H I A W A T H A C O R R I D O R L A N D S C A P E R E S T O R A T I O

H e n n e p i n C o u n t y H o u s i n g , C o m m u n i t y W o r k s , & T r a n s i

Hiawatha Corridor Landscape Restoration Hennepin County Housing, Community Works, and Transit

PROJECT GOALS • Improve corridor aesthetics along Hiawatha

Avenue from 32nd to 46th streets • Enhance ecological function • Calm traffic and increase pedestrian safety • Establish ongoing maintenance program • Improve pedestrian and cyclist environment ANTICIPATED TIMEFRAME • Initial improvements spring 2014 • Complete first-year improvements by fall 2014 • Subsequent phases in two- to five-year increments PROJECT PROCESS TO DATE • Contract with LHB to scope improvements • Initiate conversations between potential partners

(Hennepin County, Mn/DOT, MPRB, City of Minneapolis, watershed districts)

• Complete soil testing and tree survey • Conduct two community open houses

EXISTING TREE CONDITION • Many gaps in the tree canopy • Amur maples are tough, but are now at or past

maturity • Amur maples are considered invasive • Constrained by power lines in some areas, but a

larger scale tree would be desirable elsewhere

C o n d i t i o n o f e x i s t i n g t r e e s : • G o o d 1 4 3 37.5% • Fa i r 1 3 3 34.9% • Po o r 6 4 16.8% • Ve r y P o o r 4 1 10.7%

LEGEND good

fair

poor very poor

EXISTING SOIL CONDITIONS • Potassium very high • Phosphorus extremely high • Nitrate high but unavailable • pH higher than ideal • Higher in silt and clay than ideal • Low in organic content • Acceptable bulk density Conclusion: soil amendment will be required to support plant growth; Mn/DOT typical amendment should be sufficient

EXISTING AESTHETICS • Trees too small for scale of

corridor • Gaps in tree canopy • Trees in poor condition • Deteriorated/non-existent

understory • Extremely exposed

pedestrian and cyclist experience

• Airport “runway”

PROPOSED SOLUTION Restoration Treat the restoration of Hiawatha Avenue’s landscape as an evolution of the existing landscape, where changes are incremental, plants in good condition remain part of a changing landscape, and introductions complement elements in transition. Aesthetics Create diversity in Hiawatha Avenue’s landscape as a contrast to the uniformity of the corridor’s transportation and utility features, with signatures highlighting Blue Line stations, “ladder” streets, and built features, scale appropriate to the modes of movement and adjacent development, and signatures corresponding to the role of Hiawatha as one of the city’s primary streets. Maintenance Consider maintenance as a primary component of a designed restoration with a thoughtful balance between the planted character of the corridor and the investment required to perpetuate it. Function Reinforce critical functions of the street, balancing the speed of modes, enhancing comfort and safety of the pedestrian realm, and directing conflicting movement to safe points.

PROPOSED SOLUTION • Modular System • Respond to the “Diagonal Ladder”

Concept with enhanced intersections • Boulevard plantings to fill gaps and

replace trees in poor condition • Median plantings to narrow the

roadway experience • Trail side plantings west of trail to

provide pedestrian shelter • 100 foot- to 300 foot-long modules • Can be phased in over time as existing

tree canopy declines and funds become available

PLANT SELECTION • Mix of native, cultivars of native, and non-

native plantings • Must be proven to withstand harsh urban

environments (especially salt, high pH, and compaction)

• Provide habitat value and diversity • Avoid invasives • Suitable to the scale and aesthetic goals SOIL AMENDMENTS • Mn/DOT Specifications • Remove 6 inches of existing soil, replace with

6 inches of compost mix • Till to 16 -18 inches • Amending entire area of modules

INTERSECTION PLANTINGS

BOULEVARD PLANTINGS

2 0 0 ’ p l a n t i n g s c h e m e

1 0 0 ’ p l a n t i n g s c h e m e

MEDIAN PLANTINGS

300 ’ p l a n t i n g s c h e m e B

300 ’ p l a n t i n g s c h e m e A

TRAIL SIDE PLANTINGS

2 0 0 ’ p l a n t i n g s c h e m e

BEFORE, WHEN PLANTED, AND AT-MATURITY IMAGES BOULEVARD AND TRAIL SIDE PLANTINGS

BEFORE, WHEN PLANTED, AND AT-MATURITY IMAGES MEDIAN PLANTINGS