Lake Superior Zoo – Duluth, MN

Lake Superior Zoo/Kingsbury Creek: Audit & Best Management Practices

October 10, 2008

This project was funded in part by the Coastal Zone Management Act, by NOAA’s Office of Ocean and Coastal Resource Management, in cooperation with Minnesota’s Lake Superior Coastal

Program.

Contents

Background………………………………………………………………………………………..3

Spring Audit……………………………………………………………………………………….7

Summer Audit……………………………………………………………………………………12

Winter Audit………...…………………………………………………………………………….4

Fall Audit………………………………………………………………………………………...19

Appendix A: Basic Best Management Practices………………………………………………...25

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Background

The South St. Louis Soil and Water Conservation District (SWCD) conducted four seasonal audits of zoo grounds to identify areas and practices where Best Management Practices (BMPs) could be implemented to help improve and protect the water quality of Kingsbury Creek, a designated trout stream, that begins northwest of Duluth, and runs through the zoo on its way the St. Louis Bay and eventually into Lake Superior. The creek is currently being impacted by sediment discharges from areas that become eroded from visitors or animals, and from animal waste, specifically waste from the large Canada geese population that often takes up residence on zoo grounds.

It is expected that this audit will lead to: 1.) recommendations for BMPs from the SWCD to zoo staff that will help improve and protect the water quality of Kingsbury Creek; 2.) purchase of equipment to implement recommended BMPs; 3.) a training session conducted by SWCD for zoo staff on how to use recommended equipment; 4.) a printed manual identifying the recommended BMPs and how to use the equipment purchased to implement BMPs. Ultimately, it is hoped that the BMPs implemented by the zoo will lead to improved water quality in the creek. This will be measured by the zoo through an existing partnership it has with Proctor High School, which tests the water chemistry of Kingsbury Creek as part of its science curriculum.

Contacts at the South St. Louis SWCD for this project as of October 10th, 2008: Kate Kubiak, Conservation Specialist R.C. Boheim, District Manager Keith Anderson, CCLNS Conservation Engineer

Contact at the Lake Superior Zoo for this project as of October 10th, 2008: Leslie Larson, Education Coordinator

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Winter Audit: January 24, 2007

This picture was taken outside of the Griggs Learning Center.Energy dissipation is needed at the bottom of this downspout to prevent further erosion. One solution may be to install a rain barrel to catch the water. The water could be used for gardens or for the animals. An extendable gutter may also help to get the water away from the

building.

Both of these pictures were taken to the west of the Primate Conservation Center between the service road and Grand Avenue. A no mow zone is suggested in this area to slow down the water coming off of the parking lot on its way to

Kingsbury Creek.

This picture was taken standing by the Ravens looking up towards the Children’s Zoo. This area of lawn is popular for

geese to hang out on and at times gets overloaded by waste washing into the creek. This may be a good location to plant some native plants or leave a small no mow zone to slow down and further treat the waste before it reaches the creek.

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This picture was taken looking at the Ravens, right next to Kingsbury Creek. This seems to be an area with a natural depression and ends up collecting a lot of water. zoo staff informed us that they have built a small rain garden in this location by planting native plants. For some reason the plants did not live. This would be a good location to build a rain garden with the correct soils and plants.

This is a picture of the hill below the Willard Munger Animal Care Center. If this area is not used for anything it could be a possible no now zone. This would reduce the mowing cost and filter and treat stormwater before it reaches Kingsbury Creek.

These two pictures were taken below the Asian Caravan on the way to Polar Shores. Water from the Asian Caravan is running over the walk way on its way to Kingsbury Creek. Large amounts of salt and sand have to be put on the walk way in the winter months when the water freezes. Either the main cause of the water flow needs to be fixed or the water needs to be diverted under the walkway by installing a culvert. If de-icers must be used, using environmentally friendly de-icers with less salt content would protect the creek from sodium chloride pollution (caused by deicers running off the pathways during spring runoff). The Asian Caravan area itself is showing evidence of erosion from concentrated flow. Care should be taken to maintain a good cover of vegetation in the area. The soil could possibly be amended (incorporate compost or other enhanced growing medium) to improve growing conditions. Additionally, one or more diversion terraces with tile inlets could be constructed that would help to safely transport runoff down the hill.

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Runoff from the Pavilion roof is causing erosion along the building. A better gutter system is needed. There are several gutter options available (such as extendable gutters) that could help get the water away from the building. This would be another good area to install a rain barrel to catch the rain water for use around the zoo.

