Image from the Klingle Trail EA.

DDOT has released the Klingle Valley Trail Environmental Assessment to build a trail through Klingle Valley.

For those not familiar with the area, Klingle Valley is the tributary of Rock Creek between Woodley and Cleveland Park, where a former road washed out in 1991 and kicked off a multi-decade debate about whether to build a new road or a trail that was resolved in favor of the trail in 2008. —David

Four decisions must be made before the project moves forward. These include the design of the trail, the restoration of Klingle Creek, access from the trail to the Rock Creek Trail and trail lighting. The more desirable and user friendly options also carry the highest price tags.

In all of the proposed actions, DDOT will build a multi-use trail with two trailheads, provide better storm water management and restore the creek. They would remove the existing road and all of its associated elements as well as a few trees that present a hazard.

They would add in a bioretention island on the west side and signage and/or pavement markings to connect users to the bike route on Woodley Road. Due to the steep terrain, the trail will not be designed to ADA standards. At the Indian Embassy property the trail would be lifted out of the flood plain.

Trail options: There are four options including a No Build Alternative (Alternative 1). All of the build options include 2-foot shoulders and a 7-foot swale to capture runoff. Alternative 2 would build a 10-foot-wide trail with a permeable surface, and Alternative 3 a 12-foot-wide trail. Alternative 4 is similar to Alternative 2, except that it uses an impermeable surface instead. They would all take 8-12 months to build.

Trail Alternative 3.

Access to Rock Creek Trail: Option A would build a trailhead on the east end and trail users would use the existing road to connect. Option B would narrow the 20-foot roadway to 14 feet and create a 6-foot bike/ped lane with a physical barrier and paint. Option C would also narrow the road to 14 feet but then build a multi-use trail (with a width that would vary from 6 feet to 10 feet) along the south side of the ramp that leads to the Rock Creek Trail below Porter Street, NW.

Access option C.

Lighting: Either the project will include trail lighting or it won’t. If it does, they’re looking at pole lighting and bollard lighting, using solar powered lights (which they previously noted would be difficult there) and low energy LEDs.

Stream restoration: Option A restores the most critical 420 feet of the stream, while Option B restores the entire 1,595-foot-long stream.

Analysis: For the resources studied in the EA, all options had either a benefit, minor and/or temporary negative impact or no impact (mostly no impact). The only exception was the removal of the hazardous trees.

The study also eliminated some options. It did not study a connection to Connecticut Avenue due to the steep grade. The idea of turning the Klingle-Porter intersection into a park was deemed unreasonable because it would be too disruptive and too expensive.

From a technical standpoint, Alternative 3, Access Option C, Stream Restoration Option B and the lighting option with lights are the best. Together they create a wide, permeable trail with the best possible connection to the Rock Creek Park Trail and lighting for transportation; and completely restore the stream. They also happen to be the most expensive options as seen in the table below.

The addition of lighting is critical to make the trail into be a commuter route. DDOT should make the investment.

The maintenance savings for the impermeable trail surface don’t seem worth it. They create an additional $40,000 up-front cost to save $2,000 a year, and increase runoff. Therefore, Alternative 4 should not be considered.

Choosing between Alternative 2 and Alternative 3 seems difficult at first because of the over $2 million difference between the two. That seems like a lot of money for 2 extra feet of width. It is.

Running through the numbers in Table 2 below, it appears they made a math error. In order to get the high value in the Total Cost row for Alternative 2, they added $143,000 for access option C instead of $1,430,000. The real price difference for the two is $746,000. At that price, the wider trail may be worth it — more so if they can get the woman in the drawing above to not walk down the middle of it.

The most difficult choices deal with the trail connection and the stream restoration. The road in question gets very little traffic, and so $1M+ to get a narrow sidepath seems like an unnecessary expense. It would be a plus, and possibly even required for pedestrians, but it would be nice to know what DDOT would do with the money if it weren’t spent on the connection. Complete stream restoration on the other hand, though pricey, seems like the right thing to do.

A public hearing on the EA has been scheduled for Wednesday, June 23, 2010, starting with an open house from 6-6:30 pm and presentation and comments from 6:30-8 pm The hearing will be at the National Zoo’s Visitor Center Auditorium, 3001 Connecticut Avenue, NW (Red Line to Woodley Park-Zoo). The public comment period closes July 6, 2010, and comments must be received no later than July 6, 2010.

Table of Costs for Klingle Options

Crossposted at TheWashCycle.