About setting of rainwater runoff control facility

From September 1, 2004, regulations about title of "the regulations about adjustment of Yokohama-shi development business" were enforced.

We show procedure document of rainwater runoff control facility to prescribe in regulations Article 18 Clause 2 fifth as follows.

[Standards] of No. 5 (rainwater runoff control facility) of Section 3 of Part 2, Chapter 2, "Procedures for Development Projects" of "Ordinance on Coordination of Yokohama City Development Projects" (hereinafter, [Standards]) ) It is as follows.

• [Standards] Rainwater runoff control facility (PDF: 423KB)

It is standard of rainwater runoff control facility of guide of "the regulations about adjustment of Yokohama-shi development business".

• [Standards] Town name indication of rainwater runoff control facility setting cancellation area (PDF: 419KB)

In each ward town name display, if it is described as (part), detailed confirmation is required because the boundary of the installation exclusion area is divided by the town area. Please check separately at the counter in charge of consultation and guidance in the River Basin Management Division.

• Rainwater runoff control facility setting release area figure (PDF: 3,022KB)

In addition, setting may be exempted in area where rainwater runoff control facility is installed in land readjustment project enforcement area even in setting area. In this case, please also check the details at the window of the River Basin Management Section Consultation and Guidance Section.

"[Standards] 2 (4) C" The 30-year probability of 10-minute unit rainfall calculated from the probability rainfall intensity formula, and the 10-year probability of 10-minute unit rainfall are as follows.

• 30-year probability 10-minute unit rainfall (PDF: 1,053KB)
• 10-year probability 10-minute unit rainfall (PDF: 1,022KB)

"[Standards] The conversion storage amount of rainwater infiltration masu and rainwater infiltration pipes in 2 (8) shall be calculated as the sum of the standard infiltration amount (calculated by the formula below) and the amount of voids in accordance with the installation standard.

Qf=ko×Kf×1hr×C1×C2

• Qf： Standard penetration of installation facilities (m3/individual)
• ko： Soil saturated permeable coefficient (m / hr) (For the time being, it can be 0.05m / hr in calculating.)
• Kf： Permeable penetration of installation facilities (m2)
• C1: Impact factor (underground water level) 0.9
• C2: Impact coefficient (clozed) 0.9

Use the following results for the conversion storage amount of rainwater infiltration masu and rainwater infiltration pipes calculated by the above formula as ko = 0.05m / hr.

• Converted storage amount of rainwater infiltration pipes (PDF: 13KB)

In addition, please see the following for the full text as for "guide of the regulations about adjustment of Yokohama-shi development business".

• Housing and Architecture Bureau Ordinance on Coordination of Yokohama City Development Projects http://www.city.yokohama.lg.jp/kenchiku/takuchi/takuchikikaku/jyourei/tebiki/

(Inquiries regarding development consultation: 045-671-2898)