17.56.130 Shallow groundwater area development standards.
Development in shallow groundwater areas shall be subject to the following standards:
1. Wetlands, as defined by either the Corps of Engineers or the Environmental Protection Agency, may not be included as part of any buildable subdivision or development lot.
2. Wetlands may not be included in area requirements for lots or for calculation of density.
3. The Planning Commission may require wetlands to be fenced if it finds the wetlands are detrimental to public health, safety, or welfare.
4. Drainage water from the proposed new development may not be placed upon nor pass through other properties, except:
a. Where a pre-existing drainage system of adequate capacity is already in use, or
b. Where a permanent drainage easement of a size sufficient to carry projected flows has been obtained and a statement from the owners of both the host and guest properties is executed on proper deeds duly recorded with the county recorder specifying the following:
i. The city will held harmless from all damages or injuries resulting from water pollution and flooding from drainage crossing the property.
ii. The property owner will allow the owner of the easement to enter onto the property to maintain the drainage facility on the easement.
iii. The drainage channel can be placed in a pipe or culvert at such time as deemed appropriate by the owner of the easement.
5. Drainage from the proposed new development will not be placed in an irrigation ditch or irrigation canal originally constructed for irrigation purposes, except where a written easement running with the land has been recorded and the approval of, and signature by, all irrigation and canal companies whose ditches or canals cross the development areas or that may receive surface drainage is obtained These recorded instruments shall include the following:
a. The city will be held harmless from all damage or injury resulting from flooding, water pollution, or high ground water from drainage in the ditch or canal;
b The irrigation ditch or canal can be placed in a pipe or culvert when deemed necessary by the owner of the easement;
c. The owner of property which is the subject of a development plan will provide, and record with the county recorder, a statement holding the city harmless from all damage within the project resulting from flooding or shallow groundwater;
d. A disclosure statement will be placed upon all subdivision plats in the subject area, stating that the subdivision lot is in an area potentially subject to flooding or shallow groundwater problems; and
e. Drainage easements will be granted to the city and drainage facilities will be installed as part of the development at developer's expense.
6. No building shall be constructed in a shallow groundwater area of the city where the building proposed to be built includes a basement, unless prior to the issuance of the building permit, the owner shall produce a statement which has been recorded on proper deeds with the County Recorder, and the obligations of which run with the land and bind future owners of the property, stating that the city will be held harmless from all damages or injury resulting from flooding or any other damage resulting from a shallow groundwater area.
7. A comprehensive drainage and grading plan may be required of the developer of any property within a shallow groundwater area. The plan addressing the following points shall be approved by the D.R.C. before final residential subdivision approval, or approval is given for any residential subdivision, commercial, or industrial development or building.
a. Approval of, and signatures by, all irrigation and canal companies if their ditches or canals cross the development area, or if surface or subsurface drainage is to outfall into the ditch or canal.
b. Quantities of run-off shall be determined for the complete development area by any engineering method acceptable to the D.R.C.
c. At all outfall points from the development, quantities of run-off for a “ten-year” storm shall be determined and indicated on the plan in cubic feet per second.
d. The capacity of any irrigation ditch, storm drain, or other channel shall be determined from the inlet point to the outfall point of the channel if it is to be used for runoffs. If there is a sufficient capacity to handle added flows, it will not be used.
e. A topographic map shall be prepared indicating sufficient slopes in all areas to take surface drainage water into the designated street or storm drain. Water will not be allowed to pond any place other than a designated detention basin.
f. A plan of all proposed curbs, gutters, and cross-gutters shall be submitted. Such plan shall indicate on each curb the proposed grade, directions gutter capacity of flow, and quantities of flow.
g. No building permit shall be issued in any development until the required subsurface and storm drainage system has been constructed and is in operable condition.
h. Accompanying the drainage and grading plan shall be a soil test provided by a Licensed Professional Engineer for all areas in which underground private and public utilities will be installed. The engineer's statement must indicate what remedial action must be taken to stabilize utility lines to assure that they will not shift, buckle, or lose alignment.
i. The engineering plan shall include a cross-section acceptable to the D.R.C. of a proposed utility trench showing configuration and type of materials to be used in backfill and as a “bed” for utility lines.
j. All water mains in shallow groundwater areas must be poly wrapped. areas must be poly wrapped. (Ord. 99-13, adopted, 2000)