Earlier editions: 2026-09
Title 9 — SUBDIVISIONS›Division 914 — DRAINAGE
Contra Costa County Municipal Code Ch. 914-4 Natural Watercourses
Contra Costa County Municipal Code · 2026-10 edition · updated 2026-10-04 · Contra Costa County
Cite as: Contra Costa County Municipal Code Chapter 914-4 · Text as of 2026-10-04
914-4.002 - Protection of natural watercourses.¶
The advisory agency, in its sole discretion, may determine that a natural watercourse, or a substantial portion of a natural watercourse, in a scenic attraction or possesses significant riparian habitat, and may require that the watercourse or portion of the watercourse be protected in its natural state. The watercourse or portion required to be protected shall be referred to as a "protected watercourse."
(Ords. 89-28, 78-5).
914-4.004 - Watercourse capacity and stability analysis.¶
Before a protected watercourse may be utilized for discharge of drainage flowing through or from a subdivision, the watercourse's capacity and stability shall be substantiated through hydraulic calculations performed by a licensed engineer. Design flow volumes in excess of the watercourse's reasonable capacity shall be conveyed around the protected watercourse or shall be detained in adequate detention basins meeting the requirements of Chapter 914-12. Flow velocities in excess of those permitted by Section 9146.202 shall be attenuated using environmentally-sensitive techniques approved by the public works department.
(Ord. 89-28).
914-4.006 - Vegetation removal.¶
Vegetation removal within a protected watercourse shall be restricted to the removal of downed trees, trees that are precariously undercut and trees that have the potential of creating a major obstruction within the floodway. Removal work shall be done in an environmentally-sensitive manner, so as to minimize damage to remaining trees, undergrowth and other riparian vegetation. Older trees requiring removal of dead or diseased limbs shall be trimmed under the supervision of a tree specialist. To the maximum extent possible, undergrowth shall be preserved.
(Ord. 89-28).
914-4.008 - Side drainage.¶
Storm drainage facilities discharging into a protected watercourse shall be designed in such a manner as to minimize visual impact and erosion within the protected watercourse. Wherever possible, side drains shall be combined prior to discharging into the watercourse to reduce the number of outfalls into the watercourse.
(Ord. 89-28).
Get a plain-English answer with a citation back to this text.
Ask AI about this code