Douglas County to spend over $300k to solve Johnson Lane drainage issues

The Douglas County Board of County Commissioners authorized the County to enter into an Interlocal Agreement with the Carson Water Subconservency District
(CWSD), providing $95,000 from the General Fund to match a $285,000 grant obtained from the Federal Emergency Management Agency (FEMA) to complete an Area Drainage Master Plan (ADMP) for the Johnson Lane community at their meeting on April 6, 2017. The plan will look at all of drainage areas affecting Johnson Lane in a comprehensive manner and prioritize a list of projects to restore historic drainage patterns and provide flood protection.

The ADMP will include a list of projects which will be identified to provide flood protection from the 25-year, 24-hour storm, which is the County standard level of protection. A list of projects to provide protection from the 100-year storm will also be developed if the board wishes to provide flood protection above county minimum requirements. The ADMP will examine numerous "soft" or "nonstructural" solutions to the flooding including; parcel Best Management Practices (BMP), revegetation, individual lot management plans, and contour trenching.

The Johnson Lane Community experienced significant flood events throughout its history. As historic open space has been developed and population density increased, the damage to both public infrastructure and private property has become more costly. According to the Nevada Division of Emergency Management (DEM), the 2014 flash floods caused an estimated $927,205 in damage to public infrastructure and $1,556,983 in damage to private property. The 2015 flash floods caused an estimated $2,213,539 in damage to public infrastructure. DEM did not estimate the damage to private properties after the 2015 flood events.

“Solutions to the stormwater runoff in Johnson Lane have never been studied in a comprehensive manner,” said County Engineer Erik Nilssen. “This grant gives us the funding necessary to really take a look at the area and assess the drainage needs of the Johnson Lane community. It will also provide a list of projects prioritized based on the ability to help the most number of residents for the least amount of money.”

A national request for proposals was advertised and all interested engineering firms were encouraged to apply. The proposals were ranked by County and CWSD staff. J.E. Fuller Hydrology and Geomorphology based in Tempe, Arizona was selected based on their experience completing ADMPs. “This is not an all-purpose engineering firm with a stormwater section,” stated Nilssen. “This is a firm that specializes in storm water and flood solutions. I am ecstatic that they were interested in doing work in Douglas County.”

The CWSD is classified as a "cooperating technical partner" with FEMA. This designation makes them eligible for grants the County is not eligible for on our own. The CWSD still needs to approve the study , but the County is expecting approval at their next board meeting on April 19, 2017.

“CWSD requested the grant on our behalf and will manage the financial reporting to FEMA while County staff manages the project,” said Nilssen.