Tuesday, November 27, 2012

Musings: Wailua Beach Warning

The University of Hawaii Sea Grant is cautioning the county about its plans to build a concrete Path on Wailua Beach.

"While the recent and previously observed erosion episodes are temporary, similar episodic or event based erosion events are highly likely to cause management problems for infrastructure sited close to the beach in this area in the future,”  wrote Ruby Pap, Sea Grant Coastal Land Use Extension Agent, in a memo to county Parks Director Lenny Rapozo and Buildings Division Chief Dough Haigh 

At the beginning of January, the county plans to start installing 9'x8'x1.5' concrete slabs that weigh about 9 tons each on the berm of the beach, adjacent to the roadway. The slabs will be connected with steel control joints, ostensibly so the county can cut through the spacers and lift the slabs away in case they need to be removed or adjusted to response to erosion. It will be separated from the highway by a barrier wall.

As an alternative, we suggest that you look into a resilient raised wooden boardwalk design,” Pap wrote. “This option may be less costly and easier to maintain than a concrete path over the long-term, given the probability of removal that may be needed."

Pap noted that "historical shoreline positions visible in the erosion map show that shoreline position is highly variable at Wailua Beach, and the biggest erosion hazard is seasonal or episodic as opposed to a chronic long-term erosion trend."

The height of a wooden boardwalk is flexible, and need not be extensive and I believe could be compatible with a highway barrier wall,” Pap wrote. “Benefits of a raised boardwalk design include an accommodation strategy which allows for waves and erosion to migrate under the structure without causing damage or even effecting the use of the boardwalk.

Raised boardwalks are commonly constructed in beach settings around the world and serve to provide reliable access to and along the beach with minimal, negligible even, impact to the beach processes at a fraction of the coast of reinforced concrete pathways that may require repair.”

In a letter to the editor today, Judy Dalton of the Sierra Club wrote:

Building anything on a beach is an environmentally unsound idea but building a bike path on an eroding beach defies logic. The concrete path, in some places, would be as few  as 12 feet away from the ledge which is eroding from increasingly higher wave action.

The alignment for the first bike path planned up until 2 years ago for Wailua Beach is now in the ocean. How soon would it take for the currently planned alignment to be affected by rising ocean levels? 

Surfrider also opposes building a Path on Wailua Beach. The Path should instead be located on the asphalt roadway or routed behind Coco Palms.

Councilman KipuKai Kualii has asked county Planning Director Mike Dalihig and a Sea Grant representative to attend Wednesday's Council meeting “to provide an update on the erosion occurring at Wailua Beach and the impact that it may have on the multi-use path in that specific area.” Testimony may be submitted to councilmembers@kauai.gov.


Anonymous said...

I am in favor of the path, but I also think a wooden section here is a good idea.

Anonymous said...

Wood boardwalk requires footings ( ground penetration) removable concrete path requires no ground penetration.

Anonymous said...

There is no way a 9 ton slab of concrete can be considered a moveable path. what a joke!!

Anonymous said...


Floods reaching five feet above the current high tide line will become increasingly common along the nation’s coastlines well before the seas climb by five feet. Over the last century, the nearly eight-inch rise of the world’s seas has already doubled the chance of “once in a century” floods for many seaside communities.

There are two basic ways to protect ourselves from sea level rise: reduce it by cutting pollution, or prepare for it by defense and retreat. To do the job, we must do both.


Anonymous said...

ever heard of a crane?

9 tons isn't that big a deal.
9 ft X 8 ft is nothing compared to the Golden Gate bridge sections that were removed and replaced with pre-cast sections.

Best not to blather if you don't know anything on the subject or you'll look like Glenn Mickens.

Anonymous said...

We're talking about a bike path not a four-lane bridge! Be practical. What kind of expense to have a crane come in and move these slabs around?

Anonymous said...

"Wood boardwalk requires footings ( ground penetration) removable concrete path requires no ground penetration."

The above statement is not always true and even when true generally there is less disturbance to the underlying ground than with a concrete path.

Anonymous said...

County has a really bad record of improvements in that area. Muudy pond at Lydgate, proposed Wailua Bridge parking area now under sand. Now this?

Dawson said...

> 9 ft X 8 ft is nothing compared to the Golden Gate bridge sections that were removed and replaced with pre-cast sections. <

You're right. Since they laid tons of concrete on the Golden Gate bridge, they should lay tons of concrete on the eroding beaches of Kauai.

> Best not to blather if you don't know anything on the subject... <

My God, you're right again! Twice in one post! Give this man a lifetime subscription to Readi-Mix Monthly. He's earned it.

Anonymous said...

"building a bike path on an eroding beach defies logic"

That says it all!

A Buffoons will stay Buffoons...working for the government is just an accident.

Dr. Shibai

Anonymous said...

Bike path proponents just won't accept reality...it's climate change stupid. We don't need to tamper with our wild coastlines, leave them alone. Mahalo Kipukai for brining in the experts to explain it to the dummies.