Installation of rainwater runoff control facilities

From September 1, 2004, the provisions concerning the title of "Ordinance on Coordination of Yokohama City Development Projects" were enforced.

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

[Standard] of Section 5 (rainwater runoff control facility) of Chapter 2, Chapter 2, "Procedures pertaining to development projects" Section 3 of the Guide of "Ordinance on Adjustment of Yokohama City Development Projects" (hereinafter referred to as [standard])) The following are as follows.

• [Standards] Rainwater runoff control facility (PDF: 611KB)

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: 538KB)

In the case of each ward town name indication, if (part) is described, 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 the River Management Section.

• Rainwater runoff control facility installation release area map (PDF: 1,673KB)

In addition, in setting area, setting may be exempted in area where rainwater runoff control facilities are installed in areas where land readjustment projects have been implemented. In this case, please check the details at the window of the River Management Division Consultation and Guidance Section.

[Standards] 2 (4) c "C" C ”The 30-year probability of 10-minute unit rainfall and 10-minute unit rainfall calculated from the probability rainfall intensity formula 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 converted storage amount of rainwater infiltration masu and rainwater infiltration pipes in 2(8)] shall be calculated by the sum of the standard penetration amount (calculated by the formula below) and the amount of voids.

Qf=ko×Kf×1hr×C1×C2

• Qf： Standard penetration amount (m3/units) of installation facilities
• ko： Soil saturation permeable coefficient (m / hr) (For the time being, calculation can be 0.05m / hr for calculation.)
• Kf： Percentage of installation facilities (m2)
• C1: Impact factor (underground water level) 0.9
• C2: Impact coefficient (clogging) 0.9

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

• Rainwater infiltration basin and rainwater infiltration pipes (PDF: 13KB)

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

• Housing and Architecture Bureau City Development Projects http://translate-en.city.yokohama.lg.jp/kenchiku/takuchi/takuchikikaku/jyourei/tebiki/

(Inquiry about development consultation, telephone: 045-671-2898)