This picture was taken at the bottom of the Northern Territory. This whole area is severely eroding as a result of large, hoofed animals over stressing the area. There is talk about moving wolves into the area which will help out any future erosion problems, but something still needs to be done with the current situation.

Winter audit findings – One of the main themes we found while walking around the zoo is that there are a lot of open areas that could be designated as no mow zones and left to grow native or natural vegetation. These areas would help to treat and infiltrate the stormwater from the zoo grounds. By reducing the mowing area for the zoo the cost of contractual mowing may also be reduced.

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Spring Audit: May 17, 2007

This picture was taken next to the Bald Eagle exhibit. The rock channels to the right of the picture are a useful BMP and could be mimicked elsewhere on the grounds.

This photo was taken near the waterfall. It appears that this erosion is caused by visitors walking in this area. The nearness and downward slope of this area necessitates a restriction on human presence here. Barriers could be boulder walls or other aesthetically pleasing structures depending on the zoo’s capacity and preference. Signs indicating restricted access would also provide a valuable education opportunity (e.g. “help us restore this area by staying on the trails”).

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This photo shows evidence of sediment entering Kingsbury creek. It was taken on across the sidewalk from the Northern Territory exhibit. The source of the sediment needs to be identified and fixed. SWCD staff can assist the zoo with this.

This photo shows erosion in the Northern Territory Exhibit. It appeared that animals were no longer inhabiting this exhibit during the Spring audit. There was mention in the Winter audit of moving the wolves into this exhibit. Any unhooved animal would help prevent erosion here. Erosion such as this should be restored before the area becomes used again. Re-vegetation may be difficult since there is a lot of shade here. The soil may also be a bit unstable if there is a sewer pipe lying beneath the area as suggested in the photo.

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Keeping visitors on the trail will help here. Planting native grasses/refraining from mowing would also stabilize the area.

The rock channels are not performing as well as they should here – the eroded areas next to the channel show that water is circumventing the channel. The channel needs to be widened and possibly deepened to accommodate the quantity of water the channel is serving.

The collapsed retaining wall needs to be fixed immediately. The rest of the wall also appears vulnerable. Gabion Baskets or a terraced bank may serve the bank better – the best approach would need to be determined by examining the stream’s flow characteristics here. The SWCD has staff trained in stream assessment and can help the zoo with this task.

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The cause of erosion is unidentified here. Animals could be blocked from the area so that the cause be identified and vegetation could grow back.

Spring Audit Findings - One of the main themes we found while walking around the zoo during the spring audit is that much of the open areas of the zoo are unrestricted to visitors. This adds to the park-like nature of the zoo but leaves open areas susceptible to erosion. Not mowing open areas could help reduce this activity, however, lack of mowing may compromise the aesthetics of the grounds. If mowing must be done, visitors should be encouraged to stay on the trails, especially near vulnerable areas such as the waterfall. Leaving areas unmowed, or, even better, planting native grasses and forbs to increase the aesthetic value of the open areas along with stabilizing the soil and providing filtering medium for stormwater, could help reduce erosion in open areas.

Erosion within the exhibits may prove to be easier as animals may be more responsive to blockades than the zoo’s many (and excited) visitors. While reducing space in the exhibits it not ideal in the short term, taking time to restrict problem areas and test techniques that will withstand the activity of animals may satisfy some of the zoo’s long-term goals. SWCD staff can recommend techniques to test in problem areas.

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Summer Audit: July 30, 2007

The riprap on this slope is creeping onto the pathway. The pathway is adjacent to the lion’s exhibit, east of Kingsbury Creek. The riprap covers the bottom half of the slope; the upper half is vegetated. There is fabric beneath the rip rap. Zoo staff noted that the riprap used to be about 1 ft. farther back. Because the riprap is encroaching so far onto the pathway, it is becoming more and more difficult for zoo service vehicles to get through. Kate Kubiak discussed the issue with Keith Anderson, engineer for the CCLNS Joint Powers Board #3, Keith noted several things – first, water flowing through this slope could be causing it to creep forward. An engineer would need to bore

into the hill to see where the water is flowing and to identify what steps to take to keep the

riprap from moving. Keith also noted that replacing the small riprap with larger riprap

may provide more resistance to the slope’s movement. Sediment is also being exposed as

a result of this process.

This is a view from the top of the slope. It is mostly vegetated. The fence is there to protect the public from falling down the hill.

The west side of the zoo’s parking lot is also located at the top of the slope.

