1. An exercise in stream restoration and redesign
Tanyard Branch
An exercise in stream restoration and redesign
Given by: Sarah Hibbs
September 29, 2003
-Degraded urban streams are a growing problem across the nation.
-watershed and riparian deforestation, road crossings, pipes and culverts, toxic pollutants, and impervious surfaces all contribute to the threats that face our urban streams.

2. What is Tanyard Branch?
An Urban Stream which runs through The University of Georgia campus, beneath Sanford Stadium
50% of Tanyard Branch is piped
Channel banks and streambed are highly eroded
Water does not meet water quality regulations
Poor habitat for insects and aquatic life
Stream is cut off from human interaction
Tanyard branch is a stream that runs through the University of Georgia campus and beneath Sanford stadium
-tanyard branch illustrates many of the problems that plague urban streams

3. The University of Georgia
Current UGA campus map

4. Tanyard Branch Now
Notice: highly eroded stream banks, the lack of substrate in the streambed, not very sinuous, trash is covering everything, riparian zones are invaded by human affects

5. Sedimentation, point source pollution, erosion, pipes running overhead

6. More point sources for pollution, storm drains with gigantic cement slabs trying to shore up the streambanks, highly eroded banks

7. More sources for point source pollution, stream channel side is completely cemented up---no riparian zone at all, undercutting

8. Streambank ersosion

9. Pipes and culverts, stream banks completely impounded, severe undercutting, no riparian zone, no ability to infiltrate and have groundwater feed stream (impounded)

10. Terraced and cement constructed bed, completely dry streambed

11. History of Tanyard Branch
Tanyard branch changes from a sinuous, unrestrained stream channel to a straightened, culverted, and highly degraded urban stream.
--even as early as 1874, the area surrounding the stream is highly urbanized, but the riparian corridor has been maintained and the stream has been allowed to flow unrestrained and inhibited.
1874 Map of Athens, Georgia
(Tanyard Branch highlighted in blue)

12. 1909 birds-eye view of Athens, Georgia
In 1893, a city reservoir on tanyard’s south branch was added, where legion pool is today. This picture shows the reservoir and a meandering stream channel. Map shows that tanyard still maintains a natural sinuous path of waterflow.
--somewhere between 1909 and 1924, photos show that the stream channel was relocated from its position to the edge of the valley to make room for the old UGA baseball field. By 1959, the ressivoir is gone and drainage maps show several first order tributaries that fed Tanyard branch (all of these tributaries are piped now)
1909 birds-eye view of Athens, Georgia

13. 1993 aerial photo of Athens, Georgia
1993 aerial view shows a highly urbanized watershed.
--research has shown us that the channel of the current tanyard creek is not in the original channel, but pushed to the edge of the valley against steep bluffs on the south bank to make more room for campus activities. The historical channel bed is through the tate center parking lot’s current location.
1993 aerial photo of Athens, Georgia
and the University of Georgia campus

14. Major Concerns Stormwater Vegetation and aquatic habitat
Problems—for urban streams and for Tanyard Branch
Strategies for repair and management
Vegetation and aquatic habitat
Geomorphic reference conditions, watershed and hydrologic assessment

15. Stormwater concerns in an urban setting
Channel instability—eroded banks and stream beds
Increased peak storm flows
Reduced baseflows
Water quality impairment (including increased temperatures, toxic pollutants, nutrients, turbidity and sediment
Habitat degradation
Biological impairment

16. Stormwater and Tanyard Branch
Lumpkin Tanyard culvert
November 10th
Lumpkin Tanyard culvert
Culvert filled to capacity, September 14th

17. Stormwater and Tanyard Branch
Sanford Tanyard culvert
Culvert filled to capacity, September 14th
Sanford Tanyard culvert
November 10th

18. How to deal with Stormwater
Traditional Methods
Conveyance—storm drains, street gutters, culverts—anything to channelize to the nearest stream
Detention—wet and dry detention ponds, stormwater wetlands
Desirable Methods
Infiltration—shifts balance of water from surface water back to groundwater—uses things like rain gardens, porous pavers and green roofs.

19. Alternative stormwater strategy 1
Cisterns that collect stormwater from rooftops and condensate from air conditioners
Retrofit sidewalks with porous paving
Include green roof design on roof upgrades of existing buildings

20. Alternative stormwater strategy 2
Vegetated infiltration basins (rain gardens) with terraced inflow dissipation
Water from parking lots is collected conventionally, but not shunted into a new storm sewer system.

21. Water from parking lot is filtered through several stilling wells, and filtered through an Alluvial fan, which slows fast moving water and allows for sediment deposit.
From the alluvial fan, water is infiltrated in a series of rain gardens

22. Alternative stormwater strategy 3
Floodplain rehabilitation—replace impervious surfaces in the floodplain with riparian wetlands
The floodplain is an integral part of biological habitat, as well as stormwater management

23. NC State’s campus stream, Rocky Branch, once had steep banks, but the floodplain has been reestablished and will soon be reforested.

24. Vegetation Suggestions
List of typical plant communities for the riparian zone and uplands
Drawn from other stream corridors in the Georgia piedmont

25. Aquatic Habitat
Clean, large sediment, consisting of pebble and cobble, for spawning and feeding
Bedrock for feeding and cover
Pools, especially deep pools, to provide refuge during drought or low flows
Riffles, for feeding and spawning, especially important for small-bodied fishes
Woody debris for feeding and cover

26. Geomorphic reference conditions, watershed, and hydrologic assessment
Tanyard channel is currently south of historic location—redesign incorporates the relocation back to its previous channel
Channelization (straightening) is another major problem for Tanyard branch—redesign will use a reference stream in the North Carolina piedmont (data includes: sinuosity, width:depth ratio, and meander belt width:width ratio) to replace the natural curves and meanders previously lost

27. Watershed assessment was conducted to assess appropriate channel size
Watershed assessment was conducted to assess appropriate channel size. Using a DOQQ for Clark County, watershed parameters were calculated using the ERDAS Imagine GIS software.
Table 1: GIS analysis results for Tanyard branch watershed
Watershed Parameter
GIS Analysis Results
Watershed area in square miles
0.782
Watershed % (forested)
20.7
Watershed % (impervious)
73.8
Watershed % (shadow—photo error)
5.4

28. Tanyard Branch Redesign of Campus
Using the campus master plan, several conceptual designs were submitted with Tanyard Branch as the focus.
Changes include: Elevated road extensions, new buildings and dorms, community outreach centers and other important features to the functioning of the center of UGA’s campus

29. University of Georgia Master Plan

30. Design Proposal A Conceptual Plan

31. Design Proposal A Detailed Plan

32. Design Proposal A Detailed Images

33. Design Proposal A Detailed Images

34. Design Proposal B Conceptual Plan

35. Design Proposal B Detailed Plan

36. Design Proposal B Detailed Images

37. Design Proposal B Detailed Images

38. Design Proposal B Detailed Images

39. The Ultimate Goal

40. GO TECH!