A. The land drainage map shall be maintained by the city engineer and be adopted by the city council. The map shall be based upon subsurface drainage information available from site-specific studies and from soils studies by the National Resource Conservation Service. The allowable basement depth may be adjusted by the city engineer if more accurate site-specific studies are provided. If a discrepancy exists between the information provided by the property owner and the city’s information, the city may request additional information or studies. If a building lot is split between two or more zones, the most stringent requirements of the zones shall apply to the entire lot. The map will include the following zones:

Zone A – No basements allowed under any circumstances. These are areas where the ground water table is generally close to the surface throughout the year where even a land drainage system will be ineffective.

Zone B – Basements allowed if a land drain is present. These are areas where the water table is high for most of the year. If a land drain is not present in zone B, then the maximum basement depth allowed will be 24 inches measured between the top back of the curb and the top of the footing. A foundation drain and sump pump will be required.

Zone C – Basements allowed with foundation drains and sump pumps. These areas have mild ground water issues for a short season. Homes built in this area shall have a sump pump installed to evacuate water rather than a gravity drain system. The pumps should drain to a shallow land drain system or approved location other than the gutter. If a foundation drain is not installed in zone C, then the maximum basement depth allowed will be 24 inches measured between the top back of the curb and the top of the footing.

Zone D – Basements allowed with sump pumps. These areas rarely have ground water issues and land drains are not necessary. A sump pump pit will be installed, along with all associated plumbing and electrical, as added security for years where the water table may become a problem. A foundation drain is not required, but is recommended. If a sump pump pit is not installed in zone D, then the maximum basement depth allowed will be 24 inches measured between the top back of the curb and the top of the footing.

B. Foundation Drains. Foundation drains will be required in zones B and C and are recommended in zone D. Foundation drains may be either a perimeter drain or a single point drain connected to the gravel under the floor slab. Under either scenario, gravel shall be placed under footings to allow water to flow under the footings to the drain. Foundation drains shall be installed according to the current building code adopted by the city.

C. Sump Pumps. A sump pump basin and all necessary plumbing and electrical, according to the standard details, shall be constructed in all residential dwellings in zones B, C, and D. The sump pump shall be installed according the current building code adopted by the city. The sump pump discharge shall connect to the land drain or other appropriate location approved by the city engineer. [Ord. 08-16-2011 § 1].