South Maui is suffering from a Degraded Watershed

South Maui’s watershed is severely degraded due to poor soil management, overgrazing on uplands and ranchlands, and damage from feral ungulates that have degraded the catchment basins. The vegetation is gone and the soil is disturbed which causes increased stormwater runoff and unchecked erosion. This causes mud floods in the coastal flood plain in Kihei and Wailea that are constantly threatening neighborhoods and polluting the ocean. This condition has caused a localized climate change that contributes to reduced rainfall and exacerbates drought conditions. ( *You can read all about it in the South West Maui Watershed Plan).

Decades of bad decisions have led to a degraded watershed and increased flooding in south Maui. The development of Kihei was never planned as you might expect. For a long time since the Territory days (1900-1959) the entire area was considered a bad choice for settlement, so it was never seriously surveyed or planned for a community to live here. So the normal steps of identifying the natural watercourses, creating floodways, and protecting streams were never conducted. After WW2 most of the land was either farmland or was divided up and sold as private property. There were no distinctions or protections given for streams, gulches, wetlands, or drainage ways. 

No one took responsibility for preserving floodways and natural watershed features. 

Shamefully, no one took responsibility for preserving floodways and natural watershed features. And this is still the case today with little or no protection of watershed features. Because of poor oversight, landowners presume that their land has “entitlements”, and are often not willing to relinquish their critical watershed lands for the common good. Since the 70’s Kihei landowners started building hotels, condos, and homes all through the coastal plain, including gulches, streambeds, and wetlands. Also, the coastal sand dunes were built over, which affected the beaches and coastal erosion as well. This was all done with the approval and blessing of the administrators and local government.

County-approved Overdevelopment: 

The planning department kept approving every development, year after year, while at the same time failed to build the appropriate amount of infrastructure, in particular never building sufficient infrastructure to manage flooding and drainage. For example, even today long stretches of South Kihei road are still without curbs, sidewalks, and stormwater drains. Stormwater is not managed properly on land instead, it is allowed to be dumped untreated into the ocean.  

Floodplain Mismanagement: 

Streams and gulches run through ranchlands, and then down through and across private property. There is no responsibility for ranchers to maintain or preserve the streams, and the landowners on the floodplain have no responsibility to maintain streams, gulches, or flood plains. There are no contiguous drainageways from the watershed catchment basins to the floodplain and ocean. The Maui Zoning Map has not dedicated any contiguous/continuous drainage ways in south Maui. 

Contaminated Floodwater is a health hazard:  Floodwater in Kula Kai today is contaminated with debris, chemicals, debris, and pathogens. It is a health hazard, and high velocity flows cause more erosion and damages the watershed. 

Soils are lost in the uplands, and chemical-laden soils are sloughed off the land and flow downhill. Destructive, mud-laden stormwater, also picks up sewerage from flooded wastewater facilities and leaky cesspools. The floodwaters become a toxic mess, which some people refer to as mud-floods. These floodwaters pool in neighborhoods and roadways, and deposit deep muddy pools that can block traffic and destroy homes. All this toxic mess eventually finds its way into the ocean where it harms reefs and sea life, and can continue to have harmful effects for months afterward.            

Since the 1970s Kihei development has been driven by real estate speculation:  Kihei development has been driven by real estate speculation and not by the needs of the local population, this has led to overexploitation of lands without a corresponding investment in sustainable infrastructure. This has also contributed to a dysfunctional transportation network, a lack of proper roadways, poor pedestrian access, and deficient flood control measures. According to the G.P. 2030 Maui Island History Report, “The (1970 Kihei) 701 plan set the stage for massive real estate speculation and development.”

Kihei 701 Plan – Failure to properly plan:   Poor planning has led to today’s problems of bad traffic, flooding, and insufficient infrastructure. “The plan proposed a significant amount of development, all feeding onto South Kihei Road, without an infrastructure grid system to support the induced large volume of traffic. This inadequate roadway system coupled with the establishment of a linear pattern of single-use commercial, residential, and hotel zoning across the entire region set the foundations for an automobile-dependent region with transportation problems and urban sprawl conditions.”  Source: G.P. 2030 Maui Island History Report, page 15/34.


Sediment Loading in Stormwater Runoff, South West Maui Watershed Plan: 

The County has a Drainage Plan that will cost 133 million:  They created a plan, but have no plan to actually implement it. In 2016 the county created a Kihei Drainage Master Plan that would fix Kihei’s drainage problems with a price tag of 133 million dollars. But they never finalized it or put aside the money for that. Today the same projects would cost an estimated 160-200 million dollars. 

How do we stop this?  To help stop the ongoing damage to the watershed, we need to hold the County Council and the Planning Department responsible for all their bad choices and tell them to stop allowing bad decisions like allowing more development in the flood zones, and requiring uplands ranchers to address their erosion problems.  And finally, we need to get the County to agree on a sustainable and environmentally responsible Drainage Plan, such as the Amanda Cording Alternatives Drainage Plan, so that we can initiate actual solutions and stop the degradation of our Watershed.