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This is a photo of the pool below a waterfall on the creek (north side of the zoo). Due to low flow, this pool has been filling in with sediment over the past few years. An island is present (red circle) most of the time now, and has vegetation growing on it. Zoo staff indicated that when the flow was high, the waterfall and pool had high aesthetic value, so the pond slopes were kept mowed. Since the original aesthetic value to the zoo has diminished, this area would be a good candidate for becoming a “no-mow” zone.

This is a photo of the same area as above looking south. Note the diminshed aesthetic value (you can not see the creek).

This area that winds south around pool – zoo staff indictaed that this area could be made a “no-mow zoen” without impacting the aesthetics of the grounds in this area.

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This photo was taken near the bridge on the west side of the park – there is no rock wall here to protect the creek from run-off as in the photo below. Making this area a “no-mow” zone would provide a good buffer for the creek.

The rock wall seen in this photo protects the creek from run-off. The green box in the photo is the City of Duluth’s water quality monitoring station.

Path running along the Northern Territory. Note the sediment in the pathway. Problems in this area have been noted in during previous seasonal audits. A ditch once existed along the fence – it has filled in with sediment. Something needs to be done here to keep sediment from the deer yard from running across the path into the creek.

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Sediment deposits around a drain near the Northern Territory. This sediment should be swept up and discarded out of the path of stormwater so that it does not end up in the creek.

This small area is not mowed and, surprisingly, is not over-run with invasive tansy like other parts of the grounds. Wild carrot/Queen Anne’s Lace (a native MN wildflower) is present in this area instead. Zoo staff noted an interest in removing the rocks from this area and continuing to leave it unmowed. There is already a sign explaining why it is unmowed (inside pink circle). This type of sign is perfect for educating the public about what the zoo is doing to protect the creek.

Zoo staff indicated that this area is frequently flooded. SWCD staff recommend installing some type of buffer between the pathway and the creek to protect the creek from runoff. Because the lawn area on this side of the bridge is so narrow, it is recommended that runoff be collected and diverted to the area shown in the next photo where there is a larger area to work with.

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Zoo staff attempted to create a rain garden in this area – unfortunately it did not take (the iris did survive). Zoo staff could make another attempt at a rain garden in this area with help from SWCD staff. The rain garden could be sized to take runoff from the area shown above as well. A curb could be installed along the pathway to direct water to the rain garden, and a curb cut could be created to allow the water to empty into the rain garden.

This road (east side of the park off of 72nd

Ave. W.) is used for zoo service vehicles. Erosion is quite evident. It is unclear if this erosion is directly impacting the creek.

Zoo staff would like to keep this area mowed to ensure visibility onto zoo grounds from Grand Ave.

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This photo shows where sump pump discharge from the animal care bldg. in the background is traveling all the way down this hill and forming a small gully at the base. This should be of low priority for the zoo as it is not causing much damage and is not impacting the creek.

The sidewalks surrounding Raven Island will eventually crumble into the creek. This is not causing an immediate impact to the creek but is something the zoo will have to deal with eventually.

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Summer audit findings – The summer audit was very informative - it began with a meeting between Kate (SWCD), Leslie (education coord.), Paul (interim dir./zookeeper) and Katherine (part-time keeper; also a master gardener). Katherine walked around the zoo grounds with Kate and talked about the biggest “problem areas” for the zoo and the efforts that zoo staff (with the help of City of Duluth staff) have made in the past to mitigate problems with flooding, geese, and erosion. Some of their efforts have been successful (reducing the geese population) and some of them have not (the rain garden near Raven Island). It is evident that zoo staff care greatly for the grounds and will be open to trying various methods to protect Kingsbury Creek from the pollutants generated from the zoo’s day-to-day activities.

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Fall Audit: November 26, 2007

There is erosion below this solar panel. The zoo could use something similar to the pavers shown in the next photo (located at another location at the zoo) or they could install a rain barrel to capture some water runoff and help prevent erosion. In general, rain barrels at any location on the zoo grounds could benefit the zoo in several ways: 1.) they could save water by using the rain barrels water for watering the many flowers they have on the grounds in summer; 2.) capturing rain water in a barrel could save some water from running off impervious surfaces and carrying pollutants to the creek; 3.) Rain barrels are a great “water quality/conservation” educational tool for zoo visitors.

The existing rock channels help prevent erosion on the site. If goose feces build up in the channels, the zoo staff could use a power washer to clean them and spill socks or pillows at the discharge point to collect the wastewater. This would keep the wastewater from getting into the creek.

