal of connecting traditional landscape paintings to conservation programs. “I would like to use my paintings to highlight the unique geography while highlighting Waubonsie State Park. My artwork is at its best when there is a personal connection and common interest with others.”
Artist Sarah Berkeley is currently piloting the residency program at Waubonsie and helping to finalize program details. Sarah was born on the North Shore of Massachusetts and subsequently spent her childhood in Michigan and Colorado. She works across media questioning cultural norms such as the 9:00 to 5:00 work day, the office environment, indoor living, gender stereotypes and the voluntary sharing of personal data. She creates public interventions and durational performances which she documents using photography, video and GPS.
This first-in-the-state Artist in Residency program at one of Iowa’s State Parks is held at one of the region’s ecological and recreational treasures. Located in the Loess Hills of Southwest Iowa, the park’s 2,000 acres feature prairies, savannas, and woodlands which are home to diverse flora and fauna, not to mention breathtaking vistas. Waubonsie State Park Manager Matt Moles has been working with artist Sarah Berkeley, Golden Hills RC&D Project Coordinator Lance Brisbois and Loess Hills National Scenic Byway Coordinator Rebecca Castle to develop and launch the project. While there have been other artist residency programs offered through the National Parks System and select parks in other states, this will be the first such program in one of Iowa’s State Parks. The program is loosely modeled after similar regional programs such as the Residency Program at Kimmel Harding Nelson Center for the Arts. The artists will receive lodging in a studio cabin and a primitive studio space in the park at no cost for the duration of the residency. In return, artists will deliver at least one public program per month of their residency and donate one piece of art to the park at the conclusion of their stay.
Waubonsie State Park is only about an hour’s drive from Omaha or Lincoln, NE; two hours from Kansas City; and 2.5 hours from Des Moines. It is located near the southern end of the Loess Hills National Scenic Byway. To learn more about the Artist in Residence program and the artists, visit www.goldenhillsrcd.org/artist-in-residence.
Drone footage by Dave Poole. Visit our YouTube channel for more videos!
Golden Hills RC&D, Iowa Natural Heritage Foundation and Trees Forever are partnering to bring back the Iowa Trails Summit for 2018! Mark your calendar for Friday, October 12th! The Raccoon River Valley Trail Association will be hosting a social ride beginning at 4:30 PM Thursday evening, wrapping up with a pre-conference meet & greet!
The morning welcome session will set the stage for the day. In an interactive group discussion, we will highlight challenges, successes, and best practices. We will get to know a little about each trail group’s “story” and discover who we may learn from and who we may be able to give advice to.
Our breakout panels will feature 3 tracks - for those who Want a Trail, Have a Trail, and Water Trails. Full agenda and registration is available at