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There was quite a lot of goose feces present during the fall audit. This photo was taken on the path below the main building. It is adjacent to the creek. In order to keep feces from getting into the creek, zoo staff could purchase a power washer, spill pillows, and wet/shop vacuum to wash and collect the goose feces off of the pathways during those times when a high goose population is present on the grounds. This practice would help reduce fecal coliform in the creek, a water pollutant that occurs when animal waste runs off into the creek. Geese could be deterred from gathering in these areas by planting native grasses. Another option would

be to make the area a no-mow zone, however, this may result in an increase

in weeds, which may not be aesthetically pleasing. Intentional

planting of native grasses could be a better alternative.

This photo is taken near the area where Kingsbury Creek exits the zoo on its way to St. Louis Bay. The red circle indicates where goose feces are present on the walkway. A wetland could be constructed in the creek near the existing Raven area (on the right side of this photo) in order to mitigate any water pollution introduced to the creek as it runs through the zoo grounds. A constructed wetland would require some extensive planning and design, but SWCD staff could assist the zoo with such a project.

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The zoo was using straw to cover eroded areas in this photo – a mulching mower could be purchased and used to provide mulch for eroded areas instead of straw. This would allow mowed vegetation to be re-used and could reduce any threat of invasive species that could be present in purchased straw mulch. In the fall, zoo staff could use a mechanical direct seeding machine or a manual broadcast seeder/spreader to distribute grass seed in areas that suffered erosion over the summer from heavy visitor traffic. This equipment could also be used to apply environmentally de-icers in the winter.

There appears to be a collapse (hole) at the top of the slope next to the parking lot, which may indicate rotational movement of the wall. The zoo would need to work closely with an engineer to find a solution to this problem. The SWCD could provide assistance with this.

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There is some erosion occurring along the access rd. Sediment is being deposited from the road onto the lawn (see photo below). This could cause sediment to enter the creek through runoff. The zoo could use larger gravel to help slow down the water on the road or use a dissipation structure at the top of the hill to slow the water down.

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These two photos show that the large cedars along the creek rock wall are causing the ground to heave. This could eventually compromise the wall. The zoo could remove the trees, or work closely with an engineer to find a solution that would spare the trees. The SWCD could provide assistance with this.

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The following three photos show that movement of the riprap wall across from the lion exhibit is becoming more pronounced. There are rocks on the sidewalk and more of the fabric can be seen.

Fall audit findings – The fall audit revealed that several areas of the zoo grounds become subject to erosion from heavy visitor traffic during the spring, summer and early fall. The potential impacts of the geese population was also revealed during this audit.

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Appendix A: Basic Best Management Practices for Junior Docents, volunteers and employees at the zoo:

Q: I work here because I love animals – why should I care about the creek?

A: Many Reasons!

1. Because the creek has animals too! It has macro-invertebrates (tiny creatures that don’t have a backbone and that we can see with our naked eye) and fish too (Kingsbury Creek is a Designated Trout Stream).

2. Because the beauty of the creek draws a lot of people to the zoo. The Lake Superior Zoo is unique – not many zoos have the luxury of having a natural creek running through its grounds. The creek makes the animals feel more at home too.

Visit www.lakesuperiorstreams.org for much more information about Kingsbury Creek and its unique history and character.

Q: How can I make a positive impact on the creek when I’m working or volunteering at the zoo?

A: Here are a couple of basic Best Management Practices that the South St. Louis Soil & Water Conservation District recommends based on its evaluation of zoo grounds and practices in 2007 & 2008.

1. Keep a careful eye on the animals’ watering containers. Don’t keep the hose running continuously. Instead, check their water often and fill as needed. See illustrations below.

2. Geese love to hang out at the zoo-why wouldn’t they? It’s beautiful here. Unfortunately, they leave a lot of waste (goose poop) on the grounds and the zoo needs to remove it to keep the place looking nice. The zoo purchased a power washer in 2008 just for this purpose. To protect the creek, always wash the waste AWAY from the creek, into the grass on the non-creek side of the pathway. Goose feces contains bacteria that can diminish the water quality of the creek. The Grass will help filter the wash water before it enters ground water. Refer to the illustrations below.

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Water container full.

Hose running continuously

Flow of muddy water

Kingsbury Creek

Just like you shouldn’t keep the faucet running when you’re brushing your teeth, it’s also better to turn off the watering hoses when the animals’ containers are full.

Animal health and safety come first, but check those water containers often – make sure they’re not overflowing – water runs off these areas, makes a muddy mess, and takes dirt right to the creek.

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Kingsbury Creek.

Spray this way – away from the Creek.

Power Washer

Wand/hose

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